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RECREATIONAL EXERCISE IN ARTHRITIS
MUSCULOSKELETAL MEDICINE
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RECREATIONAL EXERCISE IN ARTHRITIS Marian A. Minor, PT, PhD, and Nancy E. Lane, MD
There is growing interest in the relationship between physical activity, exercise, and health. Prolonged inactivity and poor fitness are clearly associated with increased mortality and morbidity. Whether inactivity arises from a selfselected sedentary lifestyle or the diagnosis of arthritis, the threat to health and longevity is similar and clear. Inactivity is as important as smoking, obesity, and elevated cholesterol in increasing the likelihood of coronary artery disease, atherosclerosis, hypertension, diabetes, and some types of ~ a n c e rStudies .~ have shown increased physical activity decreases the risk of coronary artery disease, improves blood pressure, assists in weight reduction, improves mood, and enhances well-being.IR,37 Yet, individuals with chronic musculoskeletal diseases, including osteoarthritis, low back pain, inflammatory arthritis, and others with physical function limitations, have been left out of exercise recommendations. Exercise has had a controversial role in the treatment of arthritis patients. Exercise was long proscribed in arthritis for fear that vigorous motion to the arthritic joint could damage delicate periarticular tissues. Therefore, rest was prescribed because rest was thought to have a healing effect on inflamed or painful joints. However, for the person with arthritis, the consequences of prolonged inactivity add measurably to the problems of pain, stiffness, loss of motion, weakness, functional limitation, and disability. Recent studies have demonstrated the safety and efficacy of exercise for arthritis and chronic musculoskeletal pain patients. This article reviews the benefits of regular physical activity for general health, the literature on conditioning exercise in arthritis, and exercise recommendations for comprehensive management.
From the Department of Physical Therapy, School of Health Related Professions, and the Department of Internal Medicine, University of Missouri, Columbia, Missouri (MAM); and the Department of Medicine, Division of Rheumatology, School of Medicine, University of California, San Francisco, San Francisco, California (NEL)
RHEUMATIC DISEASE CLINICS OF NORTH AMERICA
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VOLUME 22 * NUMBER 3 AUGUST 1996
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BENEFITS OF REGULAR PHYSICAL ACTIVITY FOR GENERAL HEALTH
Regular physical activity may beneficially affect many chronic diseases and conditions that constitute a significant public health burden in the United States. Both basic and epidemiologic studies have generated evidence of the benefits of physical activity in the elderly. Physical activity is defined as any bodily movement produced by skeletal muscles that results in caloric expenditure.8 Exercise is a subcategory of physical activity that is planned, structured, repetitive, and results .in improvement or maintenance of one or more facets of physical fitness. Physical fitness is something that people possess or achieve, such as muscular endurance, muscular strength, body composition, and flexibility. Thus, physical activity and exercise can be considered potentially health-related behaviors that may improve or maintain several aspects of physical fitness.8The impact of physical activity on the development, severity, and progression of chronic diseases is now just beginning to be reported. The influence of physical activity on mortality from coronary artery disease is substantial. A 17-year prospective study of elderly men and women in California found a significant beneficial effect of baseline physical activity on all causes of mortality after adjustment for age, socioeconomic status, health status, smoking, weight, and alcohol intake, although deaths due to coronary artery disease accounted for the largest proportion of mortality.21A prospective study of elderly men from Honolulu found coronary heart disease (CHD) mortality was lower among the men with increased physical activity.I3Other studies have reported a positive impact with physical activity on blood pressure and cholesterol in elderly p0pulations.4~ Non-insulin-dependent diabetes mellitus (NIDDM) is one of the most prevalent chronic diseases in the elderly. Physical activity has been shown to prevent or delay the onset of NIDDM directly through altering the sensitivity of insulinz3 or indirectly through prevention of ~ b e s i t y . ~ Physical activity plays an important role in the health of the elderly by maintaining physical function independent of the presence of any. existing chronic diseases. A 4-year prospective study of 6981 men and women from three communities found that the risk of losing mobility was significantly associated with low physical activity levels.z6Physical activity in the form of walking, gardening, or vigorous exercise three or more times a week has the strongest association with maintenance of mobility.26Although speculations about an inverse association between physical activity and cancer have been made since the 1920~:~this association is far from understood. Evidence for a protective effect of exercise on the risk of cancer has been reported for colon cancer and breast cancer; prostate cancer has been reported but the evidence is far from ~omplete.~ Osteoporosis is a disease that results from bone loss such that the bone becomes fragile and fractures under very little stress. Although prolonged inactivity is associated with loss of bone mass, regular physical activity is associated with a higher bone mass. Exercise intervention studies and randomized exercise trials have generally found a positive effect of exercise on bone mass parameters.'OP 48 Recent studies have begun to examine if exercise increases bone mineral density or slows the bone loss associated with aging and results in less fractures. Retrospective studies have found that people employed in more sedentary occupations through mid-adulthood were more likely to have a hip fracture in later life.I2 Although osteoarthritis is a disease that results from degeneration of the articular cartilage, and although specific forms of leisure time activities have
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been associated with the accelerated development of osteoarthritis in weightbearing short-term prospective studies have found that moderate supervised exercise can benefit subjects with osteoarthritis.z2,32 (This subject will be covered in further detail later in this article.) In summary, the available epidemiologic evidence, when coupled with relevant clinical research, suggests that physical activity has the potential to favorably influence the development and progression of a variety of chronic diseases and conditions that are a burden to public health. The evidence also is beginning to emerge for elderly populations. Per Olaf Astrand, one of the originators of exercise physiology, stated, “As a consequence of diminished exercise tolerance, a large and increasing number of elderly people will be living below, at, or just above ’thresholds’ of physical ability, needing only a minor intercurrent illness to render them completely d e ~ e n d e n t . ”Physical ~ activity can improve physical function, and as physical function improves, there is a propensity to perform even greater amounts of physical activity. These improvements in physical activity may be essential to the quality and perhaps quantity of life of elderly persons and persons with chronic disease. RECOMMENDATIONS FOR PHYSICAL ACTIVITY FOR THE GENERAL POPULATION
It is important to recognize the distinction between exercise training to improve physical fitness and physical activity to improve or maintain health. Early investigations in the field of exercise science often studied athletes. The research focus was generally to improve competitive performance. Therefore, much of the information about prescribing exercise to improve fitness indicated that fairly intense exercise regimens were needed; however, epidemiologic studies of health risk factors and exercise research in less fit populations reveal important information relevant to health and fitness of persons with musculoskeletal impairments and limitations in m~bility.~, 37 It is not necessary for a person to participate in an intense, highly regimented exercise program or attain a high level of athletic fitness to improve health status. Even persons with low fitness levels who engage in low intensity, but regular, physical activity are significantly at less risk for a number of degenerative and potentially fatal condition^.^ Current recommendations for regular physical activity and exercise as proposed by the American College of Sports Medicine and the Centers for Disease Control include specific recommendations for health and for fitness.3yGuidelines for the former are couched in terms of regular physical activity rather than specific exercise and recommend whole body dynamic activity performed at low to moderate intensity on most days of the week, accumulating 30 minutes of exercise on each exercise day (Table 1). This suggestion is based on both epidemiologic research and clinical trials. Guidelines for improving physical fitness, both cardiovascular and neuromusculoskeletal, continue to recommend continuous exercise bouts at higher levels of intensity and duration (Table 2).’ In addition to a modified prescription for lower levels of exercise, recommendations for exercise testing prior to participation also have been revised. Current guidelines state that men under 50 and women under 40 who are asymptomatic and have no more than one cardiovascular risk factor can begin a moderately intense exercise program with medical clearance and do not require physician supervised cardiovascular stress testing.I7 Persons with arthritis are a heterogeneous population, ranging widely in
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Table 1. RECOMMENDATIONS FOR PHYSICAL ACTIVITY FOR HEALTH
Purpose: Establish a pattern of regular physical activity to promote general health. Exercise Mode: Activities that involve large muscle groups (entire body if possible) in dynamic, repetitive motion. (Examples include walking, swimming, dancing, bicycling, rowing, aquatic exercise, calisthenics, household and garden tasks.) Frequency: Three to 4 times a week for moderate intensity; daily for low intensity. Duration: Accumulation of 30 minutes each exercise day. Intensity: Low to moderate intensity: 50%-75% of age-predicted heart rate; rating of perceived exertion = 3-5; talk test = able to converse comfortably or sing a song.
