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PubMed1995

Spectral electromyographic assessment of back muscles in patients with low back pain undergoing rehabilitation.

STUDY DESIGN: A surface electromyographic procedure for evaluating back muscle impairment was studied in patients undergoing rehabilitation for low back pain. OBJECTIVES: The results were analyzed to determine whether the electromyographic procedure was able to: 1) distinguish muscle impairment between patients with low back pain and normal subjects, and 2) monitor changes in muscle function after low back pain rehabilitation. METHODS: Patients with chronic low back pain (n = 85) were tested to measure the median frequency of the electromyographic signals from six lumbar electrode sites during sustained trunk extensions. A subset (n = 28) of these patients was re-tested after low back pain rehabilitation. A discriminant function for classifying subjects into "low back pain" and "normal" groups was formulated using the electromyographic data from a subset of the patients with low back pain (n = 28) and a normative sample (n = 42). Results for this "learning" sample were compared with results using the same function on the remaining "holdout" sample of patients (n = 57) and an additional normative sample (n = 6). Differences in electromyographic parameters before and after rehabilitation also were analyzed. RESULTS: The discriminant function classified subjects into low back pain and normal groups, with 86% and 89% correct classification for the "learning" and "holdout" samples, respectively. These classification results were independent of trunk extensor strength. Changes in median frequency after the rehabilitation program were consistent with improvements in back muscle fatigability. CONCLUSION: These findings demonstrate how electromyographic spectral measurements may be used to identify and monitor back muscle impairment in patients undergoing rehabilitation for low back pain.

Adult↗
PubMed1998

Low back pain in college athletes. A prospective study correlating lower extremity overuse or acquired ligamentous laxity with low back pain.

STUDY DESIGN: A prospective evaluation of the incidence of low back pain in college athletes was undertaken. OBJECTIVES: To evaluate prospectively leg length discrepancy, hip flexor tightness, and lower extremity acquired laxity or overuse as predictive factors for low back pain in college athletes. SUMMARY OF BACKGROUND DATA: A pilot study found an association between low back pain and the factors to be studied. Several allusions to the kinetic chain theory appear in the literature, but little prospective research has been done in examining the effects of lower extremity involvement on the back. METHODS: Two-hundred fifty-seven college athletes representing nine varsity sports were screened during a preseason sports physical examination. Measures of flexibility, ligamentous stability, leg length discrepancy, and overuse syndromes were recorded. Athletes were observed throughout the ensuing year for low back pain requiring treatment by the athletic trainer. Those athletes with low back pain as the result of direct trauma to the region were excluded from the data. RESULTS: Twenty-four athletes (9.3%) received treatment for low back pain. Thirteen of 87 women (15%) compared with 11 of 170 men (6%) required treatment for low back pain (P = 0.048). Of 57 athletes with lower extremity acquired laxity or overuse, low back pain developed in 14 (P < 0.001). CONCLUSIONS: Athletes with lower extremity acquired ligamentous laxity or overuse may be at risk for the development of noncontact low back pain during athletic competition. Female athletes with lower extremity involvement appeared to have a higher incidence of low back pain treatment compared with their male counterparts. Inflexibility of the lower extremities or leg length discrepancy were not associated with future low back pain treatment.

Adult↗
PubMed2001

2001 Volvo Award Winner in Clinical Studies: Effects of a media campaign on back pain beliefs and its potential influence on management of low back pain in general practice.

