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Intensive dynamic back exercises for chronic low back pain: a clinical trial
Pain, 47 (1991) 53-63 a 1991 Elsevier Science Publishers ADONIS 0304395991001980
53 B.V. All rights reserved
0304-3959/91/$03.50
PAIN 01864
Intensive dynamic back exercises for chronic low back pain: a clinical trial * Claus Manniche, Eva Lundberg, Inge Christensen,
Lis Bentzen and Grete Hesselsoe
Department of Rheumatology, Herlec Hospital, Unicersity of Copenhagen, Copenhagen (Denmark) (Received
1 May 1990, revision
received
14 February
1991, accepted
1 March
19911
Summary
The effect of intensive dynamic back extensor exercises for patients with chronic low back pain was investigated in a controlled clinical trial in which chronic low back pain patients underwent a 3-month intensive training program with a total of 30 sessions. The 105 patients were divided into 3 groups: a treatment group, an alternative group which underwent l/5 of the treatment group’s exercise program per session, and an alternative group in which treatment consisted of thermotherapy, massage and mild exercise. Regardless of whether the treatment outcome is assessed qualitatively or quantitatively, a statistically significant, favorable difference was found between the results for the treatment group and for the alternative groups at conclusion and at the 3-month follow-up. It appeared from the quantitative assessment that patients in the treatment group who completed the training program at least once a week for the entire l-year follow-up period were the only patients with a significantly better back status after 1 year compared to the time of inclusion. Irrespective of sex, age, duration and degree of severity of back trouble, or of pre-existing sciatica or pathological findings upon X-ray of the spine, patients obtained a favorable result from the training program. The therapy was found to be without risk, but patients with clinical signs of current lumbar nerve root compression or radiological signs of spondylolysis or halisteresis of the spine were excluded from the study. Key words:
Low back pain; Back exercises; Clinical trial
Introduction
The cause of chronic low back pain in an individual patient is often elusive, and the diagnostic methods available are of limited value [38,46]. Correspondingly, specific and well-documented therapeutic offers are difficult to draw up, and the spontaneous remission rate of approximately 0.8 within a 3-month period for acute low back pain gives ample room for valuable methods of treatment as well as for those which are not of value.
* This study has received economic support from the Danish Research Council (12-74041 and from the Danish Health Foundation, Sygekassernes Helsefond (H 11/78-87). Correspondence to: Claus Manniche, M.D., Department of Medicine, Division of Rheumatology, Hvidovre Hospital, University of Copenhagen, DK-2650 Hvidovre, Denmark.
Of the numerous treatment principles which might be chosen for patients with low back pain, training therapy has occupied a central position for many years. Almost all back therapists have particularly regarded this active form of treatment as an indispensable basic element in the treatment attempt, although documentation of its benefical effect is scanty [12]. In the 1950s the use of dynamic flexion/extension training programs was described [11,451. Later, in the 1960s isometric exercise was more frequently but cautiously used. Interpretation of results from basic research made it reasonable to assume that by performing back exercises patients could avoid harmful disc strain if they used isometric instead of dynamic extension/ flexion exercises. After introduction of the Swedish back school, the essential emphasis of which is on light isometric exercise, these exercise principles became completely predominant [171. Two controlled studies 123,281 are often referred to as documentation for the effectivity of light isometric back exercises, as signifi-
cant difference is claimed between the randomized groups to the advantage of light isometric exercises. In Kcndal and Jenkin’s study, however, the statistical method is not accounted for, and Lidstriim and Zachrisson find no difference between the treatment group and one of the alternative groups. Accordingly, it is difficult to draw reliable conclusions from these studies [31]. Later, other controlled studies have had difficulty in proving any positive effect from either dynamic or isometric back exercises [ IO,?&5 11. During recent years, general exercise has been shown to have a positive influence on the nutrition of discs [20], and other studies have documented that being in good physical condition reduces the risk for occurrence of low back pain [7]. Likewise, new epidemiological data show concurrence between chronic low back trouble and weakened endurance of the back musculature [1,4,15,22,37], and the combination of a weak back and back-straining work increases the risk of development of back trouble 181. Changes in bone, muscle and neurophysiological conditions resulting in reduced back pain is also possible [9,16,43,44]. All these observations seem to indicate that specific training and maintenance of the musculature around the spine, with increased strength and endurance as the goal, can diminish the occurrence of low back pain. In all IikeIihood, it is primarily the dosage rather than the form of exercise that is of primary importance for the result. In recent years, several reports have appeared with good results using different forms of intensive back training 113,14,1t3,19124,36,40-421. The preventive effect of a training program against work-conditioned back pain has also been indicated [3,29]. On this basis, the authors have found it interesting to conduct a clinically controlled study in which highdosage and low-dosage back exercises were compared. The principles behind the training program described by 0feldt and Bfeldt [40] and Plum and Rehfeld [42] have formed the basis for the exercises employed for the study. Controlled studies of this sort present great methodological difficulties [6]. We followed the guidelines set out by Nachemson and Larocca [39]. Waddell [47] states that chronic low back disorders consist of 3 separate dimensions - pain, disability and physica impairment. We scored these dimensions separately on a new scale devised by C. Manniche called the Low Back Pain Rating Scale (RS) [32,34]. fA fuil version of this rating scale is available from C. Manniche upon request.) The total score of RS is used as effect parameter as well as the patient’s global assessment.
Al1 general practitioners in three Copenhagen municipalities received a written invitation to refer pa-
1’Al~l.E I
Chronic
low back pain at rest
icnd/or
in connection
with hach
strain of at least 0.5 year. Acute
low back pain for the third time or more frequently
within
the last half year. With or without sciatica flow back pain which extends to one/both legs). Age between
20 and 70 years, inclusive.
Radiological
examination
of lumbar spine at most 2 years.
Clinical signs of actual, recently developed anamnesis,
root pressure. (Suspect
+ positive Las?gue’s sign. + sensory loss/motor
paral-
ysis in lower limb.) Spondylolysis. Clinically verifiable Halisteresis
painful
hip arthrosis.
of the spine.
Known inflammation
of the joints.
Present or previous symptomatic logical diagnoses,
which
somatic disease or psycho-patho-
indicate
that the patient
will be found
unable to carry out the training. Lack of cooperation
Exclusion
ability.
after ranciomiznkm
I. Clinical sign of recently developed 2. Acutely
developed
root pressure.
somatic or psychiatric
disease so that training
cannot be carried out. 3. More
than 30% absenteism from training.
tients with chronic low back pain to the host department. Enclosed with the invitation were inclusion/ exclusion criteria for the study (‘I’able I). Of a total of 140 patients referred, 105 were entered consecutively after an interview and examination by a doctor to ensure that they fulfilled the inclusion criteria. The patients were informed that they would be entered into 1 of 3 groups at random by drawing lots, each group having a varied program of back exercises. Following this, they underwent data encoding in accordance with the Low Back Pain Rating Scale [32-341, consisting of the following elements: pain (O-30 points); disuhility questions about 15 everyday activities (O-30 points); and physical impairment - back endurance (O-10 points), Schober’s modified test (O-10 points), patients’ mobility (O- 10 points) and use of analgesics (O-10 points); fatal, U-100 points = RS. Data encoding was repeated after conclusion of treatment about 3 months Iater and again after 6 months. After 1 year, the patients responded to a postal RS which, however, only contained the dimensions of pain (O-30 points), disability (O-30 points), and use of analgesics (O-10 points). It was not possible to do other objective tests in the
55
TABLE II TREATMENT
IN THE THREE GROUPS
Group A, alternative treatment
Patients were treated with applications of hot compresses and massage of back and gluteal muscles in combination with a mild exercise program with mainly isometric exercises for the lumbar spine. 1. Prone, isometric back extension. 2. Supine crook-lying (knees flexed, feet flat on the couch), isometric abdominal contraction. 3. Supine crook-lying, sit up exercise. 4. Supine, maximal curl-up exercise, knees to shoulders. The four exercises were repeated 10 times. Treatment time was about 1 h. A total of 8 sessions were distributed over 1 month. Thereafter, there was no treatment for 2 months until control. Group B, modified back strengthening program
The 3 exercises are done in exactly the same way as in group C except that each exercise is repeated only 20 times. The dosage is thus l/S of that in group C. Treatment time totals 45 min. All other conditions in the training are identical with those in group C. Group C, intensive back strengthening program
1. Trunk lifting. Prone on a couch, hips at the edge, upper part of the body free but supported by the hands against the floor. Strap fixation over the calves. With hands on the forehead, the trunk is lifted to the greatest possible extension in hips and spine. If necessary, starting with support from physical therapist. During pauses, the patient is supported by a chair in front of the couch.