age, disease, impairments, functional goals, and interests. Some are interested in and capable of performing exercise programs with a goal of improving physical fitness. Other persons may need instruction and support to participate in cardiovascular or pulmonary rehabilitation programs. Others may not be candidates for fitness training programs but can be educated and encouraged to adopt appropriate exercise and activity habits to improve or maintain health, improve function, and reduce the risk of inactivity-related illness. REVIEW OF LITERATURE ON CONDITIONING EXERCISE IN ARTHRITIS The presence of arthritis can create serious health problems in ways other than direct consequences of disease and side effects of therapy. Arthritis is the primary cause for limitation in physical activity in adults. In persons over age 65, 12% report limitation in physical activity because of arthritis50;heart disease is a close second. Persons with a diagnosis of rheumatoid arthritis (RA) have reported that one of the first adaptations they make is to give up leisure and recreational activities, a primary source of physical activity for adults. In addition to the threat of prolonged inactivity to general health, inactivity produces many of the same signs and symptoms traditionally attributed to the arthritis disease process, namely muscle weakness and atrophy, decreased flexibility, cardiovascular deficit, fatigue, incoordination, osteoporosis, depression, and lowered pain threshold. Response and adaptation to exercise is specific to the exercise mode and the individual performing the exercise. Exercise can be classified by three functions: range of motion and flexibility, muscular conditioning, and aerobic fitness. Exercise performed to improve or maintain joint range of motion and flexibility is a low-intensity, active (or active self-assisted), dynamic motion performed daily. Exercises performed to improve muscular strength, endurance, or power include dynamic resistive and isometric activity that provides an appropriate overload to existing muscle capacity. Intensity (resistance or percentage of maximum voluntary contraction), number of repetitions, and speed of contraction are designed to meet specific goals. Frequency of muscular conditioning training is two to three times weekly. Aerobic conditioning is attained through repetitive, dynamic whole body activities performed at least 3 days a week at moderate levels of intensity. Exercise research in rheumatology has addressed safety and effectiveness of musculoskeletal and cardiovascular conditioning in a number of rheumatic diseases. Flexibility and range of motion exercises have been included as warm-
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Table 2. EXERCISE RECOMMENDATIONS FOR PHYSICAL FITNESS Cardiovascular Fitness Purpose: Increase aerobic capacity through improved cardiovascular and muscular performance. Mode: Activities that involve large muscle groups (entire body if possible) in dynamic, repetitive motion. Examples include walking, jogginghnning, swimming, dancing, bicycling, rowing, aquatic exercise. Intensity: Moderate (6O%-8OYOage-predicted maximal heart rate); rating of perceived exertion = 3-7; talk test = able to converse comfortably or sing a song. Duration: Additive or continuous bout of 30-45 minutes of aerobic activity each exercise day. Frequency: At least 3 days a week; may increase to 5 days if tolerated at moderate or low levels of exertion. Muscular Fitness Isometric Exercise Purpose: Minimize atrophy, improve tone, maintainhncrease static strength and endurance, prepare for dynamic and weight-bearing activity. Recommendations: Perform at functional joint angles Intensity: 5 70% one maximum voluntary contraction Duration: 6-second contraction Frequency: 5-1 0 repetitions daily Precautions: Decreased muscle blood flow; may increase intra-articular pressure/joint contact forces; may increase blood pressure. Exhale during contraction; avoid valsalva maneuver. Dynamic Exercise Purpose: Maintainlincrease dynamic strength and endurance; increase muscle power; improve function; enhance synovial blood flow; promote strength and remodeling of bone and cartilage. Recommendations: Capable of 8-1 0 repetitions of motion against gravity before adding resistance; use a progressive resistive regimen; perform in pain-free range; use functional activities and movement patterns. Intensity: Progress to 5 70% one repetition maximum Duration: Progress to 8-1 0 exercises, 8-1 0 repetitions Frequency: 2-3 times per week on alternate days Precautions: May increase biomechanical stress on unstable or malaligned joints. Avoid power gripping and deforming forces on involved hands and wrists. Eliminate resistive exercise in presence of joint swelling, redness, or other signs of systemic disease. Joint Protection and Exercise Recommendation DO Select low-impact activities Condition muscles prior to more vigorous activity Include flexibility and joint range of motion as key exercise components Reduce load on joint (body weight, exercise in gravity-reduced environment, such as pool or bike or rowing) Select shoes and insoles for maximum shock attenuation during weight-bearing activities Evaluate for rigidkemirigid orthotics for biomechanical correction at ankles and knees AVOID Overstretching and hypermobility Stairs, running, one-legged stance, and load carrying over 10% of body weight with hip or knee joint involvement
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up activities in the reported exercise protocols, and in some instances changes in flexibility have been measured and reported. Osteoarthritis
Risk factors for osteoarthritis (OA) of the knee include age, obesity, possibly increased bone density, higher uric acid levels, an abnormal joint motion, or prior injury to the joint.27,38 A patient with OA will consult a physician because of joint pain. Pain in osteoarthritic weight-bearing joints limits physical activity. Reduced physical activity in this patient population results in decreased aerobic capacity, decreased ability to carry out activities of daily living, and reduced 33, 41, 49 Because current therapy is aimed at reducing joint pain, these m~bility.~, patients are often told not to exercise as it might increase their symptoms. Recent studies have shown that patients with OA of the knee are able to tolerate weight-bearing exercises such as walking4, 22, 32 OA can result in decreased muscle strength in the periarticular muscles, decreased flexibility, weight gain, and decreased aerobic ~apacity.~, 33 These deficiencies are probably the result of decreased use of the joint because of pain, swelling, or limitation of motion due to bony changes. Reduced physical activity would also explain the decreased aerobic capacity and exercise endurance noted in patients with OA as compared with healthy aged matched controls?, 33,41 Goals of an exercise program in patients with OA would include increasing or maintaining joint motion, increasing the strength and endurance of periarticular muscles, increasing aerobic capacity, assisting in weight loss, and improving functional capacity in ADL. The exercise regimens needed to achieve these goals would be range of motion (ROM) and strengthening exercises as well as aerobic exercise. ROM and Strengthening Patients with OA have been found to have decreased muscle strength and selective type I1 muscle fiber atrophy that was beyond that seen in normal agi11g.4~ Because muscles function as shock absorbers and help to stabilize the joint, muscle weakness could also result in an accelerated progression of OA. Therefore, strengthening exercises for the periarticular muscles could be beneficial if they were recommended for the treatment of OA. Unfortunately, few studies have been performed in this patient population to document the value of muscle strengthening exercise. In a study by Chamberlain et al,” 42 patients with OA of the knee participated in either a home- or hospital-based exercise program to strengthen and increase endurance of the knee extensors. After 4 weeks of therapy, the patients noted decreased pain, increased function, increased maximal weight lifted, and increased endurance. There was no difference between either the home- or hospital-based exercise groups. Unfortunately, a control group of nonexercisers was not included. In another study, 32 patients with OA of the knee were divided into four treatment groups. After 6 weeks of either traditional strengthening exercises or isokinetic exercises, patients were able to strengthen the flexors and extensors of the knee.25Stretching and ROM exercises are recommended for patients with OA, but studies have not been performed in this patient population to determine the value of these exercises. Exercise recommendations for patients with OA are based primarily on experience and studies performed with RA patients. In summary, both strengthening and ROM exercises are often recommended
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for patients with OA. Good controlled studies that document efficacy are not yet available in the literature. Aerobic exercises, such as walking, running, and swimming, have become increasingly popular in the general population. Health benefits include increased physical capacity, increased exercise endurance, increased muscular strength, and assistance with weight loss. There have only been a few controlled studies examining the effect of aerobic exercise in patients with OA. Kovar et a122studied the effect of a short-term low-impact walking program on patients with OA of the knee. A total of 102 patients with documented primary OA of one or both knees were randomly assigned to an 8-week program of supervised fitness walking and patient education or standard routine medical care. Patients were evaluated and outcomes were assessed before and after the intervention using a 6-minute walking test and scores on the physical activity, arthritis impact, pain, and medication subscales of the Arthritis Impact Measurement Scale (AIMS). Patients assigned to the walking group had an 18.7% improvement in walking distance relative to their baseline assessment whereas controls showed a significant decrease. Improvements in functional status as measured by the AIMS physical activity subscale, a decrease in arthritis pain, and medication use were also observed in the walking group but not the control group. The authors concluded that a supervised fitness program and patient education improved functional status without worsening pain or exacerbating arthritis-related symptoms in patients with OA of the knee.zzAfable et alz compared a walking program with a resistance training program in 12 subjects who had symptomatic OA of the knee and self-reported difficulty with activities requiring ambulation and transfer because of their OA. In this study, both groups showed improvement in functional performance after 12 weeks of exercise. Minor et aP2 studied 120 patients, 80 of whom had OA, who were randomized into one of three treatment groups: aerobic walking, aerobic aquatics, or nonaerobic controls. The exercise regimens were well tolerated as only 7 patients (6%) dropped out of the study for arthritis-related reasons. When compared to the nonaerobic control group, the patients in the aerobic exercise groups showed significant improvements in aerobic capacity, walking speeds, depression, anxiety, and physical activity after 12 weeks of exercise.32The authors concluded that patients with OA can participate and benefit from supervised aerobic exercise programs when the programs include proper supervision and subjects are instructed in the proper ways to exercise to minimize the chance of worsening their arthritis symptoms.32
