Relation between functional characteristics of the trunk and the occurrence of low back pain. Associated risk factors

Compensatory biomechanics and spinal loading during dynamic maneuvers in patients with chronic low back pain

Purpose

This study explores the biomechanics underlying the sit-to-stand (STS) functional maneuver in chronic LBP patients to understand how different spinal disorders and levels of pain severity relate to unique compensatory biomechanical behaviors. This work stands to further our understanding of the relationship between spinal loading and symptoms in LBP patients.

Methods

We collected in-clinic motion data from 44 non-specific LBP (NS-LBP) and 42 spinal deformity LBP (SD-LBP) patients during routine clinical visits. An RGB-depth camera tracked 3D joint positions from the frontal view during unassisted, repeated STS maneuvers. Patient-reported outcomes (PROs) for back pain (VAS) and low back disability (ODI) were collected during the same clinical visit.

Results

Between patient groups, SD-LBP patients had 14.3% greater dynamic sagittal vertical alignment (dSVA) and 10.1% greater peak spine torque compared to NS-LBP patients (p < 0.001). SD-LBP patients also had 11.8% greater hip torque (p < 0.001) and 86.7% greater knee torque (p = 0.04) compared to NS-LBP patients. There were no significant differences between patient groups in regard to anterior or vertical torso velocities, but anterior and vertical torso velocities correlated with both VAS (r = − 0.38, p < 0.001) and ODI (r = − 0.29, p = 0.01). PROs did not correlate with other variables.

Conclusion

Patients with LBP differ in movement biomechanics during an STS transfer as severity of symptoms may relate to different compensatory strategies that affect spinal loading. Further research aims to establish relationships between movement and PROs and to inform targeted rehabilitation approaches.

The Influence of Stretching the Hip Flexor Muscles on Performance Parameters. A Systematic Review with Meta-Analysis

The hip flexor muscles are major contributors to lumbar spine stability. Tight hip flexors can lead to pain in the lumbar spine, and hence to an impairment in performance. Moreover, sedentary behavior is a common problem and a major contributor to restricted hip extension flexibility. Stretching can be a tool to reduce muscle tightness and to overcome the aforementioned problems. Therefore, the purpose of this systematic review with meta-analysis was to determine the effects of a single hip flexor stretching exercise on performance parameters. The online search was performed in the following three databases: PubMed, Scopus, and Web of Science. Eight studies were included in this review with a total of 165 subjects (male: 111; female 54). In contrast to other muscle groups (e.g., plantar flexors), where 120 s of stretching likely decreases force production, it seems that isolated hip flexor stretching of up to 120 s has no effect or even a positive impact on performance-related parameters. A comparison of the effects on performance between the three defined stretch durations (30–90 s; 120 s; 270–480 s) revealed a significantly different change in performance (p = 0.02) between the studies with the lowest hip flexor stretch duration (30–90 s; weighted mean performance change: −0.12%; CI (95%): −0.49 to 0.41) and the studies with the highest hip flexor stretch duration (270–480 s; performance change: −3.59%; CI (95%): −5.92 to −2.04). Meta-analysis revealed a significant (but trivial) impairment in the highest hip flexor stretch duration of 270–480 s (SMD effect size = −0.19; CI (95%) −0.379 to 0.000; Z = −1.959; p = 0.05; I² = 0.62%), but not in the lowest stretch duration (30–90 s). This indicates a dose-response relationship in the hip flexor muscles. Although the evidence is based on a small number of studies, this information will be of great importance for both athletes and coaches.