2. Leg lifting. Standing by the end of the couch, leaning over to a prone position with the hips against the edge in 90 o flexion, knees 45 o and feet on the floor. Strap fixation over the chest. Strap around knees to keep legs together. Both legs are straightened and lifted to the greatest possible extension in hips and spine. Again with support from physical therapist if necessary.
TABLE
11 tconlinucd)
3. Pull to neck. Sitting on a stool with the arms straight and abducted submaximal
Before
resistance,
over the head and hands grasping a weight
lever (pulley
starting the exercise program.
the patient
exercises is done in the sequence mentioned.
is offered
a hot back packing for the lower back for IS min. Following
is done 50 times, then the second exercise Sit times, and finally the third exercise Xl times. The training cycle is performed total of 30 sessions was given over a 3-month trained
in teams of 4-5,
period with 3 training
where 2 physical therapists
attended
the training
in the exercises and patients were helped in the last part of the movement
by themselves.
Movements
were not forced but were executed
The physical therapists realized
discomfort
Treatment
twice but interrupted time totals 1.5 h. A
with help and instructions.
Large movement
fluctuation
track as they were not at first able to mobilize strength
as guided active movement.
It was emphasized
that exercises be performed
at a
pace.
the lumbar region. However, The training
this, each of the 3
episodes a week for the first month and 2 a week for the next 2 months.
was attempted
dynamic but controlled
Against
Each exercise is done in a series of 10 attempts with 1 min rest between attempts. The first exercise
by rest with hot packing for 15 min. In this way, each of the 3 exercises is done 100 times in the back program. Participants
device).
the lever ia pulled down behind neck and shoulders.
that the exercises for many patients were associated with great strain and often elicited tension or pain over
if the exercises elicited or aggravated
sessions consistently ended with thorough
pain in the lower limbs, this was not accepted.
stretching
of the working
muscle groups in order to
relieve muscular tenderness
and
after the intensive training.
Prone and supine exercises were done on couches which could be elevated, where a strap with a pillow was used for fiation. region, a foam-rubber
pillow was used to avoid uncomfortable
couch. The weight lever exercise was performed with up to a 30 kg pull. Ordinarily,
women
increased strength. In the beginning, the physicafly demanding
pressure against the inguinal region, as well as to hinder forward
Under
the hip
sliding on the
with a pulley device with a transverse wooden bar of 130 cm. It was possible to load the exercise
trained
with 14-22
kg resistance
training was graduated
times: in the following sessions 60 times. etc., until during a maximum -
and men with 22-30
kg. The weight was increased
in pace with
in such a way that the patients at the first session did each of 3 exercises 50 course of 2 weeks. they were using the full training.
TABLE
III Characteristics
of the initial 105 patients
No
Median
lO/YO percentile
Personal data Age (years) Height (cm) Weight (kg) Low back pain duration (years) Sciatica duration (years) Previously disc-operated (years)
65 IO
4.5 170 67 15 Y 6
32- 57 160-182 55- 88 5- 34 2- 23 3- 10
X-ray findings Lumbar disc degeneration Lumbar spondylosis Lumbar disc degeneration Scheuermann’s disease Other abnormal findings Nothing abnormal
22 15 15 17 Y 27
+ spondylosis
Employment/reported A
Groups Employed at inclusion Employed but reported ill > 1 week/month due to back trouble at inclusion Reported ill > 1 week/month due to back trouble at conclusion Back straining job
ill for 90 patients
who completed
B
28/32
(88%)
4/32
(13%)
o/31
l/32 l5/28
(3%) (54%)
l/31 11/27
dimension ‘physical impairment’ because of the use of the postal follow-up method. All data collection was done blindly by the same observer who did not know to which group the patients
Points 70
the investigation C
27/31(87%)
22/27
(81%)
(0%)
3/27
(11%)
(3%) (41%)
2/27 13/22
(7%) (59%)
would be assigned. After data encoding, patients were allocated by a block randomization procedure to 1 of the 3 treatment groups (Table II). Treatment commenced shortly afterwards, and throughout the entire
GroupB (n = 29)
Points
Group C (ll = 27)
1
Points
.
&3-
30
.
I .
.
?
k
IO
.t
a
”
”
;
.
+
.
! t
‘i
I
-10 1
Fig. I. Low back pain rating
score and median. the 3-month
Point scoring
follow-up.
Group
before,
after and at 3-month
B: 2 patients
did not participate
follow-up.
Group
in the 3-month
A: 8 patients
follow-up.
did not participate
in
TAf3L.t: IV QUALITATIVE Patients
ASSESSMENT‘/AN/~l.YSlS
evaluation
qucncc the same 3 therapists wcrc in charge and sought to maintain a neutral attitude towards the trcatment. After 3months follow-up, for ethical reasons all patients, regardless of the primary randomization, were offered the opportunity to continue (once a week) or commence intensive back exercises in the form of evening classes according to the principles used in treatment group C.
:!
after treatment. Number
t%)
Responders Very satisfactory Satisfactory. little discomfort Non-responders Acceptable. some discomfort Unchanged Aggravated
For use as measurement of the improvement of intervention, patients underwent data encoding in accordance with RS and relative differences (Total before minus Total after) were calculated. The relative difference (delta Total) is regarded as the most impor-
‘, Using Fisher’s exact test: AB tP = 0.08, NS); AC (P = 0.00005); and BC (P = 0.05).
TABLE
V
QUANTITATIVE Median (10/90
ASSESSMENT/ANALYSfS. percentill
Delta total 1 Before treatment Delta total 2 Before treatment Delta total 3 Before treatment
SCALE
Group
minus after treatment
minus follow-up
minus l-year
LOW BACK PAIN RATING
3-month
f(~ilow-up
A
B
C
2.0
( - I1.7/19.5)
5.7 ( - 4.4/23.7)
14.7 t -3.2/29.4)
5.5 (- 12.8/19.5)
7.0
( - 1 l.tJ/21.51
15.0 (-X.4/31.4)
0.0
h.0
6.0
(- 1{).~/14.~)
(- 14.4/17.2)
(- 11.3/1Y.h)
AB
AC
BC
P < 0.05
P < 0.0001
P < 0.0
Group
delta Total I Mann-Whitney
I
ABC P < 0.0002 P < 0.0000
Kruskal-Wallis Jonckheere-Terpstra delta Total 2 * Mann-Whitney
NS t P < 0.43
P < 0.002 ABC P < O.OilS P cy 0.0005
P < 0.0 I
NS (P = 30)
NS(P=O.29) ABC NS (P = 0.47) NS (P = 0.2X)
NS
Kruskal-Wali~s J(~I~ckheere-Terpst~ delta Total 3 * Mann-Whitney Kruskal-Wallis Jonckheere-Terpstra Group
C: ?I continuous
+ trainingtn
training
in the 3-month
follow-up
and 7 patients
follow-up
0.3 f - 21.0/9.h) P = 0.005
did not participate
(P = 0.90)
- trainingtn
= 13)
Mann-Whitney * Ten patients
one-year
12.8 f - 4.6/26.4)
delta Total 3
1
in the I-year
follow-up.
= 13)
59
tant effect parameter (quantitative assessment). Also patient’s ‘global assessment’ is regarded as an effect parameter (qualitative assessment). Non-parametric statistical methods were employed in all cases, using the data program Medstat [50]. A 5% level of significance has been chosen in the study.
Min.