RA
It is well documented that many persons with RA are de-conditioned and less fit than their peers without arthritis. Deficits in aerobic capacity as great as 40% have been reported in persons with RA with women exhibiting greater deficits than men.I5,16, 31 Another measure of fitness is energy expenditure at submaximal workloads. Increased energy expenditure at submaximal workloads often results in early onset of fatigue, limited endurance, and poor neuromuscular control, and may interfere with performance of daily activities. Two studies that reported physiologic responses to submaximal workloads showed that arthritis subjects worked significantly harder than noninvolved controls per33 Oxygen uptake measured during treadmill walkforming the same a~tivity.'~, ing at 2.4 mph was 30% to 50% greater for subjects with arthritis.33 During submaximal bicycle ergometry, ventilation was 27% greater, heart rate was 19%
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higher, and serum lactic acid concentration was 13% greater in arthritis subjects than in control^.'^ Studies that measured muscle strength, flexibility, and functional performance reported that subjects with arthritis consistently showed significant deficits when compared with gender- and age-matched peers. Isometric knee extension was the most frequently reported test for muscle strength with deficits from 18% to 60% reported.31Flexibility deficits of both axial and appendicular joints have ranged from 20% to 60%. Functional tasks, such as time required to walk 850 m, time to ascend and descend a flight of stairs, and maximum stepping height, have shown deficits from 24% to 60%.14 Prior to formalized exercise stress testing, many health professionals assumed that pain would limit exertion and exercise tolerance in persons with arthritis; however, the majority of subjects who have performed graded exercise tolerance tests, both weight bearing (treadmill) and non-weight-bearing (bicycle), have not given pain as a reason for stopping. Factors related to exercise intolerance (e.g., exhaustion, shortness of breath, tired legs, dizziness, nausea, uncomfortable warmth) accounted for the majority of reasons for stopping e~ercise.~, 33 Stationary bicycle, walking, aquatic exercise, and low-impact aerobic dance have been investigated for effectiveness and safety in improving cardiovascular fitness. Some protocols also included resistance exercise for muscle strengthening, and all included flexibility exercise.49Intensity of the aerobic stimulus has been reported at 60% to 80% of age-predicted maximal heart rate for durations of 15 to 60 minutes. Frequency generally has been 3 to 4 times a week for 8 to 16 weeks. The majority of subjects have been between 20 and 80 years old, living independently in the community. Results of these studies have shown 12% to 21% improvement in cardiovascular performance and zero to 55% increase in muscle strength, as well as significant increases in flexibility. Traditional measures of arthritis disease activity, such as grip strength, 50-foot (15.24 m) walking time, and articular index, have demonstrated either improvement or no change in disease activity or severity. Measurements of function and health status also showed significant improvement in areas of physical and social activity, depression, anxiety, and self-c~ncept.~~, 49 The findings of these studies demonstrated that although many people were de-conditioned when they began an exercise program, most were able to exercise at levels necessary to produce a training effect and made significant gains in fitness, health status, and function. Studies of resistance training for muscle strengthening have indicated that increases in strength and muscle hypertrophy are possible and associated with improved function and decreased pain.35In a controlled trial of resistance training in persons with RA compared with age-matched controls without known disease, 12 weeks of twice-weekly exercise resulted in strength increases of 45% and changes in protein metabolism, indicating an increase in protein synthesis and decrease in protein oxidation. Levels of circulating cytokines and tumor necrosis factor also were reduced following exercise.& The longest follow-up of a conditioning exercise study was 5 years. In this study, roentgenograms were taken at the beginning and end of the study period. At the 5-year follow-up, individuals who reported more than 5 hours of exercise per week (eg., walk, jog, bicycle, swim, cross-country ski) showed less progression of joint damage, less hospitalization, less work disability, and no difference in clinically active joints than those who did not exercise.36 An unexpected and not understood finding is the significant reduction in joint swelling experienced by some persons with RA following participation in aerobic exercise.28,32 A possible explanation for this finding may be increased
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synovial blood flow, which has been shown to occur with dynamic and intermittent weight-bearing exercise by persons with knee effusions.*” The fact that persons with RA can engage in effective conditioning exercise without causing an increase in disease activity creates a major opportunity for fitness and improved health. The additional possibility that exercise may have a beneficial effect on the disease symptoms raises important questions regarding an expanded role for exercise in comprehensive management. Summary
Regular physical activity is important. People who exercise regularly live longer and are healthier than people who are sedentary.6 In the past, persons with arthritis were cautioned to rest and avoid vigorous activity. Although persons with arthritis tend to be less fit than their noninvolved peers, recent studies demonstrate that many persons with arthritis can safely participate in appropriate conditioning exercise programs to improve cardiovascular fitness, muscle strength, psychosocial status, and functional status.’6, 45,4y These studies also report good subject retention and maintenance of exercise behaviors in this population.22,32, 40 EXERCISE RECOMMENDATIONS Arthritis-Related Considerations
Extra-articular manifestations of systemic inflammatory diseases should be assessed and considered in the exercise prescription. Systemic involvement in many of the arthritides requires that a careful history and physical precede any conditioning exercise program. Pericarditis, nephritis, and vasculitis preclude increased activity. Pulmonary fibrosis may limit ventilation and limit safe exertion at high intensity. Signs of active, systemic disease should be heeded, and the initiation of more vigorous exercise delayed while awaiting effective medical control. Cardiovascular and pulmonary complications may limit exercise capacity, particularly in diseases with a major systemic component, such as systemic sclerosis, systemic lupus erythematosus, and RA. The seronegative spondyloarthropathies (ankylosing spondylitis, psoriatic arthritis) may be associated with heart involvement and conduction defects. In general, these limitations do not interfere except during high-intensity exercise. Articular manifestations of arthritis should be considered in terms of active inflammation and joint integrity. Inflamed joints are particularly vulnerable to injury. Overuse of an actively inflamed joint may aggravate the inflammatory process and increase joint damage. Synovial tissue ischemia, increased intraarticular temperature and pressure, and the presence of immune complexes are associated with joint inflammation. Although the salutary effects of active and intermittent weight-bearing exercise are still being investigated and de~cribed,’~, 19, 20, 44 current knowledge cautions against vigorous activity in the presence of active inflammation. Joint Protection
Painful, swollen joints need to be protected from deforming forces and unnecessary joint stress. Acute joint inflammation should be controlled prior to
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conditioning levels of exercise. This may require a course of drug therapy or joint aspiration. Rest in the form of protective splints and activity modification also may be necessary. For a disease flare in one or a few joints, it is often possible to alternate modes of exercise so that the exercise habit is maintained and joints are protected. Joints that demonstrate radiographic evidence of loss of joint space or damaged cartilage, laxity or tightness in periarticular tissue, chronic effusion, or malalignment are highly susceptible to activity-related injury. Joint pain and swelling following activity should be treated as an "overuse" or athletic injury, and preventive steps should be taken to strengthen the joint in preparation for a return to activity. If joint integrity or stability is not amenable to change, activity modifications can decrease the amount of joint stress. A clinical knowledge of biomechanics is essential. For example, intra-articular pressure in the hip can be reduced up to 50% by use of a cane in, the contralateral hand during arnb~lation.~~ Biomechanical stress at the knee joint increases with faster walking speed. Stair climbing produces the greatest hip joint pressures of any locomotor
The Exercise Prescription
A comprehensive exercise program can be arranged using the three components of a fitness program: warm-up, aerobic exercise period, and cool-down. Within this framework it is possible to include individualized exercises to improve or maintain flexibility, ROM, muscle strength and endurance, and cardiovascular fitness and health. Specific therapeutic goals and disease-related considerations for joint protection, progressive grading, and self-management strategies also are easily accommodated. For example, an extremely de-conditioned person initially may require a program to increase flexibility and strength to prepare for more vigorous and weight-bearing activities. When the person is able to perform 8 to 10 repetitions of these exercises within a 15-minute period, the patient will be able to add a short aerobic component, such as 5 minutes of walking or stationary bicycling, gradually progressing to 10 to 30 minutes. If a disease flare occurs or there is increased joint pain, the patient can reduce aerobic activity and perform only the warm-up routine until the acute episode resides. In this way, the exercise habit is maintained and the individual gains knowledge and exp'erience to selfmanage exercise and activity. Warm-up or Pre-aerobic Component
This component provides a neuromuscular and cardiovascular warm-up and is essential to the exercise routine. During this time, exercises are done for ROM, flexibility, and to prepare the body for more vigorous activity. Some strengthening exercise also can be performed at this time. This warm-up is needed for exercise safety by all exercisers, and is particularly important for the person with arthritis. The warm-up routine can be designed to incorporate individualized ROM and strengthening exercises and serve as the traditional home exercise program. Aerobic Component
The aerobic exercise component provides the stimulus for adaptation and training of cardiovascular efficiency, muscular endurance, and activity tolerance.