Predictors for Nonspecific Low Back Pain in Rubber Farmers: A 1-Year Prospective Cohort Study

High prevalence of low back pain (LBP) has been reported among farmers. A number of contributing factors have been associated with LBP. However, predictors for LBP in this population are unknown. This longitudinally designed study aimed to identify the predictors of LBP in a sample of rubber farmers whose work involves heavy manual labor. Three hundred and twenty-seven rubber farmers, aged 18 to 70 years who reported no LBP in the previous year, were face-to-face interviewed and examined physically. The incidence of LBP was assessed monthly. The 12-month incidence of LBP in the cohort was 35%. Having a history of LBP (hazard ratio = 1.55, 95% confidence interval = 1.05-2.30) and an active job (hazard ratio = 1.98, 95% confidence interval = 1.16-3.40) were the predictors for the new onset of LBP in this sample. These 2 factors could therefore potentially be targeted to prevent or reduce the incidence of LBP in rubber farmers.

Risk Factors for Low Back Pain and Spine Surgery: A Retrospective Cohort Study in Soldiers

INTRODUCTION

Musculoskeletal low back pain (LBP) is commonly treated symptomatically, with practice guidelines advocating reserving surgery for cases that fail conservative care. This study examined medical comorbidities and demographic variables as risk factors for chronic/recurrent LBP, spinal surgery, and time to surgery.

METHODS

A 2015 retrospective cohort study was conducted in U.S. Army soldiers (N=1,092,420) from 2002 to 2011. Soldiers with medical encounters for LBP were identified using ICD-9 codes. Surgical treatment for LBP was identified according to Current Procedural Terminology codes. Comorbid medical conditions (psychological disorders, sleep disorders, tobacco use, alcohol use, obesity) and demographic variables were examined as risk factors for chronic/recurrent LBP within 1 year of the incident encounter, surgery for LBP, and time to surgery.

RESULTS

Of 383,586 patients with incident LBP, 104,169 (27%) were treated for chronic/recurrent LBP and 7,446 (1.9%) had surgery. Comorbid variables showed increased risk of chronic/recurrent LBP ranging from 26% to 52%. Tobacco use increased risk for surgery by 33% (risk ratio, 1.33; 95% CI=1.24, 1.44). Comorbid variables showed 10%-42% shorter time to surgery (psychological disorders, time ratio [TR]=0.90, 95% CI=0.83, 0.98; sleep disorders, TR=0.68, 95% CI=0.60, 0.78; obesity, TR=0.88, 95% CI=0.79, 0.98; tobacco use, TR=0.58, 95% CI=0.54, 0.63; alcohol use, TR=0.85, 95% CI=0.70, 1.05). Women showed 20% increased risk of chronic/recurrent LBP than men but 42% less risk of surgery.

CONCLUSIONS

In the presence of comorbidities associated with mental health, sleep, obesity, tobacco use, and alcohol use, LBP shows increased risk of becoming chronic/recurrent and faster time to surgery.

Incidence and risk factors for first-time incident low back pain: a systematic review and meta-analysis

BACKGROUND CONTEXT

Great effort has been made toward limiting low back pain (LBP). Recent focus has included factors involved with secondary and tertiary prevention, with less attention given to primary prevention.

PURPOSE

This review provided a current estimate of the incidence of LBP and risk factors associated with either first-time LBP or transition to LBP from a baseline of a pain-free state.

STUDY DESIGN

A systematic review and meta-analyses were performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

PATIENT SAMPLE

Studies included subjects aged 18 years or older, from longitudinal, observational, cohort designs that included baseline risk factors to an outcome of either first-time LBP or transition to LBP from a baseline of a pain-free state.

OUTCOME MEASURES

Risk factors and incidence rates were reported using descriptive analysis and the PRISMA guidelines.

METHODS

Electronic search strategies in PubMed, CINAHL/SPORTDiscus, and Cochrane Central Register of Controlled Trials were combined with a hand search to identify articles for inclusion. Studies were classified based on the population studied (community vs. occupational based) and type of LBP outcome (first ever vs. transition from a baseline pain-free state).

