Assessing musculoskeletal back pain during pregnancy

ADDITIONAL ARTICLES

ASSESSING MUSCULOSKELETAL BACK PAIN DURING PREGNANCY Alyse Kelly-Jones,

MD, and Genne McDonald,

Low back pain (LBP) a$ects between 50% and 90% of women who are pregnant. The many etiologies ofLBPinclude hormonal, mechanical, postural, and vascular injluences. It is unclear whether the cause of LBP is a single entity or When diagnosing multifactorial. LBP, it is important to rule out other medical causes such as preterm labor andlor urinary tract infections. The patient’s history and physical examination can isolate the cause of LBP as musculoskeletal most of the time. The patients can then be divided into treatment groups based on the severity of their symptoms. A flow chart is provided that divides patients into three main groups and treatment optionsfor these groups. One of the most eflective means of preventing LBP during pregnancy is early education. Research has shown that patients who received education during pregnancy have less severe backache. Thus, it is important to discuss with the patient at the first prenatal visit appropria te prevention tools. This article provides diagrams demonstrating proper postural techniques for saving patients’ backs from the pain and aggravation of LBP during pregnancy. (Prim Care Update OblGyns 1997;4:205-210. 0 1997 Elsevier Science Inc. All rights reserved.)

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ELSEVIER

Low back pain (LBP) is a common problem in the general population and adds a significant cost to society.’ It is not surprising, therefore, that LBP during pregnancy also is very common. Between 50% and 90% of women develop symptoms of LBP at some time during their The prevalence inpregnancy. creases 5% for every 5 years of the patient’s age.” In up to one third of these women, symptoms are so severe that prolonged bedrest is required.3-5 Low back pain also is the greatest cause of lost work days among pregnant women.” As primary caregivers of women, obstetricians must be able to evaluate LBP complaints and plan effective treatment. All too often it has been suggested that LBP is a “normal” feature of pregnancy to be ignored without treatment.7 Pregnant and postpartum women should be allowed the same access to treatment for LBP as the rest of the population. A review of the literature, including several articles appearing in journals not routinely read by the practicing obstetrician, indicates that LBP is both preventable and treatable.‘-l I

Etiology

From the IJniversity ot Florida Health Science Center at Jacksonville Department of Obstetrics and Gynecology, Jacksonville, Florida: and ReQuest Physical Therapy. Gainesville. Florida.

Researchers have proposed many causes of LBP in pregnancy. Relaxin, a hormone produced by the corpus luteum, has been implicated in the etiology. There is a lo-fold increase in the serum levels of this hormone during pregnancy. Relaxin, acting in concert with estrogen, has been shown to relax the

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ligaments of the pelvis. The sacroiliac and symphysis pubis joints become more mobile, resulting in inflammation and discomfort.‘2 ACtual separation and displacement of the symphyseal articulation is found frequently.13 Sacroiliitis appears to be the most common cause of LBP during pregnancy and most typically presents early in the second trimester.3,10 In a 1986 study by MacLennan et a1,14 serum relaxin levels in 35 patients were measured and correlated with the degree of pelvic girdle pain and joint instability during late pregnancy. These investigators found that the highest relaxin levels occurred in the patients who were most disabled by their pain. In contrast, Petersen et al,l” found that serum relaxin concentrations were not linked with pregnancy-associated pelvic pain. In this investigation, a questionnaire was used to evaluate the degree and extent of LBP. Thus, without the use of a physical examination and positive confirmatory tests, the correlations may have been missed. Another popular theory concerns the mechanics and posture of pregnant women. During the 9 months of gestation, women undergo rapid postural changes, with the woman’s center of gravity shifting forward. As the body adjusts, the lumbar curve increases with an increase in pelvic tilt and associated shortening of the paraspinal muscles. Concurrently, the abdominal muscles are overstretched, because of the expanding uterus, and might weaken. These changes compromise the