4l c-
A
_,_.-.-.-
,” = 13,
3-
2-
----___
-----
B(” = 29,
l-
00 0
Results A total of 105 patients .(64 women) were entered into the study. Patient characteristics and radiological findings are shown in Table III. Qualitative
assessment
On conclusion of the treatment, patients were requested to evaluate their back condition. Only the qualitative evaluations ‘very satisfactory’ and ‘satisfactory, little discomfort’ were considered as an acceptable outcome after a protracted and intensive treatment. Table IV shows that the results with group C are superior to both groups B and A. Quantitative
assessment
Total score by using RS in the 3 randomized groups before, after and at 3-month follow-up is shown in Fig. 1. The difference between RS scoring before start of treatment and after conclusion (delta Total 11, or RS scoring after 3-month follow-up (delta Total 2) or 1 year follow-up (delta Total 3), respectively, is shown in Table V. The matching statistics are in all instances statistically significant between the groups immediately after cessation of the treatment to the advantage of treatment group C. After 3-month follow-up, group C was still superior to both groups A and B. Thirteen of 27 patients primarily randomized to intensive exercises (group C> at their option continued the training at the hospital once a week during the entire follow-up period, whereas the rest of group C patients for various reasons did not carry through regular training during
6
3
Umonth
Fig. 2. Isometric endurance: groups A, B and C k continuous training at 1 year. Development in isometric muscle strength in patients in the randomized groups. Test method: The patient was placed on a couch with legs strapped and the trunk unsupported from the iliac crest. The time for which the patient could remain horizontal, clear of the floor, was recorded. If the patient could remain in the position for 270 set, the test was concluded.
the follow-up period. In the subgroup which continued the training (group C, + exercise) one also found after 1 year a significantly better training outcome than in the other part of the patients in group C (group C, exercise) and group A, and there was a favorable trend in comparison to group B (Table VI. By using Wilcoxon’s test, a statistically significantly changed score was disclosed from entrance to exit for pain, disability and physical impairment, as measured by use of rating scale in group C. A similar, although less pronounced, result was seen in group B. However, no statistically significant changes were seen in group A 1471. In the subgroup (group C, + exercise) which continued training during the follow-up period, at lyear follow-up there still was a significantly better rating of RS, whereas a significant difference was not found in the other treatment groups (Table VI). Fig. 2 shows the development in isometric muscle strength in the randomized groups. The influence of continued training on improvement in the disease dimensions ‘pain’ and ‘disability’ is illustrated in Fig. 3.
Points 15-I
TABLE VI
(ll = 13)
DIFFERENCES IN RATINGS AND AT l-YEAR FOLLOW-UP
BEFORE
RANDOMIZATION (n = 13)
Wilcoxon’s test: Total 1 minus Total 3. (tl = 13)
A
B
NS
(P = 0.45)
-
C
ffl = 13)
P = 0.045 f”p”= 0.08) C: -training NS (P = 0.76) C: + training
(P = 0.002)
I
3
I
3 months follow-up
1 year follow-up
tlmonth
Fig. 3. Pain and disability: group C+training at l-year follow-up. The influence of continued intensive exercises on improvement in the dimensions “pain” and “disability.”
Table VII shows the qualitative result when randomized groups are divided into subgroups with regard to the following characteristics: sex, age. duration of low back pain, degree of severity of back trouble. with or without sciatica and X-ray findings. In no instance
TABLE
VII
OUALITATIVE
RESULTS
IN SUB-GROUPS
Subgroup
OF THE POPULATION
Group
(no./f?)
A Gender Men Responders Non-responders Women Responders Non-responders Age group 20-39 years Responders Non-responders 40-49 years Responders Non-responders SO-70 years Responders Noun-res~nders Duration of low back pain 6 months to I year Responders Non-responders 2-s years Responders Non-responders h-60 years Responders Non-responders History of back trouble Severity Responders Non-responders C Severity * Responders N(~n-res~)nd~rs - Sciatica Responders Non-responders + Sciatica Responders Non-responders X-ray findings Lumbar spine. nothing abnormal Responders Non-responders Disc degeneration or spondylosis Responders Non-responders Scheuermann’s disease or other abnormal Responders N~lll-responders
* + Severity = (1) previously trouhlc
did these characteristics have a statistically significant influence on the qualitative treatment outcome. Scvcral of these subgroups. however, are very small. Scores on RS (delta Total 1) were strongly correlated to patients’ qualitative evaluation of treatment
and/or
B
C
6 (43C/r ) x (57%) 7 (41Ci,) 10 (59%)
-.---II--_
h m%) 2 (25%) 14 (74%) 5 (26%)
3 (50%) 4 (50%) .1 (27%) 8 (73%)
7 (47%) 8 6wi;) 2 (25%) 6 (75%)
2 (29%) 5 (713) 4 (22%) 14 (78%)
3 (17%) IS (Xx+)
12 (75%) 4 (25%)
h csX%) 10(62%i)
15 (75%) 5 (25%) 5 (71%) 2 (29%)
6 (7%) 2 (2w 1
I (11%) IO (X9~?) 4 (25%) 12 (75%) findings I ( 14”: ) 6 (86%)
4 (29% ) IO (71%)
3 (43%) 4 fs7e*)
Ii (73%) 4 (27V) 3 (7.5%)
i (2s)
undergone back surgery and/or (‘2) currently reported ill due to back trouble and/or (31 change of job due to back (4) early retirement due to hack trouble and/or (5) daily consumption of morphine or analogues due to back pain.
61
Discussion
TABLE Vtii Drop-outs
Side effects Aggravation of back pain + Aggravation of sciatica Other reasons Colon cancer diagnosed Not compatible with work Absence from treatment without reason Prolonged travel to home country Personal
A
B
1
1 2
1
1
C
1 1
1
outcome (Spearman (RHO) = 0.75) [33]. Twenty consecutive patients were asked to complete RS (Pain + Disability) a second time at home on the evening of the same day so as to measure short-time repeatability. The Spearman correlation coefficient between the 2 sets of scores was 0.99.
Drop-outs
Fifteen of the 105 patients included dropped out before conclusion of treatment (Table VIII). In most instances, this occurred shortly after commencement of treatment. In 6 cases distributed among all 3 randomized groups, patients dropped out because of aggravated back pain, in 3 cases accompanied by aggravated sciatic pain. No additional evidence of root compression was observed. Of the 90 patients who completed the trial treatment, 5 had positive Lasegues’ sign (radiation of pain in the leg on straight-leg raising) [25], and 5 had physical signs of root compression. At the conclusion, 4 patients had Lasegues’ sign and 5 had persistent physical signs of root compression. Two of the 10 patients who had previously undergone surgery on the disc dropped out of the trial treatment, in both instances due to aggravated low back pain. Two cases of subacromial and 1 case of trochanterian bursitis were observed, but in none of these cases was an exclusion necessary. Independent of the back exercises, 1 patient experienced acute sciatic pain during the follow-up period. Later this patient underwent surgery for a lumbar disc prolapse. No other side effects, somatic or psychological, were observed in connection with the trial treatment. The patients who dropped out are not included in the statistical tests. Inclusion of the 6 patients who dropped out due to side effects - on the intention-to-treat principle where these patients’ qualitative treatment outcome is rated as poorly as possible - does not change the statistical results.