RESULTS

A total of 41 studies were included for review. Meta-analytical incidence rates for first-time LBP and transition to pain from a pain-free state were similar (∼25%), regardless of community or occupational populations. Risk factors for first-time LBP or transition to LBP from a baseline of a pain-free state were psychosocial and physically related. No consistent risk factor emerged as predictive of first-time LBP, although prior LBP was a consistent predictor of future incident LBP. Significant heterogeneity was found across studies in most models, which limits these findings.

CONCLUSIONS

The results of this study suggest that incidence of LBP is similar in community and occupational settings regardless of LBP definition. There were multiple diverse physical and psychosocial risk factors for first-time LBP. A history of LBP was the most consistent risk factor for transition to LBP from a baseline of a pain-free state.

Assessment of association between low back pain and paraspinal muscle atrophy using opposed-phase magnetic resonance imaging: a population-based study among young adults

STUDY DESIGN

A cross-sectional imaging study of young adults.

OBJECTIVE

To evaluate whether severity of low back symptoms predicts atrophy in the paraspinal muscles of young adults.

SUMMARY OF BACKGROUND DATA

Although an increased fat content of the lumbar muscles has been observed among adults with chronic LBP, there is limited knowledge of this association in younger populations.

METHODS

The population-based study sample consisted of 554 subjects (321 females and 233 males) from the 1986 Northern Finland Birth Cohort. Latent Class Analysis (LCA) was used to cluster the subjects according to the low back symptoms and functional limitations at 18, 19, and 21 years. The mean age of the subjects at the time of the MRI (magnetic resonance imaging) was 21 years (range, 20-23). Muscle atrophy was evaluated by assessing the fat content of the paraspinal muscles using Opposed-Phase MRI. The cross-sectional areas (CSAs) of the erector spinae and multifidus muscles were also measured.

RESULTS

LCA analysis produced five clusters differing in symptoms, ranging from a cluster (n = 65) in which subjects had high likelihood of symptoms and functional limitations at all time points, to a cluster (n = 165) with no pain ever. The fat content of the multifidus muscles was significantly higher among women than men (14.0% vs. 5.3%, P < 0.001), but it was not significantly associated with symptom severity. The CSA of both erector spinae and multifidus muscles were significantly larger among men than women (P < 0.001 in all of the muscles), but were not associated with pain severity.

CONCLUSION

Low back symptoms and functional limitations over a 3-year period were not associated with increased fat content or a reduction in the cross-sectional area of lumbar paraspinal muscles among young adults.

Computational model of the lumbar spine musculature: implications of spinal surgery

BACKGROUND

The development of a comprehensive and detailed model of the musculature of the lumbar region is required if biomechanical models are to accurately predict the forces and moments experienced by the lumbar spine.

METHODS

A new anatomical model representing the nine major muscles of the lumbar spine and the thoracolumbar fascia is presented. These nine muscles are modeled as numerous fascicles, each with its own force producing potential based on size and line of action. The simulated spine is fully deformable, allowing rotation in any direction, while respecting the physical constraints imposed by the skeletal structure. Maximal moments were predicted by implementing the model using a pseudo force distribution algorithm. Three types of surgery that affect the spinal musculature were simulated: posterior spinal surgery, anterior surgery, and total hip replacement.

FINDINGS

Predicted moments matched published data from maximum isometric exertions in male volunteers. The biomechanical changes for the three different types of surgery demonstrated several common features: decreased spinal compression and production of asymmetric moments during symmetric tasks.

INTERPRETATION

This type of analysis provides new opportunities to explore the effect of different patterns of muscle activity including muscle injury on the biomechanics of the spine.