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strength and stability of the low back and pelvis at a time when these attributes are most neededs7 Many researchers have investigated the correlation between the body mechanics of pregnant women and LBP. Ostgaard et alI6 found a positive correlation between lordosis and back pain: however, the lordosis did not increase as gestation advanced. The authors concluded that women with a particularly exaggerated lumbar lordosis were more susceptible to back pain when pregnant. Snijders et all7 studied women just before and after delivery and noted that their kyphosis and lordosis were less before delivery than after delivery. Bullock et al,l’ in a study of kyphosis, lordosis, and pelvic tilt in 34 pregnancies, found that the degree or increase of tilt did not correlate with the development of low back symptoms. A third mechanism for nocturnal LBP was put forth by Fast et alI9 after they studied 100 pregnant women and discovered that 36% of these women had pain that was sufficient to awaken them. It is known that the expanding uterus can compress the inferior vena cava and aorta of the pregnant woman. Water retention occurs during pregnancy and can increase extracellular fluid volume. Fast et alI9 theorized that the return of extracellular fluid to the expanded circulatory system volume during nighttime recumbency results in venous engorgement, especially in the pelvis. This engorgement causes increased venous pressure in structures in this area, involving the vertebral bodies and nerve roots. These neural elements of the pelvis and low back then become hypoxic, causing the patient to awaken with LBP. Fast et alI9 supported this theory with additional clinical observations in the literature. They noted that patients with congestive heart failure and spinal stenosis developed nocturnal back pain when 206

their heart failure worsened. As the failure was treated, the LBP resolved.” Similarly, women who developed LBP during menstruation also had pelvic venous congestion as shown by transuterine pelvic venography. With the administration of dihydroergotamine, a venous constrictor, the venous congestion was lessened, and the back pain improved.‘l

Diagnosis In the pregnant population, the diagnosis of LBP is based primarily on symptoms. There are few diagnostic tests that can be performed on pregnant women because of the possible harm to the fetus. The physician should inquire about prior episodes of LBP or trauma. Medical causes of LBP, such as preterm labor or urinary tract infection must be ruled out. When these medical causes are eliminated, the source of LBP is most likely musculoskeletal. Several important questions regarding the characteristics of the pain should be answered: 1. What

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is the intensity of LBP? (scale: 0 = lowest intensity and 10 = highest intensity) What is the frequency of LBP? (constant vs intermittent) What is the location of pain? (low back, posterior hips, buttocks, groin, unilateral, bilateral) Does the pain vary throughout the day? Are there any methods of pain relief? (rest, positioning, ice, heat, pressure) Is there pain with motion or rest? Are there any pain referral patterns? (to buttocks, to knees, to ankles) Are there neurological symptoms? (numbness, weakness, bowel and bladder changes) What effect does the pain have on function/daily activities/sleep patterns?

Once these questions are answered, the physician should proceed with a physical examination, looking for any gross abnormalities of the back. Some quick and basic means of assessing whether pain is musculoskeletal in origin are as follows: 1. Assess the patient’s gait pattern and standing/sitting postures. Are they indicative of pain (ie, a limp, inability to bear weight on an extremity, inability to sit folly on both buttocks)? 2. Assess trunk and lower extremity range of motion by having the patient bend forward, backward, side to side and rotate torso. Have the patient sit and lift legs, then abduct and adduct and, finally, resist this motion isometrically. If the patient has pain with these movements, this may indicate musculoskeletal pain. 3. In the supine position, have the patient flex the hip to 90°, then push on the patient’s bent knee in the direction of the table.” If the patient experiences pain, this may be indicative of sacroiliac pain. 4. Palpate the low back, buttock, posterior, and lateral hip musculature. Are these areas hypertonic or painful? If so, this may indicate musculoskeletal pain. Also palpate the lumber vertebral, sacroiliac, and symphysis pubis joints. If these areas are point tender, this may indicate sacroiliac joint dysfunction.

Treatment Pregnancy is not a cause of LBP, per se, yet its physiological changes often are the catalyst for musculoskeleta1 pain in an obstetrical patient. Treatment of LBP may not be in the realm of our expertise. A flow sheet with guidelines for the management of obstetrical LBP is shown in Figure 1. With the information from the patient’s history and physical exPrim

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Patient presents with low back pain Rule out other medical causes i.e., preterm labor or urinary tract infections

Perform a detailed history and brief physical exam and then choose a treatment group based on the findings t

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t Group A ’ Mild to moderate pain intensity o Intermittent pain o No limitations of function/daily activities/sleep o Duration less than 2 weeks ’ No pain radiation o No neurological symptoms

Education in offke o Proper postural alignment ’ Proper body mechanics ’ Basic stretching and strengthening o Proper techniques for lifting and bending o Application of superficial heat and/or ice ’ Analgesics Figure

1.