In recognition of the fact that diagnostic possibilities in connection with chronic low back pain are very limited, the authors of this study have chosen to include all patients who fulfilled all the broadly chosen criteria mentioned in Table I. Excluded, however, are patients with radiological findings indicative of spondylolysis or halisteresis of the spine on the basis of recent X-ray examination. Likewise, patients with clinical signs of current root pressure are excluded after examination by a doctor. Exclusion of these patient groups is due to the hypothetical risk which exists for eliciting bone fracture of the spine or aggravation of root-pressure symptoms under intensive back training [5,21,27, 301. Based on the conditions concerning patient inclusion, we find that the population in the present study is essentially identical to a representative random sampling of the population with chronic low back pain in Copenhagen county [4,38,46]. The investigation was planned such that the patients were randomized into 3 groups. In group A, treatment consisted of thermotherapy, massage, and mild isometric exercises according to Williams [48] in a relatively short treatment series. Despite its being a resource-demanding treatment, the authors would only expect a poor possibility for durable inprovement of chronic low back pain. Group A, therefore, was regarded as a control group in which the spontaneous course of low back pain was registered. The outcome of the study, in which the registered point scores in this group (Table VI essentially stay on a constant level, seems to confirm this view. Group B was a modified back strengthening group, in which back muscle training was only l/5 of that in the treatment group. On the other hand, the form of exercises and duration of treatment were identical with that of the treatment group. The patients were under the impression that they were receiving intensive back training. The patients’ evaluation of a positive treatment outcome in 42% of the cases corresponds well with the anticipated placebo effect [26]. In the treatment group, massive treatment progress was registered, qualitatively assessed as 74%. Improvement of back pain can be found in all of the disease dimensions registered (Fig. 2, Fig. 3), and improvement is lasting at conclusion of the 3-month follow-up period. After 1 year follow-up, only patients who by their own choice continued the back training at least once a week had preserved the formerly obtained progress in point score after RS (Table VI and have generally a markedly better training result than other patients in the study (Table VI>. It is concluded that intensive back training can effect a lasting improvement of the
pain condition but that continued training is necessary to avoid relapse. One-year follow-up is contaminated by the fact that for ethical reasons many of the patients in groups A and B were allowed to break the primary randomization after 3 months of follow-up and started a longer intensive course of training. Therefore, many of these patients ‘raise’ the RS rating at l-year follow-up without improvement being considered to have resulted from the primary intervention. On the basis of the often insignificant results of previous back training studies [l&35,51] it is remarkable that this study shows such a pronounced difference between the randomized groups. In the opinion of the authors, part of the explanation is to be found in the fact that treatment duration has been such that the chosen treatment has been given a fair chance to have an effect on a chronic condition of often long duration. During the first 2-4 weeks of treatment many patients experienced increased discomfort from muscles (fatigue and tenderness) and continued back trouble. Not until the second or third month did a gradual improvement in the condition appear. To the authors, it has been surprising that so many patients were able to perform the intehsive back exercises without difficulty. Table VIII shows that even patients with a great degree of back trouble, without more drop outs than average, could complete the treatment program and benefit. Neither age nor existing sciatica seems to reduce the possibility for a beneficial effect from this form of treatment. In this study, the form of treatment has been tested as a whole. Thus, we are not able to demonstrate whether it is specifically the intensive back muscle training or, on the contrary, the use of h~erextension back exercises that yield the favorable result. Furthermore, we wish to better identify that group of patients who will benefit from the training and to exclude in advance those patients who can neither tolerate this form of treatment nor benefit from it. Further training studies are in preparation in order to elucidate these questions more closely. It is also possible that this form of treatment can be justified at the work place, where groups of employees with particularly back-straining work can build up their back strength through training to avoid back injuries. Since this treatment can advantageously be conducted in a group, the resources do not differ from that of other therapies for which treatment is often individual. The authors themselves have introduced this form of treatment at their hospital and, during the last year, have had very good experience with this also in daily practice. In accordance with theoretical considerations [2,31], we now include an abdominal muscle exercise as well as general physical training [37l and stretching exercises [49] in the training program.
aacrw 10 ,
I-
tmk
exerclee
(n = 1)
s-
Fig. 4. A typical pain diary for the 3-month course of intensive back exercises for a patient with chronic low back pain.
Many patients, including those outside this study, have obtained fine results, but it is important to keep in mind that the treatment trial must have a duration of several months before rest&s can be judged. After conclusion of the randomized investigation, several patients have kept a pain diary on the course of their pain experience in connection with starting a 13”week training program with 2 weekly sessions. Fig. 4 is a typical patient’s pain report and emphasizes that the treatment trial ought to have a duration of several months. The result of l-year follow-up shows clearly that intensive back training ought to continue in a longer and continuous course if a lasting result is desired. Therefore, it is im~rtant that facilities are created which invite patients to a continued course of training in larger groups, for example in health clubs, at the work place or in the form of evening classes. Some patients will be able to undertake the longer course of training in their own homes.
For the time being, intensive back training ought to be preceded by radiological examination of the spine as well as by clinical examination by a doctor. Patients with signs of acute lumbar root pressure, spondylolysis or halisteresis are excluded due to the h~otheti~al risk which exists for aggravation of root pressure or eliciting bone fracture. At the beginning of treatment, there should be 1 physical therapist for 2-3 patients. Here the basic instructions and rehabilitation take place. Any side effects can be noted in a satisfactory way and advice and guidance given when needed. After a couple of months, the training can be undertaken with less supervision in larger groups (8-10 patients).
Iieferences 1 Addison, R. and Schultz, A., Trunk strengths in patients seeking hospitalization for chronic low-back disorders, Spine, 6 (1980) 539-544.
63 2 Andersson, G., Ortengren, R. and Nachemson, A., Intradiscal pressure, intraabdominal pressure and myoelectric back muscle activity related to posture and loading, Clin. Orthop., 129 (1977) 156-162. 3 Bergquist-Ulman, M. and Larsson, U., Acute low back pain in industry. A controlled prospective study with special reference to therapy and confounding factors, Acta Orthop. Stand., Suppl. 170 (1977) 1-117. 4 Biering-Sorensen, F., Physical measurements as risk indicators for low-back trouble over a one-year period, Spine, 9 (1984) 106-119. 5 Biering-Sorensen, F., Rolsted, F., Schroll, M. and Runeborg, O., The relation of spinal X-ray to low-back pain and physical activity among 60-year-old men and women, Spine, 10 (1985) 445-451. 6 Bloch, R., Methodology in clinical back pain trials, Spine, 12 (1987) 430-432. 7 Cady, L.D., Bischoff, D.P.. O’Connell, E.R., Thomas, PC. and Allan, J.H., Strength and fitness and subsequent back injuries in firefighters, J. Occup. Med., 21 (1979) 269-272. 8 Chaffin, D.B., Human strength capability and low-back pain, J. Occup. Med., 16 (1974) 248-254. 9 Chow, R.K., Harrison, J.E., Brown, C.F. and Hajek, V., Physical fitness effect on bone mass in postmenopausal women, Arch. Phys. Med. Rehab., 67 (1986) 231-234. 10 Davies, J.E., Gibson, T. and Tester, L., The value of exercises in the treatment of low back pain, Rheum. Rehab., 18 (1979) 243-247. 11 De Lorme, T.L. and Watkins, A.L., Progressive Resistance Exercise. Appleton Century Crofts, New York, 1951, pp. 1-159. 12 Deyo, R.A., Conservative therapy for low back pain. Distinguishing useful from useless therapy, J. Am. Med. Assoc., 250 (1983) 1057-1062. 13 Deyo, R.A., Walsh, N.E., Martin, D.C., Schoenfeld, L.S. and Ramamurthy, S., A controlled trial of transcutaneous electrical nerve stimulation (TENS) and exercise for chronic low back pain, N. Engl. J. Med., 322 (1990) 1627-1634. 14 Dryssen, T., Svedenkrans, M. and Paasikivi, J., Muskeltrlning vid besvar i nacke och skuldror effektiv behandling for att minska smarten, Lakartidningen, 22 (1989) 2116-2120. 15 Editorial, Risk factor for back trouble, Lancet, i (1989) 1305-1306. 16 Fields, H.L., Sources of variability in sensation of pain, Pain, 33 (1988) 195-200. 17 Forssell, M.Z., The back school, Spine, 6 (1981) 104-106. 18 Hakipia, K., Javikoski, A., Mellin, G. and Hurri, H., Controlled study on the outcome of inpatient and outpatient treatment of low back pain. Part I, Stand. J. Rehab. Med., 21 (1989) 81-89. 19 Hazard, R.G., Fenwick, J.W., Kalisch, S.M., Redmond, J., Reeves, V., Reid, S. and Frymoyer, J.W., Functional restoration with behavioral support. A one-year prospective study of patients with chronic low-back pain, Spine, 14 (1989) 157-161. 20 Helm, S. and Nachemson, A., Variations in the nutrition of the canine intervertebral disc induced by motion, Spine, 8 (1983) 866-874. 21 Hutton, WC., Stott, J.R.R. and Cyron, B.M., Is spondylolysis a fatigue fracture?, Spine, 12 (1987) 202-209. 22 Jorgensen, K. and Nicolaisen, T., Trunk extensor endurance: determination and relation to low-back trouble, Ergonomics, 30 (1987) 259-267. 23 Kendall, P.H. and Jenkins, J.M.. Exercises or backhache: a double-blind controlled trial, Physiotherapy, 53 (1968) 154-157. 23 Klein, R.G., and Eek, B.C., Low-energy laser treatment and exercise for chronic low back pain; double-blind controlled trial, Arch. Phys. Med. Rehab., 71 (1990) 34-37. 25 Kosteljanetz, M., Bang, F. and Schmidt-Olsen, S., The clinical significance of straight-leg raising (Lasegue’s sign) in the diagnosis of prolapsed lumbar disc, Spine, 13 (1988) 393-395. 26 Leading article. Double-blind or not?, Br. Med. J., iii (1970) 597-598.