[Physical movement - is it good for the back? Nationwide representative study on different effects of physical activity at the workplace and in leisure time]

Physical activity is an important component of primary and secondary prevention of orthopedic complaints such as back pain as well as for many other syndromes. This epidemiologic research project investigated the multifactorial interaction between physical leisure activities and back pain and also the question whether regular physical activity at the workplace can be equated with the effect of regular leisure activity. From a patients point of view this could be construed as an"excuse" to refrain from leisure and fitness sports. Within the framework of a cooperative project between the Orthopedic University Clinic in Heidelberg and the Robert-Koch Institute in Berlin, representative data were gathered for the first time in Germany on physical activity at the workplace and in leisure time as well as the prevalence of back pain. Within the first national health survey a random sample of 3,488 employed German citizens aged 18-69 years old was investigated with multiple logistic regression analyses.The prevalence of 7-day back pain in Germany was 34% and the prevalence for 1-year was 60%. Physical activity at the workplace was associated with a significantly higher risk for back pain whilst leisure sport activity was accompanied by a lower prevalence of back pain. Although 39% of all persons who were inactive in sport and physical activities claimed to have felt back pain at least once in a retrospective 7-day period, the corresponding values for persons active in sport were 33% (1-2 h sport/week), 27% (2-4 h sport/week) and 30% (>4 h sport/week).This study provides population-based epidemiologic data on the prevalence of back pain among employed German citizens for the first time since the reunification. Although causal conclusions cannot principally be derived from cross-sectional data, the results of this analysis allow the multifactorial conditional structure to be unraveled. Our data demonstrate that manual physical employment does not represent a substitute for fitness leisure sports, but physically demanding working conditions themselves represent a significant risk factor for back pain.

Incidence and trends of low back pain hospitalisation during military service--an analysis of 387,070 Finnish young males

BACKGROUND

There is evidence that low back pain (LBP) during young adulthood and military service predicts LBP later in life. The purpose of this study was to investigate the incidence and trends of LBP hospitalisation among Finnish military conscripts.

METHODS

All male conscripts performing their compulsory military service during 1990-2002 were included in the study population. Altogether 387,070 military conscripts were followed throughout their six-to-twelve-month service period. Data on LBP hospitalisations were obtained from the National Hospital Discharge Register.

RESULTS

Altogether 7,240 LBP hospitalisations were identified among 5,061 (1.3%) male conscripts during the study period. The event-based incidence of LBP hospitalisation was 27.0 (95% confidence interval (CI): 25.7-28.2). In most cases, the diagnosis was unspecified LBP (n = 5,141, 71%) followed by lumbar disc disorders (n = 2,069, 29%). Hospitalisation incidence due to unspecified LBP was 19.1 per 1,000 person-years (95% CI: 18.3 to 20.4), and 7.8 per 1,000 person-years (95% CI: 6.7 to 8.3) due to lumbar disc disorders. The incidence of unspecified LBP remained unaltered, while hospitalisation due to lumbar disc disorders declined from 1993 onwards.

CONCLUSION

Although conscripts accepted into military training pass physician-performed examinations as healthy, young adults, LBP hospitalisation causes significant morbidity during military service.

Physical characteristics of the back are not predictive of low back pain in healthy workers: a prospective study

Background

In the working population, back disorders are an important reason for sick leave and permanent work inability. In the context of fitting the job to the worker, one of the primary tasks of the occupational health physician is to evaluate the balance between work-related and individual variables. Since this evaluation of work capacity often consists of a physical examination of the back, the objective of this study was to investigate whether a physical examination of the low back, which is routinely performed in occupational medicine, predicts the development of low back pain (LBP).

Methods

This study is part of the Belgian Low Back Cohort (BelCoBack) Study, a prospective study to identify risk factors for the development of low back disorders in occupational settings. The study population for this paper were 692 young healthcare or distribution workers (mean age of 26 years) with no or limited back antecedents in the year before inclusion. At baseline, these workers underwent a standardised physical examination of the low back. One year later, they completed a questionnaire on the occurrence of LBP and some of its characteristics. To study the respective role of predictors at baseline on the occurrence of LBP, we opted for Cox regression with a constant risk period. Analyses were performed separately for workers without any back antecedents in the year before inclusion ('asymptomatic' workers) and for workers with limited back antecedents in the year before inclusion ('mildly symptomatic' workers).