STUDY DESIGN: Quasi-experimental, nonrandomized, nonequivalent, parallel group-controlled study involving before and after telephone surveys of the general population and postal surveys of general practitioners was conducted, with an adjacent state used as a control group. OBJECTIVES: To evaluate the effectiveness of a population-based intervention designed to alter beliefs about back pain, influence medical management, and reduce disability and workers' compensation-related costs. SUMMARY OF BACKGROUND DATA: A multimedia campaign begun during 1997 in Victoria, Australia, positively advised patients with back pain to stay active and exercise, not to rest for prolonged periods, and to remain at work. METHODS: The campaign's impact on population beliefs about back pain and fear-avoidance beliefs was measured in telephone surveys, and the effect of the campaign on the potential management of low back pain by general practitioners was assessed by eliciting their likely approach to two hypothetical scenarios in mailed surveys. Demographically identical population groups in Victoria and the control state, New South Wales, were surveyed at three times: before, during, and after intervention in Victoria. RESULTS: The studies were completed by 4730 individuals in the general population and 2556 general practitioners. There were large statistically significant improvements in back pain beliefs over time in Victoria (mean scores on the Back Beliefs Questionnaire, 26.5, 28.4, and 29.7), but not in New South Wales (26.3, 26.2, and 26.3, respectively). Among those who reported back pain during the previous year, fear-avoidance beliefs about physical activity improved significantly in Victoria (mean scores on the Fear-Avoidance Beliefs Questionnaire for physical activity, 14, 12.5, and 11.6), but not in New South Wales (13.3, 13.6, and 12.7, respectively). General practitioners in Victoria reported significant improvements over time in beliefs about back pain management, as compared with their interstate colleagues. There were statistically significant interactions between state and time for 7 of 10 responses on management of acute low back pain, and for 6 of 10 responses on management of subacute low back pain. CONCLUSION: A population-based strategy of providing positive messages about back pain improves the beliefs of the general population and general practitioners about back pain and appears to influence medical management.

Australia↗
PubMed2005

Spinal cord stimulation for chronic back and leg pain and failed back surgery syndrome: a systematic review and analysis of prognostic factors.

STUDY DESIGN: Systematic review. OBJECTIVES: To assess efficacy and safety of spinal cord stimulation in patients with chronic leg and back pain and failed back surgery syndrome and to examine prognostic factors that predict spinal cord stimulation outcome. SUMMARY OF BACKGROUND DATA: A previous systematic review of spinal cord stimulation in patients with chronic back and leg pain and failed back surgery syndrome by Turner et al in 1995 identified 39 case studies and no controlled studies. METHODS: A number of electronic databases were searched through January 2002. Citation searching of included papers was undertaken, and gray literature was sought through contact with clinical experts. No language restrictions were applied. All controlled and noncontrolled study designs were included. Study selection was carried out independently by two reviewers. Prognostic factors (age, sex, duration of pain, time post surgery, follow-up duration, publication year, data collection year, indication, data collection country, study setting, and quality score) responsible for pain relief outcome across case series were examined using univariate and multivariate metaregression. RESULTS: One randomized controlled trial, one cohort study, and 72 case studies were included. The randomized controlled trial reported a significant benefit (P = 0.047) in the proportion of patients with failed back surgery syndrome reporting 50% or more pain relief with spinal cord stimulation (37.5%) compared with patients undergoing back reoperation (11.5%). There was evidence of substantial statistical heterogeneity (P < 0.0001) in the level of pain relief following spinal cord stimulation reported across case series studies. The four principal prognostic factors found to be predictive of increased level of pain relief with spinal cord stimulation were poor study quality score, short follow-up duration, multicenter (versus single center) studies, and the inclusion of patients with failed back surgery syndrome (versus chronic back and leg pain). Overall, 43% of patients with chronic back and leg pain/failed back surgery syndrome experienced one or more complications following a spinal cord stimulation implant, although no major adverse events were reported. CONCLUSIONS: Despite an increase in the number of studies over the last 10 years, the level of evidence for the efficacy of spinal cord stimulation in chronic back and leg pain/failed back surgery syndrome remains "moderate." Prognostic factors found to be predictive of the level of pain relief following spinal cord stimulation were study quality, follow-up duration, study setting, and patient indication.

Back Pain↗
PubMed1989

[Back exercises for patients with chronic low back pain].