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It is this dynamic, repetitive exercise requiring the use of large muscle groups that appears to benefit general health, emotional status, weight management, self-concept, and fatigue. Exercise modes that have demonstrated efficacy include walking, combination of aquatic aerobics and walking, low-impact aerobic dance, and stationary bicycle. The aerobic component can be designed to meet individual needs and variations in disease activity. Experience with and availability of a variety of aerobic activities give the exerciser freedom to alternate modes. A flexible prescription of intensity, duration, and frequency that the client understands and can adjust to meet daily needs promotes self-management skills and appropriate activity levels. The use of interval training techniques (i.e., alternate bouts of brisk and low-intensity activity) and additive bouts of exercise (i.e., add three 10-minute exercise bouts during the day for 30 minutes of exercise) enable even the most de-conditioned and sedentary person to safely engage in healthpromoting physical activity.39 Cool-down Component Once the client is performing 10 minutes or more of aerobic activity at an intensity of 70% or more of age-predicted heart rate (moderate intensity), a 3to 5-minute cool-down period is recommended. During this time, exertion is reduced to low intensity and gentle, static stretching of exercised muscles is performed. The goal of the cool-down period is to allow the cardiovascular response to safely adjust to less demand and to gently stretch muscle to minimize the possibility of delayed onset of muscle soreness. As with the warm-up routine, low-intensity cool-down activities can be designed and used in a daily program that provides general as well as therapeutic benefit. The warm-up and cool-down may be combined to form a 25- to 30minute exercise routine for flexibility, strength, and pain management without the more intense aerobic period. These routines can be used on days when aerobic exercise is not done. Resistance Training Recommendations for physical. fitness for the general population now include guidelines for muscle strengthening. Maintaining muscle mass and strength is considered an important part of good health and fitness. Appropriate resistance training in persons with RA and OA can result in muscle strengthening, improved function and independence, and increased lean body mass without increased joint pain or disease activity. Eight to 10 exercises at 8 to 12 repetitions each performed at least twice a week is the basic recommendation for health-related strength training.' Knowledge of disease process, biomechanics, and joint protection principles must form the foundation for any weight training program for clients with multiple joint involvement. The principles of circuit resistance training appear to be appropriate for persons with arthritis. This mode of exercise, designed to improve upper and lower body strength and provide an endurance training effect, employs low resistance with repetitions to mild fatigue, and is easily graded and progressed. Exercise Progression and Maintenance
The factors most closeky associated with successful maintenance of exercise are confidence in the ability to be physically active, low to moderate intensity
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activity, enjoyment of the activity, social support from family and friends, and reinforcement and self-management skills.39Exercise recommendations that include strategies to incorporate these factors will promote successful adoption and maintenance of appropriate exercise behaviors. To establish appropriate exercise and fitness goals: Recommend "not to exceed" intensity, duration, and frequency guidelines for training and maintenance prescriptions Prescribe a starting regimen of low intensity and duration Suggest time rather than distance goals to allow individual to control pace of the activity Individualize progression of intensity and duration Suggest Alternative Modes of Exercise
Using alternate forms of exercise that vary weight bearing and joints involved also fosters maintenance of the exercise habit. A stationary bicycle is a good alternate for walking on days when knees are sore, and a walk may be a better choice of exercise than swimming on a day when hands, wrists, and shoulders are painful. Promote Self-Management and Self-Efficacy
The client must be educated for self-management so he or she can adjust the exercise routine as needed for changes in disease activity, pain, weather, availability of exercise resources, schedule conflicts, and interests. Self-efficacy for physical activity can be developed by successful experiences, such as seeing others who are successful, and assistance in reinterpreting exercise-related sensations that may be a source of concern.
CONCLUSION Traditional medical management of arthritis has emphasized medication and rest. Joint protection techniques, ROM exercises, and avoidance of vigorous activity are recommended to minimize joint stress and maintain motion. This proscriptive approach is appropriate and necessary to control inflammation and minimize tissue damage during periods of acute disease. The majority of persons with arthritis seek care when pain or dysfunction is pronounced. Accordingly, medical care focuses on resolution of the acute condition. This traditional intervention, which is appropriate in the acute condition, can be harmful when applied to the chronic state. When disease is controlled or in remission, attention must be paid to regaining strength and ROM and re-establishing appropriate physical activity. If functional deficits depended on disease progression, then persons with similar disease status and medical interventions should have similar outcomes. This is not the case, however. There is a high degree of variability in function and disability among subjects with ostensibly similar disease status and medical management. Activity levels, exercise behaviors, and fitness, in addition to
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disease-related factors, appear to be important in explaining variations in performance and outcomes.
References 1. American College of Sports Medicine Position Stand: The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness in healthy adults. Med Sci Sports Exerc 22:265-274, 1990 2. Afable RF, Bailey E, Woodard M, et al: Comparison of aerobic and strength training in persons with osteoarthritis of the knee. J Am Geriatr SOC40:17, 1992 3. Astrand PO: Physical activity and fitness. Am J Clin Nutr 55(suppl 6):1231%1236S, 1992 4. Beals CA, Lampman RM, Banwell BF, et al: Measurement of exercise tolerance in patients with rheumatoid arthritis and osteoarthritis. J Rheumatol 12:458461, 1985 5. Bjorntrop P: Obesity. In Bjorntrop P, Brodoff B (eds): Physical Activity in the Treatment of Obesity. Philadelphia, JP Lippincott, 1992, pp 708-711 6. Blair SN, Kohl HW, Paffenbarger RS, et al: Physical fitness and all-cause mortality: A prospective study of healthy men and women. JAMA 262:2395-2401, 1989 7. Blair SN, Kohl HW, Gordon NF: How much physical activity is good for health? Annu Rev Public Health 13:99-126, 1992 8. Caspersen CJ, Powell KE, Christenson GM: Physical activity, exercise and physical fitness: Definitions and distributions for health-related research. Public Health Rep 100:126-130, 1985 9. Caspersen CJ, Kriska AM, Dearwater SR Physical activity epidemiology as applied to elderly populations. Baillieres Clin Rheumatol 8:7-28, 1994 10. Cavanaugh DJ, C a m CE: Brisk walking does not stop bone loss in postmenopausal women. Bone 9:201-204, 1988 11. Chamberlain MA, Care G, Harfield B: Physiotherapy in osteoarthritis of the knees. International Rehabilitation Medicine 4:lOl-106, 1982 12. Cooper C, Wickham C, Coggon D: Sedentary work in middle life and fractures of the proximal femur. British Journal of Industrial Medicine 4769-70, 1990 13. Donohue RP, Abbott RD, Reed DM, et al: Physical activity and coronary heart disease in middle-aged and elderly men: The Honolulu Heart Program. Am J Public Health 78:683-685, 1988 14. Ekblom B, Lovgren 0, Alderin M, et al: Physical performance in patients with rheumatoid arthritis. Scand J Rheumatol 3:121-125, 1974 15. Ekdahl C, Andersson SI, Moritz U, et al: Dynamic versus static training in patients with rheumatoid arthritis. Scand J Rheumatol 19:17-26, 1990 16. Galloway MT, Jokl P: The role of exercise in the treatment of inflammatory arthritis. Bull Rheum Dis 42:1-4,1993 17. Gordon NF, Kohl HW, Scott CB, et al: Reassessment of the guidelines for exercise testing. Sports Med 13:293-302, 1992 18. Haskell WL. Leon AS, Casuerson Cl. et al: Cardiovascular benefits and assessment of physical activity and piysical fitness in adults. Med Sci Sports Exerc 24(suppl 6):S201-S206, 1992 19. Houlbrooke K, Vause K, Merrilees MJ: Effects of movement and weightbearing on the glycosaminoglycan content of sheep articular cartilage. Australian Physiotherapy 36188-91, 1990 20. James MJ, Cleland LG, Gaffney RD, et al: Effect of exercise on "'"Tc-DTPA clearance from knees with effusions. J Rheumatol 21:501-504, 1994 21. Kaplan GA, Seeman TE, Chone RB, et al: Mortality among the elderly in the Alameda County Study: Behavioral and demographic risk factors. Am J Public Health 77307312,1987 22. Kovar PA, Allegrante JP, Mackenzie CR, et al: Supervised fitness walking in patients with osteoarthritis of the knee. Ann Intern Med 116:529-534. 1992