Results

In the group of 'asymptomatic' workers, obese workers showed a more than twofold-increased risk on the development of LBP as compared to non-obese colleagues (RR 2.57, 95%CI: 1.09 – 6.09). In the group of 'mildly symptomatic' workers, the self-reports of pain before the examination turned out to be most predictive (RR 3.89, 95%CI: 1.20 – 12.64).

Conclusion

This study showed that, in a population of young workers wh no or limited antecedents of LBP at baseline, physical examinations, as routinely assessed in occupational medicine, are not useful to predict workers at risk for the development of back disorders one year later.

Directional sensitivity of velocity sense in the lumbar spine

Regulating spinal motion requires proprioceptive feedback. While studies have investigated the sensing of static lumbar postures, few have investigated sensing lumbar movement speed. In this study, proprioceptive contributions to lateral trunk motion were examined during paraspinal muscle vibration. Seventeen healthy subjects performed lateral trunk flexion movements while lying prone with pelvis fixed. A 44.5-Hz vibratory stimulus was applied to the paraspinal muscles at the L3 level. Subjects attempted to match target paces of 9.5, 13.5, and 17.5 deg/s with and without paraspinal muscle vibration. Vibration of the paraspinal musculature was found to result in slower overall lateral flexion. This effect was found to have a greater influence in the difference of directional velocities with vibration applied to the left musculature. These changes reflect the sensitivity of lumbar velocity sense to applied vibration leading to the perception of faster muscle lengthening and ultimately resulting in slower movement velocities. This suggests that muscle spindle organs modulate the ability to sense velocity of motion and are important in the control of dynamic motion of the spine.

A systematic review of the relation between physical capacity and future low back and neck/shoulder pain

The results of longitudinal studies reporting on the relation between physical capacity and the risk of musculoskeletal disorders have never been reviewed in a systematic way. The objective of the present systematic review is to investigate if there is evidence that low muscle strength, low muscle endurance, or reduced spinal mobility are predictors of future low back or neck/shoulder pain. Abstracts found by electronic databases were checked on several inclusion criteria. Two reviewers separately evaluated the quality of the studies. Based on the quality and the consistency of the results of the included studies, three levels of evidence were constructed. The results of 26 prospective cohort studies were summarized, of which 24 reported on the longitudinal relationship between physical capacity measures and the risk of low back pain and only three studies reported on the longitudinal relationship between physical capacity measures and the risk of neck/shoulder pain. We found strong evidence that there is no relationship between trunk muscle endurance and the risk of low back pain. Furthermore, due to inconsistent results in multiple studies, we found inconclusive evidence for a relationship between trunk muscle strength, or mobility of the lumbar spine and the risk of low back pain. Finally, due to a limited number of studies, we found inconclusive evidence for a relationship between physical capacity measures and the risk of neck/shoulder pain. Due to heterogeneity, the results of this systematic review have to be interpreted with caution.

Physical capacity in relation to low back, neck, or shoulder pain in a working population

AIMS

To investigate the longitudinal relation between physical capacity (isokinetic lifting strength, static endurance of the back, neck, and shoulder muscles, and mobility of the spine) and low back, neck, and shoulder pain.

METHODS

In this prospective cohort study, 1789 Dutch workers participated. At baseline, isokinetic lifting strength, static endurance of the back, neck, and shoulder muscles, and mobility of the spine were measured in the pain free workers, as well as potential confounders, including physical workload. Low back, neck, and shoulder pain were self-reported annually at baseline and three times during follow up.

RESULTS

After adjustment for confounders, Poisson generalised estimation equations showed an increased risk of low back pain among workers in the lowest sex specific tertile of performance in the static back endurance tests compared to workers in the reference category (RR = 1.42; 95% CI 1.19 to 1.71), but this was not found for isokinetic trunk lifting strength or mobility of the spine. An increased risk of neck pain was shown for workers with low performance in tests of isokinetic neck/shoulder lifting strength (RR = 1.31; 95% CI 1.03 to 1.67) and static neck endurance (RR = 1.22; 95% CI 1.00 to 1.49). Among workers in the lowest tertiles of isokinetic neck/shoulder lifting strength or endurance of the shoulder muscles, no increased risk of shoulder pain was found.