The training therapy, which most back therapists consider an indispensable basic element in attempts to treat chronic low back pain, is reviewed, with an historical survey and description of the basic research in the field. Epidemiological studies show concurrence between chronic low back pain and reduced endurance of the back musculature and that the combination of a weak back and a back-straining occupation greatly increases the risk of low back trouble. On the basis of these studies, it is concluded that use of isometric back exercises in low dosage, which are central to the internationally acknowledged Swedish back school, only results in strengthening and increased endurance of the back muscles with difficulty. The author recommends introduction of intensive dynamic back extensor exercises which result in strength and endurance of the muscles. The back muscle training ought to be lifelong; thus, the exercises must be simple, learned over a longer period of time, so that the patients perceive the training as a natural and necessary part of everyday life.

Back Pain↗
PubMed2000

Massage for low back pain.

BACKGROUND: Low back pain is one of the most common and costly musculoskeletal problems in modern societies. Proponents of massage therapy claim it can minimize pain and disability, and speed return to normal function. OBJECTIVES: To assess the effects of massage therapy for non-specific low back pain. SEARCH STRATEGY: We searched Medline, Embase, Cochrane Controlled Trials Register, Healthstar, CINAHL and Dissertation abstracts from 1966 to 1999 with no language restrictions. References in the included studies and in reviews of the literature were also screened. Contact with content experts and massage associations were also made. SELECTION CRITERIA: This review included randomized, quasi-randomized or controlled clinical trials that investigated the use of any type of massage (using the hands or a mechanical device) as a treatment for nonspecific low back pain. DATA COLLECTION AND ANALYSIS: One reviewer applied the selection criteria and extracted the data. Two reviewers (one blinded to authors, institutions and journals) independently assessed the quality of each trial. A qualitative analysis (best-evidence synthesis) was performed due to clinical heterogeneity among the included trials and insufficient data reported. MAIN RESULTS: Four randomized controlled trials met the inclusion criteria. Two trials were of high and two of low methodological quality. None evaluated massage as the main intervention. Rather, it was the control intervention in studies evaluating manipulation, electrical stimulation, and a lumbar corset. There is limited evidence showing that massage is less effective than manipulation immediately after the first session and moderate evidence showing it is less effective than TENS during the course of sessions in relieving pain and improving activity. At the completion of treatment and at 3 weeks after discharge there is no difference among massage and manipulation, electrical stimulation or corsets, but this evidence is limited. REVIEWER'S CONCLUSIONS: Based on the studies reviewed, there is insufficient evidence to recommend massage as a stand-alone treatment for non-specific low back pain. There is a need for high quality controlled trials to further evaluate the effects of massage for this condition.

Adult↗
PubMed1998

Back and hip extensor fatigability in chronic low back pain patients and controls.

OBJECTIVE: To compare the lumbar paraspinal and gluteus maximus muscle fatigability between chronic low back pain patients and healthy controls by using electromyographic (EMG) spectral analysis during a maximal isometric endurance task. DESIGN: A cross-sectional comparative study between chronic low back pain patients and healthy control subjects. SETTING: Physical medicine and rehabilitation clinic in Finland. SUBJECTS: Twenty women with nonspecific chronic low back pain (longer than 3 months) and 15 healthy controls. INTERVENTION: Subjects performed maximal voluntary isometric back extensions (MVC) at 30 degrees forward flexion in a specially designed measurement unit. A 50% MVC load was used in isometric endurance test. OUTCOME MEASURES: Low back pain intensity was assessed by using the visual analogue scale and functional disability by the Oswestry disability index. Time to endurance was measured. Bipolar surface EMG recordings were made over the lumbar paraspinal muscles (L3-L4, L5-S1) and over the gluteus maximus muscles. Average EMG (aEMG%), and initial spectral median frequency (MFinit) and change over time (MFslope) were computed. RESULTS: Pain intensity and functional disability were higher and MVC and time to endurance were lower in the chronic low back pain group (p < .05). Similar muscle activity levels (aEMG%) and MFinit indicated similar muscle loading in both groups at the beginning of the endurance test. EMG spectral decreases (MFslope) indicated that lumbar paraspinal muscle fatigability was similar in both groups. In the chronic low back pain group, the gluteus maximus fatigued faster than in the control group (greater MFslope, p < .05). However, the shorter endurance time indicated greater fatigability in the chronic low back pain group in general (p < .05). CONCLUSIONS: The chronic low back pain patients were weaker and fatigued faster than the healthy controls. The EMG fatigue analysis results suggest that the gluteus maximus muscles are more fatigable in chronic low back pain patients than in healthy control subjects during a sustained back extension endurance test.