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23. Koivisto VA, Yki-Jarvinen H, DeFronzo RA: Physical training and insulin sensitivity. Diabetes Metab Rev 1:445481, 1986 24. Krebs DE, Elbaum L, ORiley P, et al: Exercise and gait effects on in vivo hip contact pressures. Phys Ther 71:301-309, 1990 25. Kreindler H, Lewis CB, Rush S, et al: Effects of three exercise protocols on strength of persons with osteoarthritis of the knee. Topics in Geriatric Rehabilitation 4:32-39, 1989 26. LaCroix AZ, Guralnik JM, Berkman LF, et al: Maintaining mobility in late life 11: Smoking, alcohol consumption, physical activity and body mass index. Am J Epidemiol 137858-869, 1993 27. Lane NE: Exercise and osteoarthritis. Bull Rheum Dis 41:5-7, 1992 28. Lyngberg K, Danneskiold-Samsoe 8, Halskov 0: The effect of physical training on patients with rheumatoid arthritis: Changes in disease activity, muscle strength and aerobic capacity: A clinically controlled minimized cross-over study. Clin Exp Rheumato1 6:25>260, 1988 29. Marti 8, Knobloch M, Tschoff A, et a1 Is excessive running predictive of degenerative hip disease?: Controlled study of former elite athletes. Br Med J 299:91-93, 1989 30. McDermott M, Freyne P: Osteoarthritis in runners with knee pain. Br J Sports Med 1784-87, 1983 31. Minor MA: Physical activity and management of arthritis. AM Behav Med 13:117124, 1991 32 Minor MA, Hewett JE, Webel RR, et al: Efficacy of physical conditioning exercise in patients with rheumatoid arthritis and osteoarthritis. Arthritis Rheum 32:1396-1405, 1989 33 Minor MA, Hewett JE, Webel RR, et al: Exercise tolerance and disease related measures in patients with rheumatoid arthritis and osteoarthritis. J Rheumatol 15:905-911, 1988 34 Neumann DA: Biomechanical analysis of selected principles of hip joint protection. Arthritis Care and Research 2:146-155, 1989 35 Nordemar R, Berg U, Ekblom B, Edstrom L Changes in muscle fibre size and physical performance in patients with rheumatoid arthritis after short-term physical training. Scand J Rheumatol 5:70-76, 1976 36 Nordemar R, Ekblom B, Zachrisson L, et al: Physical training in rheumatoid arthritis: A controlled long-term study I. Scand J Rheumatol 10:17-23, 1981 37 Paffenbarger RS Jr, Hyde RT, Wing AL, et al: Physical activity, all-cause mortality, and longevity of college alumni. N Engl J Med 314:605-614, 1986 38. Panush RS, Brown DG: Exercise and arthritis. Sports Med 454-64, 1987 39. Pate RR, Pratt M, Blair SN, et al: Physical activity and public health: A recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA 273:402407, 1995 40. Perlman SG, Connell KJ, Clark A, et al: Dance-based aerobic exercise for rheumatoid arthritis. Arthritis Care and Research 3:29-35, 1990 41. Philbin EF, Groff GD, Ries MD, et al: Cardiovascular fitness and health in patients with end-stage osteoarthritis. Arthritis Rheum 38:799-805, 1995 42. Rall LC, Lundgren N, Joseph L, et al: The metabolic cost of rheumatoid arthritis (RA): Reversal with progressive resistance exercise. Arthritis Rheum 37S222, 1994 43. Reaven GM, Barrett CE, Edelstein S: Relation between leisure-time physical activity and blood pressure in older women. Circulation 83559-565, 1991 44. Roubenoff R, Roubenoff RA, Cannon JG, et al: Rheumatoid cachexia, cytokine driven hypermetabolism accompanying reduced body cell mass in chronic inflammation. Journal of Clinical Investigation. 93:2379-2386, 1994 45. Semble EL, Loeser RF, Wise CM: Therapeutic exercise for rheumatoid arthritis and osteoarthritis. Semin Arthritis Rheum 20:32-40, 1990 46. Silverton I, Dalhlstrom AW: Relation of muscular activity to carcinoma. J Cancer Res Clin Oncol 6:365-378, 1921 47. Sirea A, Susec-Michiele M: Selective type I1 fibre muscular atrophy in patients with osteoarthritis of the hiu. T Neurol Science 44149-159, 1980 48. Snow Harter C, Boux'seA ML, Lewis BT, et a1 Effects of resistance and endurance exercise on bone mineral status of young women: A randomized exercise intervention trial. J Bone Miner Res 7761-769, 1992
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49. Stenstrom CH: Therapeutic exercise in rheumatoid arthritis. Arthritis Care and Research 7190-197,1994 50. Yelin E, Lubeck D, Holman H, et al: The impact of rheumatoid arthritis and osteoarthritis: The activities of patients with rheumatoid arthritis and osteoarthritis compared to controls. J Rheumatol 14:710-717, 1987 51. Yelin EH, Felts W R A summary of the impact of musculoskeletal conditions in the United States. Arthritis Rheum 33:750-755, 1990
Address reprint requests to Marian A. Minor, PT, PhD Physical Therapy Program 106 Lewis Hall University of Missouri Columbia, MO 65211
0889-857>(/96 $0.00+ .20
RECREATIONAL EXERCISE IN ARTHRITIS Marian A. Minor, PT, PhD, and Nancy E. Lane, MD
There is growing interest in the relationship between physical activity, exercise, and health. Prolonged inactivity and poor fitness are clearly associated with increased mortality and morbidity. Whether inactivity arises from a selfselected sedentary lifestyle or the diagnosis of arthritis, the threat to health and longevity is similar and clear. Inactivity is as important as smoking, obesity, and elevated cholesterol in increasing the likelihood of coronary artery disease, atherosclerosis, hypertension, diabetes, and some types of ~ a n c e rStudies .~ have shown increased physical activity decreases the risk of coronary artery disease, improves blood pressure, assists in weight reduction, improves mood, and enhances well-being.IR,37 Yet, individuals with chronic musculoskeletal diseases, including osteoarthritis, low back pain, inflammatory arthritis, and others with physical function limitations, have been left out of exercise recommendations. Exercise has had a controversial role in the treatment of arthritis patients. Exercise was long proscribed in arthritis for fear that vigorous motion to the arthritic joint could damage delicate periarticular tissues. Therefore, rest was prescribed because rest was thought to have a healing effect on inflamed or painful joints. However, for the person with arthritis, the consequences of prolonged inactivity add measurably to the problems of pain, stiffness, loss of motion, weakness, functional limitation, and disability. Recent studies have demonstrated the safety and efficacy of exercise for arthritis and chronic musculoskeletal pain patients. This article reviews the benefits of regular physical activity for general health, the literature on conditioning exercise in arthritis, and exercise recommendations for comprehensive management.
From the Department of Physical Therapy, School of Health Related Professions, and the Department of Internal Medicine, University of Missouri, Columbia, Missouri (MAM); and the Department of Medicine, Division of Rheumatology, School of Medicine, University of California, San Francisco, San Francisco, California (NEL)
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BENEFITS OF REGULAR PHYSICAL ACTIVITY FOR GENERAL HEALTH
Regular physical activity may beneficially affect many chronic diseases and conditions that constitute a significant public health burden in the United States. Both basic and epidemiologic studies have generated evidence of the benefits of physical activity in the elderly. Physical activity is defined as any bodily movement produced by skeletal muscles that results in caloric expenditure.8 Exercise is a subcategory of physical activity that is planned, structured, repetitive, and results .in improvement or maintenance of one or more facets of physical fitness. Physical fitness is something that people possess or achieve, such as muscular endurance, muscular strength, body composition, and flexibility. Thus, physical activity and exercise can be considered potentially health-related behaviors that may improve or maintain several aspects of physical fitness.8The impact of physical activity on the development, severity, and progression of chronic diseases is now just beginning to be reported. The influence of physical activity on mortality from coronary artery disease is substantial. A 17-year prospective study of elderly men and women in California found a significant beneficial effect of baseline physical activity on all causes of mortality after adjustment for age, socioeconomic status, health status, smoking, weight, and alcohol intake, although deaths due to coronary artery disease accounted for the largest proportion of mortality.21A prospective study of elderly men from Honolulu found coronary heart disease (CHD) mortality was lower among the men with increased physical activity.I3Other studies have reported a positive impact with physical activity on blood pressure and cholesterol in elderly p0pulations.4~ Non-insulin-dependent diabetes mellitus (NIDDM) is one of the most prevalent chronic diseases in the elderly. Physical activity has been shown to prevent or delay the onset of NIDDM directly through altering the sensitivity of insulinz3 or indirectly through prevention of ~ b e s i t y . ~ Physical activity plays an important role in the health of the elderly by maintaining physical function independent of the presence of any. existing chronic diseases. A 4-year prospective study of 6981 men and women from three communities found that the risk of losing mobility was significantly associated with low physical activity levels.z6Physical activity in the form of walking, gardening, or vigorous exercise three or more times a week has the strongest association with maintenance of mobility.26Although speculations about an inverse association between physical activity and cancer have been made since the 1920~:~this association is far from understood. Evidence for a protective effect of exercise on the risk of cancer has been reported for colon cancer and breast cancer; prostate cancer has been reported but the evidence is far from ~omplete.~ Osteoporosis is a disease that results from bone loss such that the bone becomes fragile and fractures under very little stress. Although prolonged inactivity is associated with loss of bone mass, regular physical activity is associated with a higher bone mass. Exercise intervention studies and randomized exercise trials have generally found a positive effect of exercise on bone mass parameters.'OP 48 Recent studies have begun to examine if exercise increases bone mineral density or slows the bone loss associated with aging and results in less fractures. Retrospective studies have found that people employed in more sedentary occupations through mid-adulthood were more likely to have a hip fracture in later life.I2 Although osteoarthritis is a disease that results from degeneration of the articular cartilage, and although specific forms of leisure time activities have
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been associated with the accelerated development of osteoarthritis in weightbearing short-term prospective studies have found that moderate supervised exercise can benefit subjects with osteoarthritis.z2,32 (This subject will be covered in further detail later in this article.) In summary, the available epidemiologic evidence, when coupled with relevant clinical research, suggests that physical activity has the potential to favorably influence the development and progression of a variety of chronic diseases and conditions that are a burden to public health. The evidence also is beginning to emerge for elderly populations. Per Olaf Astrand, one of the originators of exercise physiology, stated, “As a consequence of diminished exercise tolerance, a large and increasing number of elderly people will be living below, at, or just above ’thresholds’ of physical ability, needing only a minor intercurrent illness to render them completely d e ~ e n d e n t . ”Physical ~ activity can improve physical function, and as physical function improves, there is a propensity to perform even greater amounts of physical activity. These improvements in physical activity may be essential to the quality and perhaps quantity of life of elderly persons and persons with chronic disease. RECOMMENDATIONS FOR PHYSICAL ACTIVITY FOR THE GENERAL POPULATION