27 Libson, E., Bloom, R.A. and Dinari, G., Symptomatic and asymptomatic spondylolysis and spondylolistesis in young adults, Int. Orthop., 6 (1982) 259-262. 28 Lidstrdm, A. and Zachrisson, M., Physical therapy on low back pain and sciatica, Stand. J. Rehab. Med., 2 (1970) 37-42. 29 Linton, S.J., Bradley, L.A., Jensen, I., Spangfort, E. and Sundell, L., The secondary prevention of low back pain: a controlled study with follow-up, Pain, 36 (1989) 197-207. 30 Magora, A. and Schwartz, A., Relation between low back pain and X-ray changes. 4. Lysis and olistesis, Stand. J. Rehab. Med., 12 (1980) 47-52. 31 Manniche, C., Back exercises for patients with chronic low back pain (English summary), Ugeskr. Laeger, 151 (1989) 2009-2012. 32 Manniche, C., Hesselsoe, G., Bentzen, L., Christensen, I. and Lundberg, E., Clinical trial of intensive muscle training for chronic low back pain, Lancet, ii (1988) 1473-1476. 33 Manniche, C., Lundberg, E., Christensen, I., Hesselsoe, G. and Bentzen, L., Intensive dynamic back exercises for patients with chronic low back pain. A controlled investigation (English summary), Ugeskr. Laeger, 151 (1989) 2030-2034. 34 Manniche, C., Asmussen, K., Lauritsen, B. and Vinterberg, H., Low back pain rating scale. Validation of a tool for assessment of low back pain, in preparation. 35 Martin, P.R., Rose, M.J., Nichols, P.J.R., Russell, P.L. and Hughes, LG., Physiotherapy exercises for low back pain: process and clinical outcome, Rehab. Med., 8 (1986) 34-38. 36 Mayer, T.G., Gatchel, J., Kishiono, N. et al., Objective assessment of spine function following industrial injury. A prospective study with comparison group and one-year follow-up, Spine, 10 (1985) 482-493. 37 McNeill, T., Warwick, D., Andersson, G. and Schultz, A., Trunk strengths in attempted flexion, extension and lateral bending in healthy subjects and patients with low back disorders, Spine, 6 (1980) 529-538. 38 Nachemson, A., Work for all, Clin. Orthop. Rel. Res., 179 (1983) 77-85. 39 Nachemson, A. and Larocca, H., Editorial, Spine, 12 (1987) 427-429. 40 0feldt, T. and 0feldt, A., Intensive muscle treatment of back pain, Scot. J. Phys. Ed., 17 (1989) 15-16. 41 Peters, J.L. and Large, R.G., A randomised control trial evaluating in- and outpatient pain management programmes, Pain, 41 (1990) 283-293. 42 Plum, P. and Rehfeld, J.F., Muscular training for acute and chronic back pain, Lancet, i (1985) 453-454. 43 Porter, R.W., Adams, M.A. and Hutton, W.C., Physical activity and the strength of the lumbar spine, Spine, 14 (1989) 201-203. 44 Secher, N.H., Mizuno, M. and Saltin, B., Adaptation of skeletal muscles to training, Bull. Eur. Physiopathol. Respr., 20 (1984) 453-457. 45 Sparup, K.H., Late Prognosis in Lumbar Disc Herniation. Munksgaard, Copenhagen, 1960, pp. 1-162. 46 Vallfors, B., Acute, subacute and chronic low back pain: clinical symptoms, absenteeism and working environment, Stand. J Rehab. Med., Suppl. 11 (1985) l-98. 47 Waddell, G., Clinical assessment of lumbar impairment, Clin. Orthop. Rel. Res., 221 (1987) 110-120. 48 Williams, P.C., The Lumbosacral Spine. McGraw-Hill, New York, 1965, pp. l-95. 49 Williford, H.N., East, J.B., Smith, F.H. and Burry, L.A., Evaluation of warm-up for improvement in flexibility, Am. J. Sport Med., 14 (1986) 316-319. 50 Wulff, H.R. and Schlichting, P., Medstat (version 2.1). Astra Group A/S, Albertslund, Denmark, 1988. 51 Zylbergold, R.S. and Piper, M.C., Lumbar disc disease: comparative analysis of physical therapy treatments, Arch. Phys. Rehab., 62 (1981) 176-179.
53 B.V. All rights reserved
0304-3959/91/$03.50
PAIN 01864
Intensive dynamic back exercises for chronic low back pain: a clinical trial * Claus Manniche, Eva Lundberg, Inge Christensen,
Lis Bentzen and Grete Hesselsoe
Department of Rheumatology, Herlec Hospital, Unicersity of Copenhagen, Copenhagen (Denmark) (Received
1 May 1990, revision
received
14 February
1991, accepted
1 March
19911
Summary
The effect of intensive dynamic back extensor exercises for patients with chronic low back pain was investigated in a controlled clinical trial in which chronic low back pain patients underwent a 3-month intensive training program with a total of 30 sessions. The 105 patients were divided into 3 groups: a treatment group, an alternative group which underwent l/5 of the treatment group’s exercise program per session, and an alternative group in which treatment consisted of thermotherapy, massage and mild exercise. Regardless of whether the treatment outcome is assessed qualitatively or quantitatively, a statistically significant, favorable difference was found between the results for the treatment group and for the alternative groups at conclusion and at the 3-month follow-up. It appeared from the quantitative assessment that patients in the treatment group who completed the training program at least once a week for the entire l-year follow-up period were the only patients with a significantly better back status after 1 year compared to the time of inclusion. Irrespective of sex, age, duration and degree of severity of back trouble, or of pre-existing sciatica or pathological findings upon X-ray of the spine, patients obtained a favorable result from the training program. The therapy was found to be without risk, but patients with clinical signs of current lumbar nerve root compression or radiological signs of spondylolysis or halisteresis of the spine were excluded from the study. Key words:
Low back pain; Back exercises; Clinical trial
Introduction
The cause of chronic low back pain in an individual patient is often elusive, and the diagnostic methods available are of limited value [38,46]. Correspondingly, specific and well-documented therapeutic offers are difficult to draw up, and the spontaneous remission rate of approximately 0.8 within a 3-month period for acute low back pain gives ample room for valuable methods of treatment as well as for those which are not of value.
* This study has received economic support from the Danish Research Council (12-74041 and from the Danish Health Foundation, Sygekassernes Helsefond (H 11/78-87). Correspondence to: Claus Manniche, M.D., Department of Medicine, Division of Rheumatology, Hvidovre Hospital, University of Copenhagen, DK-2650 Hvidovre, Denmark.
Of the numerous treatment principles which might be chosen for patients with low back pain, training therapy has occupied a central position for many years. Almost all back therapists have particularly regarded this active form of treatment as an indispensable basic element in the treatment attempt, although documentation of its benefical effect is scanty [12]. In the 1950s the use of dynamic flexion/extension training programs was described [11,451. Later, in the 1960s isometric exercise was more frequently but cautiously used. Interpretation of results from basic research made it reasonable to assume that by performing back exercises patients could avoid harmful disc strain if they used isometric instead of dynamic extension/ flexion exercises. After introduction of the Swedish back school, the essential emphasis of which is on light isometric exercise, these exercise principles became completely predominant [171. Two controlled studies 123,281 are often referred to as documentation for the effectivity of light isometric back exercises, as signifi-
cant difference is claimed between the randomized groups to the advantage of light isometric exercises. In Kcndal and Jenkin’s study, however, the statistical method is not accounted for, and Lidstriim and Zachrisson find no difference between the treatment group and one of the alternative groups. Accordingly, it is difficult to draw reliable conclusions from these studies [31]. Later, other controlled studies have had difficulty in proving any positive effect from either dynamic or isometric back exercises [ IO,?&5 11. During recent years, general exercise has been shown to have a positive influence on the nutrition of discs [20], and other studies have documented that being in good physical condition reduces the risk for occurrence of low back pain [7]. Likewise, new epidemiological data show concurrence between chronic low back trouble and weakened endurance of the back musculature [1,4,15,22,37], and the combination of a weak back and back-straining work increases the risk of development of back trouble 181. Changes in bone, muscle and neurophysiological conditions resulting in reduced back pain is also possible [9,16,43,44]. All these observations seem to indicate that specific training and maintenance of the musculature around the spine, with increased strength and endurance as the goal, can diminish the occurrence of low back pain. In all IikeIihood, it is primarily the dosage rather than the form of exercise that is of primary importance for the result. In recent years, several reports have appeared with good results using different forms of intensive back training 113,14,1t3,19124,36,40-421. The preventive effect of a training program against work-conditioned back pain has also been indicated [3,29]. On this basis, the authors have found it interesting to conduct a clinically controlled study in which highdosage and low-dosage back exercises were compared. The principles behind the training program described by 0feldt and Bfeldt [40] and Plum and Rehfeld [42] have formed the basis for the exercises employed for the study. Controlled studies of this sort present great methodological difficulties [6]. We followed the guidelines set out by Nachemson and Larocca [39]. Waddell [47] states that chronic low back disorders consist of 3 separate dimensions - pain, disability and physica impairment. We scored these dimensions separately on a new scale devised by C. Manniche called the Low Back Pain Rating Scale (RS) [32,34]. fA fuil version of this rating scale is available from C. Manniche upon request.) The total score of RS is used as effect parameter as well as the patient’s global assessment.