Algorithm

for evaluation

GROUPA These patients have mild to moderate pain with no limitation of function, daily activities, or sleep. There is no pain radiation into the lower

extremities and no neurological symptoms. Pain is intermittent and relieved with rest. These patients are the best candidates for office education by a health care provider. Patient education in the office should address proper postural alignment, body mechanics, and positioning during activities of 4. Number

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Referral to Physical Therapist who will: o Perform physical exam o Analyze posture, body mechanics ’ Assess range of motion, strength, structural integrity and mobility ’ Perform neurologic screen o Plan treatment

and treatment

amination, the physician can assign the patient to group A, B, or C and begin appropriate treatment.

Volume

Group C o Severe to complete limitation of function/daily activities/sleep ’ Constant pain ’ Constant pain radiation into lower extremities o Significant neurological symptoms ’ Pain is unrelieved by any means I

Group B o Moderate to severe pain intensity o Intermittent to constant pain o Moderate to severe limitation of function/ daily activities/sleep o Duration for 2 weeks to several months o Intermittent pain radiation into the lower extremities 0 Pain may/may not be relieved by rest

of low back pain during

Referral to Physiatrist or Orthopaedic/Neurosurgeon who will perform further evaluation and recommend treatment and determine specific work restrictions, if any. 4

pregnancy.

daily living (Figures 2, 3, 4, and 5). With regard to postural alignment, patients should be advised to avoid knee hyperextension, excessive anterior tilt of the pelvis, and asymmetrical standing and sitting. They also should be advised to wear supportive flat shoes. Instruction in proper body mechanics should include techniques for bending, lifting, and changing position. Advice about positioning should include use of lumbar support in sitting, proper sitting position (ie, knees at or above waist level), and use of pillows between the knees and beneath the waist when the woman is lying on her side.

Patient education should include basic stretching and strengthening exercises for key muscle groups susceptible to overstretching (abdominals, pelvic floor muscles) or shortening (lumbar paraspinals, hip flexors, and external rotators). Application of superficial heat and/or ice also may be advised. American College of Obstetricians and Gynecologists guidelines should be followed if the patient engages in an exercise regimen (ie, avoid ballistic motions and vigorous stretching of hip adductors and hamstrings).23 This information may be supplied in hand-out form, by videotape, or via group or individualized 207

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2. Example of poor postural alignment. Note the head is forward, the shoulders rounded, the sternum depressed, the pelvis is in anterior tilt, the knees are hyperextended, and weight bearing is asymmetrical. Figure

teaching sessions. Physicians may wish to consult a physical therapist or other health care personnel knowledgeable in treating obstetrical conditions.

GROUP B The patients in this group have moderate to severe pain intensity with moderate to severe limitation

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of function, daily activities, or sleep. They may have intermittent radiation of pain into the lower extremities. They have no neurological symptoms except for transient numbness above the knee. The pain can be intermittent to constant, and the pain may or may not be relieved by rest. These patients should be referred to a physical therapist with interest and experience in the obstetrical population. The American Physical Therapy Association has a section devoted to women’s health and provides continuing education regarding obstetrical LBP. Physical therapy on a short-term basis will include a thorough history: postural and body mechanics analysis; range of motion assessment; strength, structural integrity, mobility, and muscle balance analysis; a neurological screen; and palpation of muscular, ligamentous, and bony structures. Treatment usually includes instruction in proper body mechanics, postural alignment and positioning. The patient should be instructed in techniques to improve muscle balance and joint alignment to achieve neutral positioning, while taking precautions to avoid ligamentous overstretch (ie, vigorous manipulation). These techniques are commonly applied for reducing rotation of the ilia or sacrum, secondary to ligamentous laxity combined with muscle imbalance. The patient may then receive soft-tissue mobilization, deep tissue massage, and/or stretch techniques. Heat or ice may be applied to the back. Most importantly, the patient should receive an individualized home exercise program of stretching, strengthening, and positioning to maintain results of physical therapy treatment and prevent recurrence in the future. Stabilization of the lumbar spine and pelvic joints using the abdominal musculature as an exercise and during daily activities is a key component of most home programs. If diastasis recti is present, specific corrective exer-

3. Example of proper postural alignment. Note the chin is tucked, the sternum lifted, the pelvis is neutral, the knees are unlocked and weight bearing is symmetrical in both lower extremities.

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Figure 4. Example of proper resting posture. Note the upper body and knees are flexed, the knees are resting on pillows, and the trunk and head are to one side to

avoid vascular compression.

cises will be given. A maternitystyle belt or brace to stabilize the lumbar spine or pelvic joints also may be provided.