It is important to recognize the distinction between exercise training to improve physical fitness and physical activity to improve or maintain health. Early investigations in the field of exercise science often studied athletes. The research focus was generally to improve competitive performance. Therefore, much of the information about prescribing exercise to improve fitness indicated that fairly intense exercise regimens were needed; however, epidemiologic studies of health risk factors and exercise research in less fit populations reveal important information relevant to health and fitness of persons with musculoskeletal impairments and limitations in m~bility.~, 37 It is not necessary for a person to participate in an intense, highly regimented exercise program or attain a high level of athletic fitness to improve health status. Even persons with low fitness levels who engage in low intensity, but regular, physical activity are significantly at less risk for a number of degenerative and potentially fatal condition^.^ Current recommendations for regular physical activity and exercise as proposed by the American College of Sports Medicine and the Centers for Disease Control include specific recommendations for health and for fitness.3yGuidelines for the former are couched in terms of regular physical activity rather than specific exercise and recommend whole body dynamic activity performed at low to moderate intensity on most days of the week, accumulating 30 minutes of exercise on each exercise day (Table 1). This suggestion is based on both epidemiologic research and clinical trials. Guidelines for improving physical fitness, both cardiovascular and neuromusculoskeletal, continue to recommend continuous exercise bouts at higher levels of intensity and duration (Table 2).’ In addition to a modified prescription for lower levels of exercise, recommendations for exercise testing prior to participation also have been revised. Current guidelines state that men under 50 and women under 40 who are asymptomatic and have no more than one cardiovascular risk factor can begin a moderately intense exercise program with medical clearance and do not require physician supervised cardiovascular stress testing.I7 Persons with arthritis are a heterogeneous population, ranging widely in
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Table 1. RECOMMENDATIONS FOR PHYSICAL ACTIVITY FOR HEALTH
Purpose: Establish a pattern of regular physical activity to promote general health. Exercise Mode: Activities that involve large muscle groups (entire body if possible) in dynamic, repetitive motion. (Examples include walking, swimming, dancing, bicycling, rowing, aquatic exercise, calisthenics, household and garden tasks.) Frequency: Three to 4 times a week for moderate intensity; daily for low intensity. Duration: Accumulation of 30 minutes each exercise day. Intensity: Low to moderate intensity: 50%-75% of age-predicted heart rate; rating of perceived exertion = 3-5; talk test = able to converse comfortably or sing a song.
age, disease, impairments, functional goals, and interests. Some are interested in and capable of performing exercise programs with a goal of improving physical fitness. Other persons may need instruction and support to participate in cardiovascular or pulmonary rehabilitation programs. Others may not be candidates for fitness training programs but can be educated and encouraged to adopt appropriate exercise and activity habits to improve or maintain health, improve function, and reduce the risk of inactivity-related illness. REVIEW OF LITERATURE ON CONDITIONING EXERCISE IN ARTHRITIS The presence of arthritis can create serious health problems in ways other than direct consequences of disease and side effects of therapy. Arthritis is the primary cause for limitation in physical activity in adults. In persons over age 65, 12% report limitation in physical activity because of arthritis50;heart disease is a close second. Persons with a diagnosis of rheumatoid arthritis (RA) have reported that one of the first adaptations they make is to give up leisure and recreational activities, a primary source of physical activity for adults. In addition to the threat of prolonged inactivity to general health, inactivity produces many of the same signs and symptoms traditionally attributed to the arthritis disease process, namely muscle weakness and atrophy, decreased flexibility, cardiovascular deficit, fatigue, incoordination, osteoporosis, depression, and lowered pain threshold. Response and adaptation to exercise is specific to the exercise mode and the individual performing the exercise. Exercise can be classified by three functions: range of motion and flexibility, muscular conditioning, and aerobic fitness. Exercise performed to improve or maintain joint range of motion and flexibility is a low-intensity, active (or active self-assisted), dynamic motion performed daily. Exercises performed to improve muscular strength, endurance, or power include dynamic resistive and isometric activity that provides an appropriate overload to existing muscle capacity. Intensity (resistance or percentage of maximum voluntary contraction), number of repetitions, and speed of contraction are designed to meet specific goals. Frequency of muscular conditioning training is two to three times weekly. Aerobic conditioning is attained through repetitive, dynamic whole body activities performed at least 3 days a week at moderate levels of intensity. Exercise research in rheumatology has addressed safety and effectiveness of musculoskeletal and cardiovascular conditioning in a number of rheumatic diseases. Flexibility and range of motion exercises have been included as warm-
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Table 2. EXERCISE RECOMMENDATIONS FOR PHYSICAL FITNESS Cardiovascular Fitness Purpose: Increase aerobic capacity through improved cardiovascular and muscular performance. Mode: Activities that involve large muscle groups (entire body if possible) in dynamic, repetitive motion. Examples include walking, jogginghnning, swimming, dancing, bicycling, rowing, aquatic exercise. Intensity: Moderate (6O%-8OYOage-predicted maximal heart rate); rating of perceived exertion = 3-7; talk test = able to converse comfortably or sing a song. Duration: Additive or continuous bout of 30-45 minutes of aerobic activity each exercise day. Frequency: At least 3 days a week; may increase to 5 days if tolerated at moderate or low levels of exertion. Muscular Fitness Isometric Exercise Purpose: Minimize atrophy, improve tone, maintainhncrease static strength and endurance, prepare for dynamic and weight-bearing activity. Recommendations: Perform at functional joint angles Intensity: 5 70% one maximum voluntary contraction Duration: 6-second contraction Frequency: 5-1 0 repetitions daily Precautions: Decreased muscle blood flow; may increase intra-articular pressure/joint contact forces; may increase blood pressure. Exhale during contraction; avoid valsalva maneuver. Dynamic Exercise Purpose: Maintainlincrease dynamic strength and endurance; increase muscle power; improve function; enhance synovial blood flow; promote strength and remodeling of bone and cartilage. Recommendations: Capable of 8-1 0 repetitions of motion against gravity before adding resistance; use a progressive resistive regimen; perform in pain-free range; use functional activities and movement patterns. Intensity: Progress to 5 70% one repetition maximum Duration: Progress to 8-1 0 exercises, 8-1 0 repetitions Frequency: 2-3 times per week on alternate days Precautions: May increase biomechanical stress on unstable or malaligned joints. Avoid power gripping and deforming forces on involved hands and wrists. Eliminate resistive exercise in presence of joint swelling, redness, or other signs of systemic disease. Joint Protection and Exercise Recommendation DO Select low-impact activities Condition muscles prior to more vigorous activity Include flexibility and joint range of motion as key exercise components Reduce load on joint (body weight, exercise in gravity-reduced environment, such as pool or bike or rowing) Select shoes and insoles for maximum shock attenuation during weight-bearing activities Evaluate for rigidkemirigid orthotics for biomechanical correction at ankles and knees AVOID Overstretching and hypermobility Stairs, running, one-legged stance, and load carrying over 10% of body weight with hip or knee joint involvement
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up activities in the reported exercise protocols, and in some instances changes in flexibility have been measured and reported. Osteoarthritis
Risk factors for osteoarthritis (OA) of the knee include age, obesity, possibly increased bone density, higher uric acid levels, an abnormal joint motion, or prior injury to the joint.27,38 A patient with OA will consult a physician because of joint pain. Pain in osteoarthritic weight-bearing joints limits physical activity. Reduced physical activity in this patient population results in decreased aerobic capacity, decreased ability to carry out activities of daily living, and reduced 33, 41, 49 Because current therapy is aimed at reducing joint pain, these m~bility.~, patients are often told not to exercise as it might increase their symptoms. Recent studies have shown that patients with OA of the knee are able to tolerate weight-bearing exercises such as walking4, 22, 32 OA can result in decreased muscle strength in the periarticular muscles, decreased flexibility, weight gain, and decreased aerobic ~apacity.~, 33 These deficiencies are probably the result of decreased use of the joint because of pain, swelling, or limitation of motion due to bony changes. Reduced physical activity would also explain the decreased aerobic capacity and exercise endurance noted in patients with OA as compared with healthy aged matched controls?, 33,41 Goals of an exercise program in patients with OA would include increasing or maintaining joint motion, increasing the strength and endurance of periarticular muscles, increasing aerobic capacity, assisting in weight loss, and improving functional capacity in ADL. The exercise regimens needed to achieve these goals would be range of motion (ROM) and strengthening exercises as well as aerobic exercise. ROM and Strengthening Patients with OA have been found to have decreased muscle strength and selective type I1 muscle fiber atrophy that was beyond that seen in normal agi11g.4~ Because muscles function as shock absorbers and help to stabilize the joint, muscle weakness could also result in an accelerated progression of OA. Therefore, strengthening exercises for the periarticular muscles could be beneficial if they were recommended for the treatment of OA. Unfortunately, few studies have been performed in this patient population to document the value of muscle strengthening exercise. In a study by Chamberlain et al,” 42 patients with OA of the knee participated in either a home- or hospital-based exercise program to strengthen and increase endurance of the knee extensors. After 4 weeks of therapy, the patients noted decreased pain, increased function, increased maximal weight lifted, and increased endurance. There was no difference between either the home- or hospital-based exercise groups. Unfortunately, a control group of nonexercisers was not included. In another study, 32 patients with OA of the knee were divided into four treatment groups. After 6 weeks of either traditional strengthening exercises or isokinetic exercises, patients were able to strengthen the flexors and extensors of the knee.25Stretching and ROM exercises are recommended for patients with OA, but studies have not been performed in this patient population to determine the value of these exercises. Exercise recommendations for patients with OA are based primarily on experience and studies performed with RA patients. In summary, both strengthening and ROM exercises are often recommended
