Longitudinal quantitative measures of the natural course of low back pain recovery

Wearable motion-based platform for functional spine health assessment

INTRODUCTION

Low back pain is a significant burden to society and the lack of reliable outcome measures, combined with a prevailing inability to quantify the biopsychosocial elements implicated in the disease, impedes clinical decision-making and distorts treatment efficacy. This paper aims to validate the utility of a biopsychosocial spine platform to provide standardized wearable sensor-derived functional motion assessments to assess spine function and differentiate between healthy controls and patients. Secondarily, we explored the correlation between these motion features and subjective biopsychosocial measures.

METHODS

An observational study was conducted on healthy controls (n=50) and patients with low back pain (n=50) to validate platform utility. The platform was used to conduct functional assessments along with patient-reported outcome assessments to holistically document cohort differences. Our primary outcomes were motion features; and our secondary outcomes were biopsychosocial measures (pain, function, etc).

RESULTS

Our results demonstrated statistically significant differences in motion features between healthy and patient cohorts across anatomical planes. Importantly, we found velocity and acceleration in the axial plane showed the largest difference, with healthy controls having 49.7% and 55.7% higher values, respectively, than patients. In addition, we found significant correlations between motion features and biopsychosocial measures for pain, physical function and social role only.

CONCLUSIONS

Our study validated the use of wearable sensor-derived functional motion metrics in differentiating healthy controls and patients. Collectively, this technology has the potential to facilitate holistic biopsychosocial evaluations to enhance spine care and improve patient outcomes.

TRIAL REGISTRATION NUMBER

NCT05776771.

Biomechanical Phenotyping of Chronic Low Back Pain: Protocol for BACPAC

OBJECTIVE

Biomechanics represents the common final output through which all biopsychosocial constructs of back pain must pass, making it a rich target for phenotyping. To exploit this feature, several sites within the NIH Back Pain Consortium (BACPAC) have developed biomechanics measurement and phenotyping tools. The overall aims of this article were to: 1) provide a narrative review of biomechanics as a phenotyping tool; 2) describe the diverse array of tools and outcome measures that exist within BACPAC; and 3) highlight how leveraging these technologies with the other data collected within BACPAC could elucidate the relationship between biomechanics and other metrics used to characterize low back pain (LBP).

METHODS

The narrative review highlights how biomechanical outcomes can discriminate between those with and without LBP, as well as among levels of severity of LBP. It also addresses how biomechanical outcomes track with functional improvements in LBP. Additionally, we present the clinical use case for biomechanical outcome measures that can be met via emerging technologies.

RESULTS

To answer the need for measuring biomechanical performance, our "Results" section describes the spectrum of technologies that have been developed and are being used within BACPAC.

CONCLUSION AND FUTURE DIRECTIONS

The outcome measures collected by these technologies will be an integral part of longitudinal and cross-sectional studies conducted in BACPAC. Linking these measures with other biopsychosocial data collected within BACPAC increases our potential to use biomechanics as a tool for understanding the mechanisms of LBP, phenotyping unique LBP subgroups, and matching these individuals with an appropriate treatment paradigm.

Functional Tests Predicting Return to Work of Workers with Non-Specific Low Back Pain: Are There Any Validated and Usable Functional Tests for Occupational Health Services in Everyday Practice? A Systematic Review

The literature predominantly advocates subjective perception of disability and pain as an outcome measure for the functional evaluation of patients with low back pain (LBP). Physical outcome measurements are almost completely ignored. In this systematic review, we focused on physical functional measurements that can contribute to the prediction of patients' return to work (RTW) readiness after sick leave or rehabilitation. Searches were conducted in July 2022 without any time limit in the Cochrane Library, PEDro, PubMed and Scopus databases for functional and clinical tests reliable and applicable in clinical practice without demanding equipment. Two independent researchers extracted the data from the included articles in a standardised data collection form, and a third researcher validated the data extraction. No date restriction was applied. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in conducting the review. We found seven original articles, including six with an impact on predicting RTW. We found four fair and three poor original studies fulfilling our criteria. We found the Back Performance Scale (BPS) and back endurance test to be the most promising tests for occupational health service and the clinical practitioner. Radiation of back pain, with or without neurological deficiencies, had some predictive value in terms of RTW, too. The working conditions vary a lot, which causes inconsistency in the studies and in their interpretation. Functional tests could complete the widely used working ability evaluations methods such as the Work Ability Index (WAI) and are worth considering for future research. Overall, more research is needed in this field. The question of when LBP patients can resume everyday activities and work is not possible to determine with functional tests alone. Psychosocial aspects and work demands must be considered. PROSPERO: CRD42022353955. The study was funded by the University of Helsinki.