CONCLUSIONS

The findings of this study suggest that low back or neck endurance were independent predictors of low back or neck pain, respectively, and that low lifting neck/shoulder strength was an independent predictor of neck pain. No association was found between lifting trunk strength, or mobility of the spine and the risk of low back pain, nor between lifting neck/shoulder strength or endurance of the shoulder muscles and the risk of shoulder pain.

Validation of a self-administered questionnaire for assessing exposure to back pain mechanical risk factors

OBJECTIVE

To validate a self-administered questionnaire assessing exposure to mechanical risk factors, developed for a cohort study aiming at assessing the influence of physical and psycho-social factors on the incidence of low back pain (LBP).

METHODS

The study first involved a criterion validity test. A sample of the cohort workers (n=152) was observed at the workplace during four 30 min periods randomly distributed along the shift. At the end of the work shift, the questionnaire was filled in both by the worker and the observer. Agreements were tested between self-reports and observations, and between self-reports and observer opinion. Secondly, a comparison of exposure-effect relationships based on self-reports to those based on observations was carried out on the whole study cohort (n=716). Both sets of Relative Risks of being an incident case (LBP lasting at least 7 consecutive days in the follow-up year) were tested for heterogeneity.

RESULTS

Self-reports agreement levels were better with observer opinion than with observational data and were higher for answers at a dichotomous level. Vehicle driving, manual handling without estimation of weight and frequencies, or trunk bending without rotation showed a fair to good agreement with the external criteria. Limits in the validation procedure did not allow validating the sitting and standing durations. As regards the health outcome comparison, questionnaire and observations led to homogeneous Relative Risks for the variables tested.

CONCLUSIONS

Results show that self-reports provide a limited accuracy to assess actual frequencies and durations of work activities. Using a questionnaire, classifying the workers into exposure categories is rather relative, but questionnaire and observations seem similar in their relationships to outcome.

Workplace stress, lifestyle and social factors as correlates of back pain: a representative study of the German working population

OBJECTIVES

To investigate the prevalence of back pain in the German working population and the relationship between back pain and workplace stresses, lifestyle and social factors.

METHODS

The first National Health Survey of the Federal Republic of Germany was carried out between October 1997 and March 1999. It comprised a representative epidemiological cross-sectional study of the working population, with a total sample of 3,488 persons between the ages of 18 and 69 years. The participants took part in a medical examination and answered a self-rating questionnaire. The relationship between subjective back pain and workplace stresses and social and lifestyle factors was investigated with bivariate tests and multiple logistical regression analyses.

RESULTS

The 7-day prevalence for back pain in the German working population was found to be 34%, and the 1-year prevalence was 60%. The odds ratios were significantly higher in women, persons of lower socioeconomic status, married and depressed persons and non-athletes. Carrying heavy loads or maintaining a single working posture were the most significant work-related correlates of back pain, for members of both the female and male working population, while environmental stress and psychological stress correlated significantly with back pain in men only.

CONCLUSIONS

This study reports the first representative epidemiological prevalence data for back pain, and its correlates and potential risk factors, for the German working population. To reduce the negative impact of back pain the most promising behavioural and conditional prevention measures in the workplace would be to reduce carrying stress and to vary working posture. In addition, a more active, athletic lifestyle, plus the avoidance of being overweight, should provide an additional protective or preventive effect.

Low back pain: reliability of a set of pain measurement tools

OBJECTIVES

To determine the reliability and internal consistency of a set of low back pain (LBP)-related measurement tools and to determine whether they are appropriate for use in a large-scale, community-based sample in Israel.