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for patients with OA. Good controlled studies that document efficacy are not yet available in the literature. Aerobic exercises, such as walking, running, and swimming, have become increasingly popular in the general population. Health benefits include increased physical capacity, increased exercise endurance, increased muscular strength, and assistance with weight loss. There have only been a few controlled studies examining the effect of aerobic exercise in patients with OA. Kovar et a122studied the effect of a short-term low-impact walking program on patients with OA of the knee. A total of 102 patients with documented primary OA of one or both knees were randomly assigned to an 8-week program of supervised fitness walking and patient education or standard routine medical care. Patients were evaluated and outcomes were assessed before and after the intervention using a 6-minute walking test and scores on the physical activity, arthritis impact, pain, and medication subscales of the Arthritis Impact Measurement Scale (AIMS). Patients assigned to the walking group had an 18.7% improvement in walking distance relative to their baseline assessment whereas controls showed a significant decrease. Improvements in functional status as measured by the AIMS physical activity subscale, a decrease in arthritis pain, and medication use were also observed in the walking group but not the control group. The authors concluded that a supervised fitness program and patient education improved functional status without worsening pain or exacerbating arthritis-related symptoms in patients with OA of the knee.zzAfable et alz compared a walking program with a resistance training program in 12 subjects who had symptomatic OA of the knee and self-reported difficulty with activities requiring ambulation and transfer because of their OA. In this study, both groups showed improvement in functional performance after 12 weeks of exercise. Minor et aP2 studied 120 patients, 80 of whom had OA, who were randomized into one of three treatment groups: aerobic walking, aerobic aquatics, or nonaerobic controls. The exercise regimens were well tolerated as only 7 patients (6%) dropped out of the study for arthritis-related reasons. When compared to the nonaerobic control group, the patients in the aerobic exercise groups showed significant improvements in aerobic capacity, walking speeds, depression, anxiety, and physical activity after 12 weeks of exercise.32The authors concluded that patients with OA can participate and benefit from supervised aerobic exercise programs when the programs include proper supervision and subjects are instructed in the proper ways to exercise to minimize the chance of worsening their arthritis symptoms.32
RA
It is well documented that many persons with RA are de-conditioned and less fit than their peers without arthritis. Deficits in aerobic capacity as great as 40% have been reported in persons with RA with women exhibiting greater deficits than men.I5,16, 31 Another measure of fitness is energy expenditure at submaximal workloads. Increased energy expenditure at submaximal workloads often results in early onset of fatigue, limited endurance, and poor neuromuscular control, and may interfere with performance of daily activities. Two studies that reported physiologic responses to submaximal workloads showed that arthritis subjects worked significantly harder than noninvolved controls per33 Oxygen uptake measured during treadmill walkforming the same a~tivity.'~, ing at 2.4 mph was 30% to 50% greater for subjects with arthritis.33 During submaximal bicycle ergometry, ventilation was 27% greater, heart rate was 19%
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higher, and serum lactic acid concentration was 13% greater in arthritis subjects than in control^.'^ Studies that measured muscle strength, flexibility, and functional performance reported that subjects with arthritis consistently showed significant deficits when compared with gender- and age-matched peers. Isometric knee extension was the most frequently reported test for muscle strength with deficits from 18% to 60% reported.31Flexibility deficits of both axial and appendicular joints have ranged from 20% to 60%. Functional tasks, such as time required to walk 850 m, time to ascend and descend a flight of stairs, and maximum stepping height, have shown deficits from 24% to 60%.14 Prior to formalized exercise stress testing, many health professionals assumed that pain would limit exertion and exercise tolerance in persons with arthritis; however, the majority of subjects who have performed graded exercise tolerance tests, both weight bearing (treadmill) and non-weight-bearing (bicycle), have not given pain as a reason for stopping. Factors related to exercise intolerance (e.g., exhaustion, shortness of breath, tired legs, dizziness, nausea, uncomfortable warmth) accounted for the majority of reasons for stopping e~ercise.~, 33 Stationary bicycle, walking, aquatic exercise, and low-impact aerobic dance have been investigated for effectiveness and safety in improving cardiovascular fitness. Some protocols also included resistance exercise for muscle strengthening, and all included flexibility exercise.49Intensity of the aerobic stimulus has been reported at 60% to 80% of age-predicted maximal heart rate for durations of 15 to 60 minutes. Frequency generally has been 3 to 4 times a week for 8 to 16 weeks. The majority of subjects have been between 20 and 80 years old, living independently in the community. Results of these studies have shown 12% to 21% improvement in cardiovascular performance and zero to 55% increase in muscle strength, as well as significant increases in flexibility. Traditional measures of arthritis disease activity, such as grip strength, 50-foot (15.24 m) walking time, and articular index, have demonstrated either improvement or no change in disease activity or severity. Measurements of function and health status also showed significant improvement in areas of physical and social activity, depression, anxiety, and self-c~ncept.~~, 49 The findings of these studies demonstrated that although many people were de-conditioned when they began an exercise program, most were able to exercise at levels necessary to produce a training effect and made significant gains in fitness, health status, and function. Studies of resistance training for muscle strengthening have indicated that increases in strength and muscle hypertrophy are possible and associated with improved function and decreased pain.35In a controlled trial of resistance training in persons with RA compared with age-matched controls without known disease, 12 weeks of twice-weekly exercise resulted in strength increases of 45% and changes in protein metabolism, indicating an increase in protein synthesis and decrease in protein oxidation. Levels of circulating cytokines and tumor necrosis factor also were reduced following exercise.& The longest follow-up of a conditioning exercise study was 5 years. In this study, roentgenograms were taken at the beginning and end of the study period. At the 5-year follow-up, individuals who reported more than 5 hours of exercise per week (eg., walk, jog, bicycle, swim, cross-country ski) showed less progression of joint damage, less hospitalization, less work disability, and no difference in clinically active joints than those who did not exercise.36 An unexpected and not understood finding is the significant reduction in joint swelling experienced by some persons with RA following participation in aerobic exercise.28,32 A possible explanation for this finding may be increased
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synovial blood flow, which has been shown to occur with dynamic and intermittent weight-bearing exercise by persons with knee effusions.*” The fact that persons with RA can engage in effective conditioning exercise without causing an increase in disease activity creates a major opportunity for fitness and improved health. The additional possibility that exercise may have a beneficial effect on the disease symptoms raises important questions regarding an expanded role for exercise in comprehensive management. Summary
Regular physical activity is important. People who exercise regularly live longer and are healthier than people who are sedentary.6 In the past, persons with arthritis were cautioned to rest and avoid vigorous activity. Although persons with arthritis tend to be less fit than their noninvolved peers, recent studies demonstrate that many persons with arthritis can safely participate in appropriate conditioning exercise programs to improve cardiovascular fitness, muscle strength, psychosocial status, and functional status.’6, 45,4y These studies also report good subject retention and maintenance of exercise behaviors in this population.22,32, 40 EXERCISE RECOMMENDATIONS Arthritis-Related Considerations