Quantitative dynamic wearable motion-based metric compared to patient-reported outcomes as indicators of functional recovery after lumbar fusion surgery

BACKGROUND

Low back pain is a debilitating condition with poor patient outcomes despite the use of a wide variety of diagnostic and treatment modalities. A lack of objective metrics to support clinical decision-making may be a reason for these poor outcomes. This study aimed to compare patient recovery following lumbar fusion surgery using an objective motion-based metric (functional performance) and subjective patient-reported outcomes for pain, disability and kinesophobia.

METHODS

A prospective observational study was conducted on 121 patients that received a lumbar fusion surgery. A wearable motion system was used to quantify three-dimensional multi-planar lumbar motion and benchmark each patient's lumbar function prior to surgery and post-operatively at follow-up time points for up to 2 years. Patient recovery profiles after surgery were evaluated using the acquired functional motion data and compared to patient-reported outcomes.

FINDINGS

Our results found significant improvement after surgery in objective functional performance as well as patient-reported pain, disability, and kinesophobia. However, we found a delayed response in the objective metric, with meaningful improvement occurring only 6 months after fusion surgery. In contrast, we found significant improvement in all subjective scores as early as 6 weeks post-surgery.

INTERPRETATION

Objective motion-based metric provides a unique perspective to assessing patient's functional recovery. While it is associated with dimensions of pain, disability and fear avoidance, it is also distinct and assesses a uniquely different dimension of functional health. This information can form the basis for the use of objective metrics to gauge patient recovery after lumbar fusion surgery.

Changes in Lumbo-Pelvic Coordination of Individuals With and Without Low Back Pain When Wearing a Hip Orthosis

Individuals with low back pain demonstrate an abnormal lumbo-pelvic coordination compared to back-healthy individuals. This abnormal coordination presents itself as a reduction in lumbar contributions and an increase in pelvic rotations during a trunk forward bending and backward return task. This study investigated the ability of a hip orthosis in correcting such an abnormal lumbo-pelvic coordination by restricting pelvic rotation and, hence increasing lumbar contributions. The effects of the hip orthosis on the lumbo-pelvic coordination were investigated in 20 low back pain patients and 20 asymptomatic controls. The orthosis reduced pelvic rotation by 12.7° and increased lumbar contributions by 11%. Contrary to our expectation, orthosis-induced changes in lumbo-pelvic coordination were smaller in patients; most likely because our relatively young patient group had smaller unrestricted pelvic rotations compared to asymptomatic individuals. Considering the observed capability of a hip orthosis in causing the expected changes in lumbo-pelvic coordination when there is a relatively large pelvic contribution to trunk motion, application of a hip orthosis may provide a promising method of correcting abnormal lumbo-pelvic coordination, particularly among patients who demonstrate larger pelvic rotation, that warrants further investigation.

A Spinal Motion Measurement Protocol Utilizing Inertial Sensors Without Magnetometers

This study presents an approach for instrumenting a spinal motion measurement protocol using two inertial measurement units (IMU)s affixed at the posterior pelvis and superior trunk. The accuracy of the inertial motion measurement instrumentation in tracking the relative orientation of the trunk with respect to the pelvis in three spinal motions (flexionextension, side bending, and rotation) is compared to that of a concurrent optical motion capture (mocap) system. Six healthy adults $(31.5 \pm 11.2$; 2 females) were recruited to perform the spinal motions. The results show minimal deviations of the IMU measurements from those of the mocap system (RMSE $\lt 2 \deg $, $\mathrm {r}\gt 0.84$ in all cases) and demonstrate the efficacy of the proposed instrumentation approach for spinal motion measurement.