Al1 general practitioners in three Copenhagen municipalities received a written invitation to refer pa-
1’Al~l.E I
Chronic
low back pain at rest
icnd/or
in connection
with hach
strain of at least 0.5 year. Acute
low back pain for the third time or more frequently
within
the last half year. With or without sciatica flow back pain which extends to one/both legs). Age between
20 and 70 years, inclusive.
Radiological
examination
of lumbar spine at most 2 years.
Clinical signs of actual, recently developed anamnesis,
root pressure. (Suspect
+ positive Las?gue’s sign. + sensory loss/motor
paral-
ysis in lower limb.) Spondylolysis. Clinically verifiable Halisteresis
painful
hip arthrosis.
of the spine.
Known inflammation
of the joints.
Present or previous symptomatic logical diagnoses,
which
somatic disease or psycho-patho-
indicate
that the patient
will be found
unable to carry out the training. Lack of cooperation
Exclusion
ability.
after ranciomiznkm
I. Clinical sign of recently developed 2. Acutely
developed
root pressure.
somatic or psychiatric
disease so that training
cannot be carried out. 3. More
than 30% absenteism from training.
tients with chronic low back pain to the host department. Enclosed with the invitation were inclusion/ exclusion criteria for the study (‘I’able I). Of a total of 140 patients referred, 105 were entered consecutively after an interview and examination by a doctor to ensure that they fulfilled the inclusion criteria. The patients were informed that they would be entered into 1 of 3 groups at random by drawing lots, each group having a varied program of back exercises. Following this, they underwent data encoding in accordance with the Low Back Pain Rating Scale [32-341, consisting of the following elements: pain (O-30 points); disuhility questions about 15 everyday activities (O-30 points); and physical impairment - back endurance (O-10 points), Schober’s modified test (O-10 points), patients’ mobility (O- 10 points) and use of analgesics (O-10 points); fatal, U-100 points = RS. Data encoding was repeated after conclusion of treatment about 3 months Iater and again after 6 months. After 1 year, the patients responded to a postal RS which, however, only contained the dimensions of pain (O-30 points), disability (O-30 points), and use of analgesics (O-10 points). It was not possible to do other objective tests in the
55
TABLE II TREATMENT
IN THE THREE GROUPS
Group A, alternative treatment
Patients were treated with applications of hot compresses and massage of back and gluteal muscles in combination with a mild exercise program with mainly isometric exercises for the lumbar spine. 1. Prone, isometric back extension. 2. Supine crook-lying (knees flexed, feet flat on the couch), isometric abdominal contraction. 3. Supine crook-lying, sit up exercise. 4. Supine, maximal curl-up exercise, knees to shoulders. The four exercises were repeated 10 times. Treatment time was about 1 h. A total of 8 sessions were distributed over 1 month. Thereafter, there was no treatment for 2 months until control. Group B, modified back strengthening program
The 3 exercises are done in exactly the same way as in group C except that each exercise is repeated only 20 times. The dosage is thus l/S of that in group C. Treatment time totals 45 min. All other conditions in the training are identical with those in group C. Group C, intensive back strengthening program
1. Trunk lifting. Prone on a couch, hips at the edge, upper part of the body free but supported by the hands against the floor. Strap fixation over the calves. With hands on the forehead, the trunk is lifted to the greatest possible extension in hips and spine. If necessary, starting with support from physical therapist. During pauses, the patient is supported by a chair in front of the couch.
2. Leg lifting. Standing by the end of the couch, leaning over to a prone position with the hips against the edge in 90 o flexion, knees 45 o and feet on the floor. Strap fixation over the chest. Strap around knees to keep legs together. Both legs are straightened and lifted to the greatest possible extension in hips and spine. Again with support from physical therapist if necessary.
TABLE
11 tconlinucd)
3. Pull to neck. Sitting on a stool with the arms straight and abducted submaximal
Before
resistance,
over the head and hands grasping a weight
lever (pulley
starting the exercise program.
the patient
exercises is done in the sequence mentioned.
is offered
a hot back packing for the lower back for IS min. Following
is done 50 times, then the second exercise Sit times, and finally the third exercise Xl times. The training cycle is performed total of 30 sessions was given over a 3-month trained
in teams of 4-5,
period with 3 training
where 2 physical therapists
attended
the training
in the exercises and patients were helped in the last part of the movement
by themselves.
Movements
were not forced but were executed
The physical therapists realized
discomfort
Treatment
twice but interrupted time totals 1.5 h. A
with help and instructions.
Large movement
fluctuation
track as they were not at first able to mobilize strength
as guided active movement.
It was emphasized
that exercises be performed
at a
pace.
the lumbar region. However, The training
this, each of the 3
episodes a week for the first month and 2 a week for the next 2 months.
was attempted
dynamic but controlled
Against
Each exercise is done in a series of 10 attempts with 1 min rest between attempts. The first exercise
by rest with hot packing for 15 min. In this way, each of the 3 exercises is done 100 times in the back program. Participants
device).
the lever ia pulled down behind neck and shoulders.
that the exercises for many patients were associated with great strain and often elicited tension or pain over
if the exercises elicited or aggravated
sessions consistently ended with thorough
pain in the lower limbs, this was not accepted.
stretching
of the working
muscle groups in order to
relieve muscular tenderness
and
after the intensive training.
Prone and supine exercises were done on couches which could be elevated, where a strap with a pillow was used for fiation. region, a foam-rubber
pillow was used to avoid uncomfortable
couch. The weight lever exercise was performed with up to a 30 kg pull. Ordinarily,
women
increased strength. In the beginning, the physicafly demanding
pressure against the inguinal region, as well as to hinder forward
Under
the hip
sliding on the
with a pulley device with a transverse wooden bar of 130 cm. It was possible to load the exercise
trained
with 14-22
kg resistance
training was graduated
times: in the following sessions 60 times. etc., until during a maximum -
and men with 22-30
kg. The weight was increased
in pace with
in such a way that the patients at the first session did each of 3 exercises 50 course of 2 weeks. they were using the full training.
TABLE
III Characteristics
of the initial 105 patients
No
Median
lO/YO percentile
Personal data Age (years) Height (cm) Weight (kg) Low back pain duration (years) Sciatica duration (years) Previously disc-operated (years)
65 IO
4.5 170 67 15 Y 6
32- 57 160-182 55- 88 5- 34 2- 23 3- 10
X-ray findings Lumbar disc degeneration Lumbar spondylosis Lumbar disc degeneration Scheuermann’s disease Other abnormal findings Nothing abnormal
22 15 15 17 Y 27
+ spondylosis
Employment/reported A
Groups Employed at inclusion Employed but reported ill > 1 week/month due to back trouble at inclusion Reported ill > 1 week/month due to back trouble at conclusion Back straining job
ill for 90 patients
who completed
B
28/32
(88%)
4/32
(13%)
o/31
l/32 l5/28
(3%) (54%)
l/31 11/27
dimension ‘physical impairment’ because of the use of the postal follow-up method. All data collection was done blindly by the same observer who did not know to which group the patients
Points 70
the investigation C
27/31(87%)
22/27
(81%)
(0%)
3/27
(11%)
(3%) (41%)
2/27 13/22
(7%) (59%)
would be assigned. After data encoding, patients were allocated by a block randomization procedure to 1 of the 3 treatment groups (Table II). Treatment commenced shortly afterwards, and throughout the entire
GroupB (n = 29)
Points
Group C (ll = 27)
1
Points
.