DESIGN

Test-retest reliability study, with an interval of 2 to 14 days between test and retest.

SETTING

Physiotherapy clinics.

PARTICIPANTS

One hundred fifty-one patients with LBP.

MAIN OUTCOME MEASURES

The Modified Roland-Morris Disability Questionnaire (MRMQ); a simple verbal pain severity scale; and modified pain symptoms frequency and bothersomeness indices. Three measures of variables with potential association with LBP were also used: a Fear-Avoidance Beliefs Questionnaire (FABQ), work satisfaction scale, and the Baecke Physical Activity Questionnaire (BPAQ).

RESULTS

Test-retest reliability was high for the MRMQ, pain symptom indices, work index of the FABQ, and occupational activity index of the BPAQ; the internal consistency of the MRMQ and FABQ work index were also high (intraclass correlation coefficient >or= .89; alpha = .89).

CONCLUSIONS

Most measurement tools are reliable and suitable for community LBP studies in Israel.

Symmetry and linearity of trunk function in subjects with non-specific low back pain

Objective. To investigate the effect of a standard rehabilitation program on the symmetry of trunk kinematics in subjects with non-specific low back pain.Design. Assessing lumbar spine kinematics in the cardinal planes using dynamometry.Background. Previous evaluations of trunk symmetry focussed more on anatomical rather than functional symmetry. Correlation of functional symmetry with low back pain was occasionally performed, but only for base line evaluations. To the best of the author's knowledge, there is no study examining the effect of exercise on the functional symmetry of the trunk, especially in non-specific low back pain subjects.Methods. Two groups of young male subjects whose working conditions incurred long daily hours of sitting and standing participated in the study. Muscles of the lumbar spine were initially evaluated in the cardinal planes using dynamometry. The same parameters (maximum isometric torque, dynamic torque, angular velocity and range of motion) were then repeatedly measured throughout a standardized strength protocol lasting for 12 sessions over a four-week period.Results. As pain gradually disappeared over a one-month period of rehabilitation, certain factors of the trunk kinematics exhibited convergence towards perfect symmetry while others showed oscillations. Moreover, global right-left data for certain trunk kinematics exhibited near-perfect linear relationship.Conclusion. Functional symmetry of the trunk in the coronal and transverse planes can be used to assess the progress of rehabilitation programs of non-specific low back pain subjects. RelevanceRehabilitation programs focus on the progress of directly measured trunk kinematics, which do not always exhibit monotonic behavior. This paper alludes to the importance of tracking symmetry of trunk kinematics as it may help clinicians modify the strengthening protocols in order to achieve more rapid relief from back pain.

Disability measurement in persons with back pain: a validity study of spinal range of motion and velocity

OBJECTIVE

To evaluate the criterion validity and responsiveness to change of spine kinematic variables to assess disability in patients with low back pain.

DESIGN

Blinded comparison between spine kinematic variables, Oswestry disability questionnaire scores, and work status.

SETTING

Multidisciplinary occupational rehabilitation clinic of a university hospital.

PATIENTS

Population-based cohort of 111 patients with subacute work-related back pain who were absent from regular work for more than 4 weeks because of back pain.

INTERVENTIONS

This study was part of a population-based randomized clinical trial. Patients were randomized to 4 different methods of management: usual care, rehabilitation, ergonomics, or rehabilitation and ergonomics.

MAIN OUTCOME MEASURES

Oswestry disability questionnaire, kinematic analysis of the spine during flexion and extension of the trunk, and work status were collected at weeks 4, 12, 24, and 52 after the back accident.

RESULTS

Kinematic variables were poorly to moderately related to work status and Oswestry questionnaire scores. Kinematic variables were also unresponsive to change in work status and Oswestry questionnaire scores over time.

CONCLUSION

Spine kinematics during flexion and extension of the trunk do not appear to be a valid measure of disability in patients with subacute and chronic back pain.