Adult↗
PubMed1994

The U.S. Navy Healthy Back Program: effect on back knowledge among recruits.

This study assessed the immediate effects of the U.S. Navy's Healthy Back Program in changing knowledge about back injury prevention. The prevalence of back problems among incoming recruits and correlates of back pain also were examined. Intervention recruits (n = 1,772) received the Healthy Back Program presentation, then completed a questionnaire. Control subjects (n = 1,658) completed an identical questionnaire but received no presentation. Intervention recruits scored significantly higher on back knowledge (67%) than controls (50%). About 41% of all recruits had experienced a back problem, 27% reported at least one back problem within the past year, and 11% reported back pain during recruit training. Lifting, sports participation, and bending were the leading causes of previous back problems. Better self-reported health and fitness were associated with fewer low back problems.

Adolescent↗
PubMed2004

Reliability and validity of the back performance scale: observing activity limitation in patients with back pain.

STUDY DESIGN: A single group design to examine reliability and validity of the Back Performance Scale. OBJECTIVES: To examine intertester reliability, test-retest reliability, and concurrent validity of the Back Performance Scale. SUMMARY OF BACKGROUND DATA: The Back Performance Scale is a condition-specific performance measure of activity limitation in patients with back pain. It includes five tests of daily activities requiring mobility of the trunk: sock test, pick-up test, roll-up test, fingertip-to-floor test, and lift test. Discriminative ability and responsiveness to important change have previously been demonstrated. METHODS: A total of 41 patients with back pain participated in the study. Two physiotherapists examined test performances concurrently, but independently. The patients filled in three questionnaires, two reflecting perceived disability (Der Funktionsfragenbogen Hannover, Roland-Morris Disability Questionnaire) as well as one for fear avoidance of daily activities and work (Fear Avoidance Belief Questionnaire). One physiotherapist retested the patients after 2 to 3 days. RESULTS: Intertester agreement of the Back Performance Scale sum score was very high (intraclass correlation coefficient 2.1): 0.996. Within-patient standard deviation (sw) on the 16-point Back Performance Scale was very low: 0.25. Test-retest reliability was high (intraclass correlation coefficient = 0.91, sw = 1.3). Intertester agreement of the separate tests was also very high, ranging from kappa= 0.90-1.00. Test-retest reliability was moderate to high (kappa= 0.55-0.83). A high correlation was demonstrated between the Back Performance Scale and the Der Funktionsfragenbogen Hannover: Spearman rho (rho) = 0.825, P < 0.01. Correlation between the Back Performance Scale and Roland-Morris Disability Questionnaire was moderate: rho = 0.454, P < 0.01. No correlation was demonstrated between the Back Performance Scale and the Fear Avoidance Belief Questionnaire. CONCLUSION: The Back Performance Scale appears to be a reliable and valid outcome measure of activity limitation.

Activities of Daily Living↗
PubMedDate not supplied

A history of low back injury is a risk factor for recurrent back injuries in varsity athletes.