Extra-articular manifestations of systemic inflammatory diseases should be assessed and considered in the exercise prescription. Systemic involvement in many of the arthritides requires that a careful history and physical precede any conditioning exercise program. Pericarditis, nephritis, and vasculitis preclude increased activity. Pulmonary fibrosis may limit ventilation and limit safe exertion at high intensity. Signs of active, systemic disease should be heeded, and the initiation of more vigorous exercise delayed while awaiting effective medical control. Cardiovascular and pulmonary complications may limit exercise capacity, particularly in diseases with a major systemic component, such as systemic sclerosis, systemic lupus erythematosus, and RA. The seronegative spondyloarthropathies (ankylosing spondylitis, psoriatic arthritis) may be associated with heart involvement and conduction defects. In general, these limitations do not interfere except during high-intensity exercise. Articular manifestations of arthritis should be considered in terms of active inflammation and joint integrity. Inflamed joints are particularly vulnerable to injury. Overuse of an actively inflamed joint may aggravate the inflammatory process and increase joint damage. Synovial tissue ischemia, increased intraarticular temperature and pressure, and the presence of immune complexes are associated with joint inflammation. Although the salutary effects of active and intermittent weight-bearing exercise are still being investigated and de~cribed,’~, 19, 20, 44 current knowledge cautions against vigorous activity in the presence of active inflammation. Joint Protection
Painful, swollen joints need to be protected from deforming forces and unnecessary joint stress. Acute joint inflammation should be controlled prior to
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conditioning levels of exercise. This may require a course of drug therapy or joint aspiration. Rest in the form of protective splints and activity modification also may be necessary. For a disease flare in one or a few joints, it is often possible to alternate modes of exercise so that the exercise habit is maintained and joints are protected. Joints that demonstrate radiographic evidence of loss of joint space or damaged cartilage, laxity or tightness in periarticular tissue, chronic effusion, or malalignment are highly susceptible to activity-related injury. Joint pain and swelling following activity should be treated as an "overuse" or athletic injury, and preventive steps should be taken to strengthen the joint in preparation for a return to activity. If joint integrity or stability is not amenable to change, activity modifications can decrease the amount of joint stress. A clinical knowledge of biomechanics is essential. For example, intra-articular pressure in the hip can be reduced up to 50% by use of a cane in, the contralateral hand during arnb~lation.~~ Biomechanical stress at the knee joint increases with faster walking speed. Stair climbing produces the greatest hip joint pressures of any locomotor
The Exercise Prescription
A comprehensive exercise program can be arranged using the three components of a fitness program: warm-up, aerobic exercise period, and cool-down. Within this framework it is possible to include individualized exercises to improve or maintain flexibility, ROM, muscle strength and endurance, and cardiovascular fitness and health. Specific therapeutic goals and disease-related considerations for joint protection, progressive grading, and self-management strategies also are easily accommodated. For example, an extremely de-conditioned person initially may require a program to increase flexibility and strength to prepare for more vigorous and weight-bearing activities. When the person is able to perform 8 to 10 repetitions of these exercises within a 15-minute period, the patient will be able to add a short aerobic component, such as 5 minutes of walking or stationary bicycling, gradually progressing to 10 to 30 minutes. If a disease flare occurs or there is increased joint pain, the patient can reduce aerobic activity and perform only the warm-up routine until the acute episode resides. In this way, the exercise habit is maintained and the individual gains knowledge and exp'erience to selfmanage exercise and activity. Warm-up or Pre-aerobic Component
This component provides a neuromuscular and cardiovascular warm-up and is essential to the exercise routine. During this time, exercises are done for ROM, flexibility, and to prepare the body for more vigorous activity. Some strengthening exercise also can be performed at this time. This warm-up is needed for exercise safety by all exercisers, and is particularly important for the person with arthritis. The warm-up routine can be designed to incorporate individualized ROM and strengthening exercises and serve as the traditional home exercise program. Aerobic Component
The aerobic exercise component provides the stimulus for adaptation and training of cardiovascular efficiency, muscular endurance, and activity tolerance.
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It is this dynamic, repetitive exercise requiring the use of large muscle groups that appears to benefit general health, emotional status, weight management, self-concept, and fatigue. Exercise modes that have demonstrated efficacy include walking, combination of aquatic aerobics and walking, low-impact aerobic dance, and stationary bicycle. The aerobic component can be designed to meet individual needs and variations in disease activity. Experience with and availability of a variety of aerobic activities give the exerciser freedom to alternate modes. A flexible prescription of intensity, duration, and frequency that the client understands and can adjust to meet daily needs promotes self-management skills and appropriate activity levels. The use of interval training techniques (i.e., alternate bouts of brisk and low-intensity activity) and additive bouts of exercise (i.e., add three 10-minute exercise bouts during the day for 30 minutes of exercise) enable even the most de-conditioned and sedentary person to safely engage in healthpromoting physical activity.39 Cool-down Component Once the client is performing 10 minutes or more of aerobic activity at an intensity of 70% or more of age-predicted heart rate (moderate intensity), a 3to 5-minute cool-down period is recommended. During this time, exertion is reduced to low intensity and gentle, static stretching of exercised muscles is performed. The goal of the cool-down period is to allow the cardiovascular response to safely adjust to less demand and to gently stretch muscle to minimize the possibility of delayed onset of muscle soreness. As with the warm-up routine, low-intensity cool-down activities can be designed and used in a daily program that provides general as well as therapeutic benefit. The warm-up and cool-down may be combined to form a 25- to 30minute exercise routine for flexibility, strength, and pain management without the more intense aerobic period. These routines can be used on days when aerobic exercise is not done. Resistance Training Recommendations for physical. fitness for the general population now include guidelines for muscle strengthening. Maintaining muscle mass and strength is considered an important part of good health and fitness. Appropriate resistance training in persons with RA and OA can result in muscle strengthening, improved function and independence, and increased lean body mass without increased joint pain or disease activity. Eight to 10 exercises at 8 to 12 repetitions each performed at least twice a week is the basic recommendation for health-related strength training.' Knowledge of disease process, biomechanics, and joint protection principles must form the foundation for any weight training program for clients with multiple joint involvement. The principles of circuit resistance training appear to be appropriate for persons with arthritis. This mode of exercise, designed to improve upper and lower body strength and provide an endurance training effect, employs low resistance with repetitions to mild fatigue, and is easily graded and progressed. Exercise Progression and Maintenance
The factors most closeky associated with successful maintenance of exercise are confidence in the ability to be physically active, low to moderate intensity
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activity, enjoyment of the activity, social support from family and friends, and reinforcement and self-management skills.39Exercise recommendations that include strategies to incorporate these factors will promote successful adoption and maintenance of appropriate exercise behaviors. To establish appropriate exercise and fitness goals: Recommend "not to exceed" intensity, duration, and frequency guidelines for training and maintenance prescriptions Prescribe a starting regimen of low intensity and duration Suggest time rather than distance goals to allow individual to control pace of the activity Individualize progression of intensity and duration Suggest Alternative Modes of Exercise
Using alternate forms of exercise that vary weight bearing and joints involved also fosters maintenance of the exercise habit. A stationary bicycle is a good alternate for walking on days when knees are sore, and a walk may be a better choice of exercise than swimming on a day when hands, wrists, and shoulders are painful. Promote Self-Management and Self-Efficacy
The client must be educated for self-management so he or she can adjust the exercise routine as needed for changes in disease activity, pain, weather, availability of exercise resources, schedule conflicts, and interests. Self-efficacy for physical activity can be developed by successful experiences, such as seeing others who are successful, and assistance in reinterpreting exercise-related sensations that may be a source of concern.
CONCLUSION Traditional medical management of arthritis has emphasized medication and rest. Joint protection techniques, ROM exercises, and avoidance of vigorous activity are recommended to minimize joint stress and maintain motion. This proscriptive approach is appropriate and necessary to control inflammation and minimize tissue damage during periods of acute disease. The majority of persons with arthritis seek care when pain or dysfunction is pronounced. Accordingly, medical care focuses on resolution of the acute condition. This traditional intervention, which is appropriate in the acute condition, can be harmful when applied to the chronic state. When disease is controlled or in remission, attention must be paid to regaining strength and ROM and re-establishing appropriate physical activity. If functional deficits depended on disease progression, then persons with similar disease status and medical interventions should have similar outcomes. This is not the case, however. There is a high degree of variability in function and disability among subjects with ostensibly similar disease status and medical management. Activity levels, exercise behaviors, and fitness, in addition to
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disease-related factors, appear to be important in explaining variations in performance and outcomes.
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Address reprint requests to Marian A. Minor, PT, PhD Physical Therapy Program 106 Lewis Hall University of Missouri Columbia, MO 65211