GROUP C These patients have mild to severe pain intensity with severe to complete limitation of function, daily activities, and sleep. They may have constant pain radiation into the lower extremities. They may have neurological symptoms such as constant numbness, dermatomal weakness, absent reflexes, and bowel and bladder changes. The back pain is constant and unrelieved by any means. Muscle atrophy or autonomic dysfunction is a medical emergency and requires immediate consultation. These patients should be referred to either a neurosurgeon or orthopedic surgeon for further evaluation and treatment. For all treatment groups, pharmaceutical agents should not be the

sole first-line treatment for LBP. However, acetaminophen is the most appropriate analgesic agent. Ibuprofen, and other nonsteroidal anti-inflammatory agents, which are commonly used for muscle and joint pain, should be used cautiously as they can be associated with oligohydramnios and premature closure of the ductus arteriosus, which could lead to pulmonary hypertension in the fetus.24 Patients often ask about work restrictions and bedrest to improve or alleviate the acute episode of LBP. Physicians should advise patients to avoid prolonged sitting, heavy lifting, and bending or twisting the back while lifting.‘” The majority of patients with acute LBP will not require bedrest. In fact, prolonged bedrest, more than 4 days, may lead to further deterioration of the patient’s condition. Only patients with severe initial symptoms should be considered candidates for bedrest.“”

Figure 5. Example of proper resting posture. Note the pillow between the knees, the towel roll beneath the waist, and the symmetric flexion of the legs.

There are many risk factors for the development of LBP.27 Numerous investigations have attempted to determine which factors are associated with LBP during pregnancy. Unfortunately, it is unclear in pregnant patients if any factors increase the incidence of LBP. Some studies have shown that factors contributing to LBP during pregnancy include heavy labor, smoking, parity, age, and previous history.3,“.28*2” Countering these claims, however, are studies showing that occupation, weight gain, age, parity, previous history, baby’s weight, exercise habits, and sleeping posture do not contribute to LBP during pregnanThere is obvious overlap CY*‘-‘JL~’ in the two groups, and, therefore, it is not clear which of these factors patients should try to modify. One of the most effective means of preventing LBP during pregnancy is education. Mantle et a13’ found that women who were educated about LBP had less troublesome and severe backache than a control group that did not participate in the education program. The busy obstetrician can educate patients about LBP in several ways. When the patient comes for her first visit, informational handouts can be given addressing posture, body alignment, physical fitness, stretching, proper lifting techniques, and use of lumbar supports. The patient can be exposed to posters detailing correct body alignment and posture during pregnancy when she comes for her checkups. The patient also could watch a video produced by physical therapists or other health care personnel regarding back care during pregnancy. Childbirth classes may address this issue, but, as the literature shows, it is better to begin this education early or before pregnancy occurs. &tgaard et ~1,~ found that women who had individually designed education and training programs starting early in pregnancy

had a lower incidence of LBP during their pregnancies. They also discovered that women who were physically fit had fewer back problems. Probably the best method to prevent LBP in pregnancy would be to have a physical therapist or other appropriately trained personnel provide brief instruction on proper back care either before women get pregnant or very early in their prenatal care.

Conclusion Low back pain in pregnancy is common, but fortunately, often preventable and usually responsive to treatment. It is important that the obstetrician rule out other medical causes of LBP and perform a thorough history and physical examination to determine an appropriate treatment plan for LBP. A treatment plan based on severity can be developed, which may include patient education in the office, referral to a physical therapist trained in treating pregnant patients, or referral to an orthopedic surgeon or neurologist for further evaluation. Although LBP is common during pregnancy, it is not normal and should not be dismissed without appropriate evaluation and treatment. References 1. Wilder DG. The biomechanics of vibration and low back pain. Am J Industrial Med 1993;23:577-88. Mantle MJ, Greenwood RM, Currey HLF. Backache in pregnancy. Rheumatol Rehab 1977;16:95-101. Berg G, Hammar M, Moller-Nielson J, Linden U, Thorblad J. Low back pain during pregnancy. Obstet Gynecol 1988;71:71-5. Fast A, Weiss L, Ducommun EJ, Medina E, Butler JG. Low back pain in pregnancy; abdominal muscles, sit-up performance, and back pain. Spine 1990;15:28-30. Ostgaard HC, Andersson GBJ, Karlsson K. Prevalence of low back pain during pregnancy. Spine 1991;16: 549-52.