In this prospective study, we investigated whether a history of previous low back injury and dissatisfaction with a coach and teammates could predict future low back injury in varsity athletes during a 1-year follow-up period. Of 679 Yale varsity athletes surveyed in 1999, 18.3% (124) reported that they had sustained a low back injury within the past 5 years, and 6.8% (46) sustained a low back injury in the follow-up season. There were no differences in incidence rates between men and women or between athletes involved in contact or noncontact sports. A history of low back injury was the significant predictor for sustaining low back injury in the following year, and athletes who reported previous low back injury were at three times greater risk. Athletes who still had pain at the time of the survey were six times more likely to sustain a low back injury than were athletes without a history of low back injury. These results suggest that some risk factors associated with a history of low back injury predispose athletes to sustain recurrent injury. They may be congenital or a result of insufficient recovery time after the first low back injury episode.

Adult↗
PubMed1999

Predictors of isokinetic back muscle strength in patients with low back pain.

STUDY DESIGN: Testing for trunk muscle strength was performed on 105 patients with chronic low back pain. OBJECTIVES: To investigate prediction of isokinetic back muscle strength in patients with low back pain. SUMMARY OF BACKGROUND DATA: The clinical evaluation of patients with chronic low back pain often in difficult because of discrepancy between disability and impairment. The isokinetic trunk device was developed as a tool for objective assessment of back muscle strength. However, the performance of patients depends on radiologic abnormalities of the spine, conditions of the back muscles, and various psychosocial factors. Studies are warranted that address how these variables influence back muscle strength. METHODS: The patients with chronic low back pain were tested by an isokinetic trunk muscle strength test (Cybex TEF, Ronkonkoma, NY). In addition, the following variables were recorded: gender, age, body mass index, emotional distress, pain on exertion, self-efficacy for pain, degenerative changes of the lumbar spine, cross-sectional area, and density of the erector spinae muscles. The three latter variables were estimated by computed tomography scans. The sum of the total work performed during isokinetic extension strength test was the dependent variable in a multiple regression analysis, and anthropometric, demographic, psychological, and radiologic factors were independent variables. RESULTS: Gender, cross-sectional muscle area, and pain on exertion were the most powerful predictors of isokinetic back muscle strength. The final regression model, which included these variables, could account for approximately 40% of the variability in back muscle strength. CONCLUSION: For assessing the results of an isokinetic trunk muscle strength test, cross-sectional muscle area, gender, and pain on exertion should be taken into account.

Adult↗
PubMed2003

Back pain online: a cross-sectional survey of the quality of web-based information on low back pain.

STUDY DESIGN: A cross section of Web sites accessible to the general public was surveyed. OBJECTIVE: To evaluate the quality of information on low back pain and its treatment that a "typical" patient user might access on the Internet. SUMMARY OF BACKGROUND DATA: Individuals with back pain have a desire to learn about their condition, what to expect, and what they can do about it. Web sites play a potentially useful role in providing information to help people learn about their low back pain and select the most appropriate methods of management. METHODS: A general search using popular search engines located 60 Web sites about back pain for review. A list of criteria for evaluating and scoring back pain Web sites was established using available literature and current clinical guidelines for the management of acute low back pain. The total quality score (maximum score, 38) was composed of two separate scores: one for general quality of the site (maximum score, 14) and one for site content specific to low back pain (maximum score, 24). Statistical tests, as appropriate, were used to investigate the relation between general indicators of Web site quality and total scores obtained. RESULTS: The quality of the Web sites surveyed was poor, most of them (n = 58, 97%) scoring less than half the maximum available score. The mean total score was 7.4 (range, 2-25). The mean score was 4.9 (range, 1-12) for general Web site quality and 2.4 (range, 1-13) for content specific to low back pain. Web sites providing references, sites created more recently, and sites not created for advertising purposes tended to be of better quality. CONCLUSIONS: This study highlighted the poor quality of information, particularly information about low back pain, available to "typical" patient users on the Internet. Health care professionals must have a role in evaluating existing information and in developing good-quality evidence-based Web sites. Patients with back pain should be discouraged from using the Internet as a source of information unless the Web sites they access have been evaluated and found to provide evidence-based messages.

Back Pain↗
PubMed2004

Back schools for non-specific low-back pain.