&3-
30
.
I .
.
?
k
IO
.t
a
”
”
;
.
+
.
! t
‘i
I
-10 1
Fig. I. Low back pain rating
score and median. the 3-month
Point scoring
follow-up.
Group
before,
after and at 3-month
B: 2 patients
did not participate
follow-up.
Group
in the 3-month
A: 8 patients
follow-up.
did not participate
in
TAf3L.t: IV QUALITATIVE Patients
ASSESSMENT‘/AN/~l.YSlS
evaluation
qucncc the same 3 therapists wcrc in charge and sought to maintain a neutral attitude towards the trcatment. After 3months follow-up, for ethical reasons all patients, regardless of the primary randomization, were offered the opportunity to continue (once a week) or commence intensive back exercises in the form of evening classes according to the principles used in treatment group C.
:!
after treatment. Number
t%)
Responders Very satisfactory Satisfactory. little discomfort Non-responders Acceptable. some discomfort Unchanged Aggravated
For use as measurement of the improvement of intervention, patients underwent data encoding in accordance with RS and relative differences (Total before minus Total after) were calculated. The relative difference (delta Total) is regarded as the most impor-
‘, Using Fisher’s exact test: AB tP = 0.08, NS); AC (P = 0.00005); and BC (P = 0.05).
TABLE
V
QUANTITATIVE Median (10/90
ASSESSMENT/ANALYSfS. percentill
Delta total 1 Before treatment Delta total 2 Before treatment Delta total 3 Before treatment
SCALE
Group
minus after treatment
minus follow-up
minus l-year
LOW BACK PAIN RATING
3-month
f(~ilow-up
A
B
C
2.0
( - I1.7/19.5)
5.7 ( - 4.4/23.7)
14.7 t -3.2/29.4)
5.5 (- 12.8/19.5)
7.0
( - 1 l.tJ/21.51
15.0 (-X.4/31.4)
0.0
h.0
6.0
(- 1{).~/14.~)
(- 14.4/17.2)
(- 11.3/1Y.h)
AB
AC
BC
P < 0.05
P < 0.0001
P < 0.0
Group
delta Total I Mann-Whitney
I
ABC P < 0.0002 P < 0.0000
Kruskal-Wallis Jonckheere-Terpstra delta Total 2 * Mann-Whitney
NS t P < 0.43
P < 0.002 ABC P < O.OilS P cy 0.0005
P < 0.0 I
NS (P = 30)
NS(P=O.29) ABC NS (P = 0.47) NS (P = 0.2X)
NS
Kruskal-Wali~s J(~I~ckheere-Terpst~ delta Total 3 * Mann-Whitney Kruskal-Wallis Jonckheere-Terpstra Group
C: ?I continuous
+ trainingtn
training
in the 3-month
follow-up
and 7 patients
follow-up
0.3 f - 21.0/9.h) P = 0.005
did not participate
(P = 0.90)
- trainingtn
= 13)
Mann-Whitney * Ten patients
one-year
12.8 f - 4.6/26.4)
delta Total 3
1
in the I-year
follow-up.
= 13)
59
tant effect parameter (quantitative assessment). Also patient’s ‘global assessment’ is regarded as an effect parameter (qualitative assessment). Non-parametric statistical methods were employed in all cases, using the data program Medstat [50]. A 5% level of significance has been chosen in the study.
Min.
4l c-
A
_,_.-.-.-
,” = 13,
3-
2-
----___
-----
B(” = 29,
l-
00 0
Results A total of 105 patients .(64 women) were entered into the study. Patient characteristics and radiological findings are shown in Table III. Qualitative
assessment
On conclusion of the treatment, patients were requested to evaluate their back condition. Only the qualitative evaluations ‘very satisfactory’ and ‘satisfactory, little discomfort’ were considered as an acceptable outcome after a protracted and intensive treatment. Table IV shows that the results with group C are superior to both groups B and A. Quantitative
assessment
Total score by using RS in the 3 randomized groups before, after and at 3-month follow-up is shown in Fig. 1. The difference between RS scoring before start of treatment and after conclusion (delta Total 11, or RS scoring after 3-month follow-up (delta Total 2) or 1 year follow-up (delta Total 3), respectively, is shown in Table V. The matching statistics are in all instances statistically significant between the groups immediately after cessation of the treatment to the advantage of treatment group C. After 3-month follow-up, group C was still superior to both groups A and B. Thirteen of 27 patients primarily randomized to intensive exercises (group C> at their option continued the training at the hospital once a week during the entire follow-up period, whereas the rest of group C patients for various reasons did not carry through regular training during
6
3
Umonth
Fig. 2. Isometric endurance: groups A, B and C k continuous training at 1 year. Development in isometric muscle strength in patients in the randomized groups. Test method: The patient was placed on a couch with legs strapped and the trunk unsupported from the iliac crest. The time for which the patient could remain horizontal, clear of the floor, was recorded. If the patient could remain in the position for 270 set, the test was concluded.
the follow-up period. In the subgroup which continued the training (group C, + exercise) one also found after 1 year a significantly better training outcome than in the other part of the patients in group C (group C, exercise) and group A, and there was a favorable trend in comparison to group B (Table VI. By using Wilcoxon’s test, a statistically significantly changed score was disclosed from entrance to exit for pain, disability and physical impairment, as measured by use of rating scale in group C. A similar, although less pronounced, result was seen in group B. However, no statistically significant changes were seen in group A 1471. In the subgroup (group C, + exercise) which continued training during the follow-up period, at lyear follow-up there still was a significantly better rating of RS, whereas a significant difference was not found in the other treatment groups (Table VI). Fig. 2 shows the development in isometric muscle strength in the randomized groups. The influence of continued training on improvement in the disease dimensions ‘pain’ and ‘disability’ is illustrated in Fig. 3.
Points 15-I
TABLE VI
(ll = 13)
DIFFERENCES IN RATINGS AND AT l-YEAR FOLLOW-UP
BEFORE
RANDOMIZATION (n = 13)
Wilcoxon’s test: Total 1 minus Total 3. (tl = 13)
A
B
NS
(P = 0.45)
-
C
ffl = 13)
P = 0.045 f”p”= 0.08) C: -training NS (P = 0.76) C: + training
(P = 0.002)
I
3
I
3 months follow-up
1 year follow-up
tlmonth
Fig. 3. Pain and disability: group C+training at l-year follow-up. The influence of continued intensive exercises on improvement in the dimensions “pain” and “disability.”
Table VII shows the qualitative result when randomized groups are divided into subgroups with regard to the following characteristics: sex, age. duration of low back pain, degree of severity of back trouble. with or without sciatica and X-ray findings. In no instance
TABLE
VII
OUALITATIVE
RESULTS
IN SUB-GROUPS
Subgroup
OF THE POPULATION
Group
(no./f?)
A Gender Men Responders Non-responders Women Responders Non-responders Age group 20-39 years Responders Non-responders 40-49 years Responders Non-responders SO-70 years Responders Noun-res~nders Duration of low back pain 6 months to I year Responders Non-responders 2-s years Responders Non-responders h-60 years Responders Non-responders History of back trouble Severity Responders Non-responders C Severity * Responders N(~n-res~)nd~rs - Sciatica Responders Non-responders + Sciatica Responders Non-responders X-ray findings Lumbar spine. nothing abnormal Responders Non-responders Disc degeneration or spondylosis Responders Non-responders Scheuermann’s disease or other abnormal Responders N~lll-responders
* + Severity = (1) previously trouhlc
did these characteristics have a statistically significant influence on the qualitative treatment outcome. Scvcral of these subgroups. however, are very small. Scores on RS (delta Total 1) were strongly correlated to patients’ qualitative evaluation of treatment
and/or
B
C
6 (43C/r ) x (57%) 7 (41Ci,) 10 (59%)
-.---II--_
h m%) 2 (25%) 14 (74%) 5 (26%)
3 (50%) 4 (50%) .1 (27%) 8 (73%)
7 (47%) 8 6wi;) 2 (25%) 6 (75%)
2 (29%) 5 (713) 4 (22%) 14 (78%)
3 (17%) IS (Xx+)
12 (75%) 4 (25%)
h csX%) 10(62%i)
15 (75%) 5 (25%) 5 (71%) 2 (29%)
6 (7%) 2 (2w 1
I (11%) IO (X9~?) 4 (25%) 12 (75%) findings I ( 14”: ) 6 (86%)
4 (29% ) IO (71%)
3 (43%) 4 fs7e*)
Ii (73%) 4 (27V) 3 (7.5%)
i (2s)
undergone back surgery and/or (‘2) currently reported ill due to back trouble and/or (31 change of job due to back (4) early retirement due to hack trouble and/or (5) daily consumption of morphine or analogues due to back pain.