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6. dstgaard HC, Zetherstrom G, RoosHansson E, Svanberg B. Reduction of back and posterior pelvic pain in pregnancy. Spine. 1994;19:894-900. 7. Fast A, Shapiro D, Ducommun EJ, Friedmann LW, Bouklas T, Floman Y. Low back pain in pregnancy. Spine 1987;12:368-71. 8. Rungee JL. Low back pain in pregnancy. Orthopedics 1993;16:133944. 9. Alexander JT, McCormick PC. Pregnancy and discogenic disease of the spine. Neurosurg Clin North Am 1993;4:153-9. 10. Daly JM, Frame PS, Rapoza PA. Sacroiliac subluxation: a common, treatable cause of in pregnancy. Fam Prac Res J 1991;11:149-59. 11. Andersson GBJ. Low back pain in pregnancy. In: Weinstein JN, Wiesel SW, editors. The lumbar spine. Philadelphia: WB Saunders, 1990: 840-5. 12. Hainline B. In: Devinsky 0, Feldmann E, Hainline B, editors. Neurological complications of pregnancy. New York: Raven Press, Ltd, 1994:65-76. 13. Abramson D, Roberts SM, Wilson PD. Relaxation of the pelvic joints in pregnancy. Surg Gynecol Obstet 1934;58:595-613. AH, Nicolson R, Green 14. MacLennan RC, Bath M. Serum relaxin and pelvic pain of pregnancy. Lancet 1986;2:245-6. L, Uldbjerg 15 Petersen LK, Hvidman N. Normal serum relaxin in women with disabling pelvic pain during pregnancy. Gynecol Obstet Invest 1994;38:21-3. HC, Andersson GBJ, 16. ijstgaard Schultz AB, Miller JAA. Influence of some biomechanical factors on low back pain in pregnancy. Spine 1993;18:61-5. 17. Snijders CJ, Seroo JM, Snijder JG, Hoedt HT. Change in form of the spine as a consequence of pregnancy. Digest of the 11th International Conference on medical and Biological Engineering. 1976:670-l. 18. Bullock J, Juli GA, Bullock M. The relationship of low back pain to postural changes during pregnancy. Australian JPhysiother 1987;33: 10-7. 19. Fast A, Weiss L, Parich S, Hertz G. Night backache in pregnancy-hypothetical pathophysiological mechanisms. Am J Phys Med Rehab 1989; 68:227-g.

20. LaBan MM, Wesolowski DP. Night pain associated with diminished cardiopulmonary compliance: a concomitant of lumbar spinal stenosis and degenerative spondylolisthesis. Am JPhysMedRehab 1988;67:15560. 21. Reginald RW, BeardRW, Kooner JS, et al. Intravenous dihydroergotamine to relieve pelvic congestion with pain in young women. Lancet 1987;1:351-3. 22. &tgaard HC, Zetherstrom G, RoosHansson E. The posterior pelvic pain provocation test in pregnant women. Eur Spine J 1994;3:25860. 23. American College of Obstetricians and Gynecologists. Exercise during pregnancy and the postpartum period. ACOG Technical Bulletin No. 189. Washington (DC):ACOG, 1994. 24. Briggs GG, Freeman RK, Yaffe SJ. Drugs in pregnancy and lactation. Baltimore (MD): Williams & Wilkins; 1999. 25. Dul J, Hildarbrandt VH. Ergonomic guidelines for the prevention of low back pain at the workplace. Ergonomics 1987;30:419-29. 26. Deyo RA, Diehl AK, Rosenthal M. How many days of bed rest for acute low back pain?: a randomized clinical trial. N Engl J Med 1986;315: 1064-70. 27. Frymoyer JW, Pope MH, Clements JH, et al. Risk factors in low back pain. J Bone Joint Surgery 65-A: 213-8. 28. &tgaard HC, Andersson GBJ. Previous back pain and risk of developing back pain in a future pregnancy. Spine 1991;16:549-52. 29. Svensseon H-O, Andersson GB, Hagstad A, Jansson P-O. The relationship of low back pain to pregnancy and gynecologic factors. Spine 1991;16:432-6. 30. Mantle MJ, Homers J, Currey HLF. Backache in pregnancy II: prophylactic influence of back care classes. Rheumatol Rehab 1981;20:227-32.

Address correspondenceand reprint requeststo Alyse Kelly-Jones,MD, University of Florida, Health Science Center at Jacksonville, Department of Obstetrics and Gynecology, 653-l West 8th Sfreet, Jacksonville, FL 32209-6511.

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