BACKGROUND: Since the introduction of the Swedish back school in 1969, back schools have frequently been used for treating patients with low-back pain (LBP). However, the content of back schools has changed and appears to vary widely today. OBJECTIVES: To assess the effectiveness of back schools for patients with non-specific LBP. SEARCH STRATEGY: We searched the MEDLINE and EMBASE databases and the Cochrane Central Register of Controlled Trials to May 2003 for relevant trials reported in English, Dutch, French or German. We also screened references from relevant reviews and included trials. SELECTION CRITERIA: Randomized controlled trials (RCTs) that reported on any type of back school for non-specific LBP were included. DATA COLLECTION AND ANALYSIS: Four reviewers, blinded to authors, institution and journal, independently extracted the data and assessed the quality of the trials. We set the high quality level, a priori, at a trial meeting six or more of 11 internal validity criteria. As data were clinically and statistically too heterogeneous to perform a meta-analysis, we used a qualitative review (best evidence synthesis) to summarize the results. The evidence was classified into four levels (strong, moderate, limited or no evidence), taking into account the methodological quality of the studies. We also evaluated the clinical relevance of the studies. MAIN RESULTS: Nineteen RCTs (3584 patients) were included in this updated review. Overall, the methodological quality was low, with only six trials considered to be high quality. It was not possible to perform relevant subgroup analyses for LBP with radiation versus LBP without radiation. The results indicate that there is moderate evidence suggesting that back schools have better short and intermediate-term effects on pain and functional status than other treatments for patients with recurrent and chronic LBP. There is moderate evidence suggesting that back schools for chronic LBP in an occupational setting, are more effective than other treatments and placebo or waiting list controls on pain, functional status and return to work during short and intermediate-term follow-up. In general, the clinical relevance of the studies was rated as insufficient. REVIEWERS' CONCLUSIONS: There is moderate evidence suggesting that back schools, in an occupational setting, reduce pain, and improve function and return-to-work status, in the short and intermediate-term, compared to exercises, manipulation, myofascial therapy, advice, placebo or waiting list controls, for patients with chronic and recurrent LBP. However, future trials should improve methodological quality and clinical relevance and evaluate the cost-effectiveness of back schools.

Exercise↗
PubMed2006

[The role of an information booklet or oral information about back pain in reducing disability and fear-avoidance beliefs among patients with subacute and chronic low back pain. A randomized controlled trial in a rehabilitation unit].

OBJECTIVES: To compare the efficacy of an information booklet or oral information about back pain in reducing disability and fear-avoidance beliefs among patients with subacute and chronic low back pain referred to a rehabilitation department. METHODS: An alternate-month design was used for 142 patients with subacute or chronic low back pain who were hospitalized for treatment. Seventy-two patients received written standardized information about back pain (the "back book") and usual physical therapy (intervention group), and 70 received usual physical therapy only along with nonstandardized oral information (control group). The main outcome measure was disability (measured on the Quebec back-pain disability scale), and secondary outcome measures were pain intensity (measured on a visual analog scale), fear-avoidance beliefs (measured on the Fear-Avoidance Beliefs Questionnaire [FABQ] Physical component), and knowledge of the relation of back pain to physical activity assessed at baseline, just before discharge from the hospital and 3 months after discharge. Satisfaction related to the information received was assessed on the day of discharge. RESULTS: Receiving the "back book" had a significant impact on disability at 3 months, from 48.40+/-14.55 to 34.57+/-18.42 in the intervention group and from 52.17+/-16.88 to 42.40+/-14.95 in the control group (p=0.03). Receipt of the book also had a significant impact on patients' knowledge and satisfaction about information but a nonsignificant effect on fear-avoidance beliefs. CONCLUSIONS: Providing an information booklet about back pain to patients with subacute and chronic low back pain referred to a rehabilitation unit contributes to reduced disability in these patients.

Adult↗
PubMed1997

Correlates of back problems and back-related disability in the United States.