61
Discussion
TABLE Vtii Drop-outs
Side effects Aggravation of back pain + Aggravation of sciatica Other reasons Colon cancer diagnosed Not compatible with work Absence from treatment without reason Prolonged travel to home country Personal
A
B
1
1 2
1
1
C
1 1
1
outcome (Spearman (RHO) = 0.75) [33]. Twenty consecutive patients were asked to complete RS (Pain + Disability) a second time at home on the evening of the same day so as to measure short-time repeatability. The Spearman correlation coefficient between the 2 sets of scores was 0.99.
Drop-outs
Fifteen of the 105 patients included dropped out before conclusion of treatment (Table VIII). In most instances, this occurred shortly after commencement of treatment. In 6 cases distributed among all 3 randomized groups, patients dropped out because of aggravated back pain, in 3 cases accompanied by aggravated sciatic pain. No additional evidence of root compression was observed. Of the 90 patients who completed the trial treatment, 5 had positive Lasegues’ sign (radiation of pain in the leg on straight-leg raising) [25], and 5 had physical signs of root compression. At the conclusion, 4 patients had Lasegues’ sign and 5 had persistent physical signs of root compression. Two of the 10 patients who had previously undergone surgery on the disc dropped out of the trial treatment, in both instances due to aggravated low back pain. Two cases of subacromial and 1 case of trochanterian bursitis were observed, but in none of these cases was an exclusion necessary. Independent of the back exercises, 1 patient experienced acute sciatic pain during the follow-up period. Later this patient underwent surgery for a lumbar disc prolapse. No other side effects, somatic or psychological, were observed in connection with the trial treatment. The patients who dropped out are not included in the statistical tests. Inclusion of the 6 patients who dropped out due to side effects - on the intention-to-treat principle where these patients’ qualitative treatment outcome is rated as poorly as possible - does not change the statistical results.
In recognition of the fact that diagnostic possibilities in connection with chronic low back pain are very limited, the authors of this study have chosen to include all patients who fulfilled all the broadly chosen criteria mentioned in Table I. Excluded, however, are patients with radiological findings indicative of spondylolysis or halisteresis of the spine on the basis of recent X-ray examination. Likewise, patients with clinical signs of current root pressure are excluded after examination by a doctor. Exclusion of these patient groups is due to the hypothetical risk which exists for eliciting bone fracture of the spine or aggravation of root-pressure symptoms under intensive back training [5,21,27, 301. Based on the conditions concerning patient inclusion, we find that the population in the present study is essentially identical to a representative random sampling of the population with chronic low back pain in Copenhagen county [4,38,46]. The investigation was planned such that the patients were randomized into 3 groups. In group A, treatment consisted of thermotherapy, massage, and mild isometric exercises according to Williams [48] in a relatively short treatment series. Despite its being a resource-demanding treatment, the authors would only expect a poor possibility for durable inprovement of chronic low back pain. Group A, therefore, was regarded as a control group in which the spontaneous course of low back pain was registered. The outcome of the study, in which the registered point scores in this group (Table VI essentially stay on a constant level, seems to confirm this view. Group B was a modified back strengthening group, in which back muscle training was only l/5 of that in the treatment group. On the other hand, the form of exercises and duration of treatment were identical with that of the treatment group. The patients were under the impression that they were receiving intensive back training. The patients’ evaluation of a positive treatment outcome in 42% of the cases corresponds well with the anticipated placebo effect [26]. In the treatment group, massive treatment progress was registered, qualitatively assessed as 74%. Improvement of back pain can be found in all of the disease dimensions registered (Fig. 2, Fig. 3), and improvement is lasting at conclusion of the 3-month follow-up period. After 1 year follow-up, only patients who by their own choice continued the back training at least once a week had preserved the formerly obtained progress in point score after RS (Table VI and have generally a markedly better training result than other patients in the study (Table VI>. It is concluded that intensive back training can effect a lasting improvement of the
pain condition but that continued training is necessary to avoid relapse. One-year follow-up is contaminated by the fact that for ethical reasons many of the patients in groups A and B were allowed to break the primary randomization after 3 months of follow-up and started a longer intensive course of training. Therefore, many of these patients ‘raise’ the RS rating at l-year follow-up without improvement being considered to have resulted from the primary intervention. On the basis of the often insignificant results of previous back training studies [l&35,51] it is remarkable that this study shows such a pronounced difference between the randomized groups. In the opinion of the authors, part of the explanation is to be found in the fact that treatment duration has been such that the chosen treatment has been given a fair chance to have an effect on a chronic condition of often long duration. During the first 2-4 weeks of treatment many patients experienced increased discomfort from muscles (fatigue and tenderness) and continued back trouble. Not until the second or third month did a gradual improvement in the condition appear. To the authors, it has been surprising that so many patients were able to perform the intehsive back exercises without difficulty. Table VIII shows that even patients with a great degree of back trouble, without more drop outs than average, could complete the treatment program and benefit. Neither age nor existing sciatica seems to reduce the possibility for a beneficial effect from this form of treatment. In this study, the form of treatment has been tested as a whole. Thus, we are not able to demonstrate whether it is specifically the intensive back muscle training or, on the contrary, the use of h~erextension back exercises that yield the favorable result. Furthermore, we wish to better identify that group of patients who will benefit from the training and to exclude in advance those patients who can neither tolerate this form of treatment nor benefit from it. Further training studies are in preparation in order to elucidate these questions more closely. It is also possible that this form of treatment can be justified at the work place, where groups of employees with particularly back-straining work can build up their back strength through training to avoid back injuries. Since this treatment can advantageously be conducted in a group, the resources do not differ from that of other therapies for which treatment is often individual. The authors themselves have introduced this form of treatment at their hospital and, during the last year, have had very good experience with this also in daily practice. In accordance with theoretical considerations [2,31], we now include an abdominal muscle exercise as well as general physical training [37l and stretching exercises [49] in the training program.
aacrw 10 ,
I-
tmk
exerclee
(n = 1)
s-
Fig. 4. A typical pain diary for the 3-month course of intensive back exercises for a patient with chronic low back pain.
Many patients, including those outside this study, have obtained fine results, but it is important to keep in mind that the treatment trial must have a duration of several months before rest&s can be judged. After conclusion of the randomized investigation, several patients have kept a pain diary on the course of their pain experience in connection with starting a 13”week training program with 2 weekly sessions. Fig. 4 is a typical patient’s pain report and emphasizes that the treatment trial ought to have a duration of several months. The result of l-year follow-up shows clearly that intensive back training ought to continue in a longer and continuous course if a lasting result is desired. Therefore, it is im~rtant that facilities are created which invite patients to a continued course of training in larger groups, for example in health clubs, at the work place or in the form of evening classes. Some patients will be able to undertake the longer course of training in their own homes.
For the time being, intensive back training ought to be preceded by radiological examination of the spine as well as by clinical examination by a doctor. Patients with signs of acute lumbar root pressure, spondylolysis or halisteresis are excluded due to the h~otheti~al risk which exists for aggravation of root pressure or eliciting bone fracture. At the beginning of treatment, there should be 1 physical therapist for 2-3 patients. Here the basic instructions and rehabilitation take place. Any side effects can be noted in a satisfactory way and advice and guidance given when needed. After a couple of months, the training can be undertaken with less supervision in larger groups (8-10 patients).
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