The purpose of this study is to identify correlates of back problems and back disability in the adult population of the United States. Cross-sectional analyses were performed using data from the 1989 National Health Interview Survey (NHIS). Weighted polytomous logistic regression modeling was performed to estimate odds ratios adjusted for the effects of covariates. The prevalence of a disabling back condition, vs. no back condition, was relatively higher among subjects aged 25-64 years, male, non-high-school graduates, unemployed, living in the West, with disabling non-back morbidities, and with body mass index and weight above the 50th percentile. Among workers, those in technical, sales, clerical, private household, service, precision production and repair, or transportation occupations were relatively more likely to report disabling back conditions, compared to workers in professional occupations. Among adults with back problems, age greater than 34 years, weight above the 50th percentile, and history of back trauma were associated with chronic back disability. Although the magnitudes of the associations are not large, they may have enormous public health implications because of the high prevalence of back problems and related disability.

Adult↗
PubMedDate not supplied

[Function of back extensor muscles in upright standing position and during sitting with identical back posture--an electromyography study].

PROBLEM: There is a controversial discussion about the loading of the spine by the force of the extending muscles of the back in upright sitting with the back curved as in upright standing. Experimental studies investigating this issue are still lacking. METHODS: In the study presented in this paper we measured in 30 subjects the activity of the extending back muscles both in a natural upright standing posture and in sitting with identical posture of the back as recommended in some back training programs. To this end we recorded the electromyographical surface activity of the back muscles at four levels of the spine in both postures. The EMG activities were intraindividually normalized with reference to the respective activity recorded at maximum voluntary isometric contraction (MVC). RESULTS: At three of the four levels of the spine examined, the group averages of the EMG activity in sitting were significantly higher than in standing (p < 0.001). The maximum activity enhancement evaluated was 48% at Th12. The force of the lower back muscles in sitting with a posture of the back as in natural upright standing could be estimated to be at least greater than 30% of the force at MVC. CONCLUSION: The force needed to enforce in sitting a posture of the back identical to the posture at natural standing entails lower back muscle fatigue in a few minutes. The results of our study agree with recent experimental findings about an increased loading of the spine in lordotic sitting.

Adolescent↗
PubMed2001

"Active back school", prophylactic management for low back pain: three-year follow-up of a randomized, controlled trial.

The purpose of the present study was to investigate the long-term effect of the Active Back School programme on minimizing recurrences of episodes of low back pain. Forty-three subjects were randomly allocated to the Active Back School group and 38 to the control group. There were no significant differences between the groups with regard to baseline characteristics. The Active Back School programme comprised 20 lessons each divided into a 20-min theoretical and a 40-min exercise part during a 13-week period. Nine participants (11%) dropped out during the study period. Recurrence of new low back pain episodes was significantly less (p = 0.04), and the time from inclusion to the first new low back pain episode was significantly on the side of the Active Back School group (p < 0.01). The duration of sick leave was found to be significantly shorter (p < 0.01) in the Active Back School group compared to the control group. The Active Back School reduced the recurrence and severity of new low back pain episodes at 36 months' follow-up.

Adult↗
PubMed1991

Previous back pain and risk of developing back pain in a future pregnancy.

Four hundred twenty-nine pregnant women who had back pain before pregnancy and 375 pregnant women with no previous back pain were followed at regular intervals from the 12th week of pregnancy until delivery; back-pain complaints were recorded. Overall , back pain occurred twice as often in the group with a back-pain history (period prevalence) (P less than 0.001). The point prevalence of back pain in weeks 12, 24, 30, and 36 was three times higher in the group who had had back pain before pregnancy indicating that pain was not only more prevalent but also lasted longer in that group. Women who had been pregnant previously tended to have an increased risk of back pain, and there was a statistically significant correlation between multiparity and longer periods of back pain (P less than 0.001). Young age increased the risk of back pain (P less than 0.001). Pain intensity was higher in the younger women during the first part of their pregnancies but not later on (P less than 0.05).

Adult↗