Tracking Kinematic and Kinetic Measures of Sit to Stand using an Instrumented Spine Orthosis

Age related spinal deformity is becoming an increasingly prevalent problem, resulting in decreased quality of life. While spinal deformity can be corrected via surgical intervention, a large number of people with spinal fusions require follow-up surgery due to further degeneration. The identification of changes to a subjects kinematics and kinetics post-surgery are limited by a lack of methods to collect patient specific motion data over the course of surgical recovery. This paper introduces an Instrumented Spine Orthosis (ISO) that can capture the motions of the subjects torso without requiring the use of a control computer or other dedicated motion capture equipment. This system is used to collect the peak torso angles and velocities for a single subject performing sit-to-stand actions. The accuracy of the ISO is evaluated using motion capture, during different sit-to-stand protocols designed to highlight motion changes that have been seen in subjects with reduced mobility. This system was found to provide reliable measurements of these kinematic and kinetic torso measures across all tested motions, demonstrating the potential for the use of Instrumented Spine Orthotics to provide quantitative measures during the surgical recovery process.

Kinematic and Kinetic Validation of an Improved Depth Camera Motion Assessment System Using Rigid Bodies

The study of joint kinematics and dynamics has broad clinical applications, including the identification of pathological motions or compensation strategies and the analysis of dynamic stability. High-end motion capture systems, however, are expensive and require dedicated camera spaces with lengthy setup and data processing commitments. Depth cameras, such as the Microsoft Kinect, provide an inexpensive, marker-free alternative at the sacrifice of joint-position accuracy. In this work, we present a fast framework for adding biomechanical constraints to the joint estimates provided by a depth camera system. We also present a new model for the lower lumbar joint angle. We validate key joint position, angle, and velocity measurements against a gold standard active motion-capture system on ten healthy subjects performing sit to stand (STS). Our method showed significant improvement in mean absolute error and intraclass correlation coefficients for the recovered joint angles and position-based metrics. These improvements suggest that depth cameras can provide an accurate and clinically viable method of rapidly assessing the kinematics and kinetics of the STS action, providing data for further analysis using biomechanical or machine learning methods.

Do psychological and behavioral factors classified by the West Haven-Yale Multidimensional Pain Inventory (Swedish version) predict the early clinical course of low back pain in patients receiving chiropractic care?

Background

To investigate if psychological and behavioral factors (as determined by the Swedish version of the West Haven-Yale Multidimensional Pain Inventory, MPI-S) can predict the early clinical course of Low Back Pain (LBP).

Methods

MPI-S data from patients (18–65 years of age) seeking chiropractic care for recurrent and persistent LBP were collected at the 1^st visit. A follow-up questionnaire was administered at the 4^th visit. The predictive value of the MPI-S subgroups Adaptive Copers (AC), Interpersonally Distressed (ID) and Dysfunctional (DYS) was calculated against the subjective improvement at the 4^th visit and clinically relevant difference in pain intensity between the 1^st and 4^th visit.

Results

Of the 666 subjects who were included at the 1^st visit, 329 completed the questionnaire at the 4^th visit. A total of 64.7 % (AC), 68.0 % (ID) and 71.3 % (DYS) reported a definite improvement. The chance of “definite improvement”, expressed as relative risk (95 % CI) with the AC group as reference, was 1.05 (.87–1.27) for the ID and 1.10 (.93–1.31) for the DYS groups, respectively. The DYS and ID groups reported higher values in pain intensity both at the 1^st and the 4^th visit. The proportion of subjects who reported an improvement in pain intensity of 30 % or more (clinically relevant) were 63.5 % AC, 72.0 % ID and 63.2 % DYS. Expressed as relative risk (95 % CI) with the AC group as reference, this corresponded to 1.26 (.91–1.76) for the ID and 1.09 (.78–1.51) for the DYS groups, respectively.

Conclusions

The MPI-S instrument could not predict the early clinical course of recurrent and persistent LBP in this sample of chiropractic patients.

Trial registration

Clinical trials.gov; NCT01539863, February 22, 2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-0933-y) contains supplementary material, which is available to authorized users.

Low back functional health status of patient handlers

PURPOSE

The purpose of this study was to assess low back functional health among a group of nurses with a history of low back pain symptoms in a university hospital using a direct measure of low back functional performance and compare to traditional low back disability and pain questionnaires.

METHODS

Fifty-two nurses and patient care associates volunteered for the study. The clinical lumbar motion monitor (LMM) was used to directly measure low back functional performance. The participants performed a series of standard tasks involving trunk flexion and extension at different asymmetries. The LMM measures the motion signature of the participant (range of motion, velocity and acceleration) in all three planes of the body. The clinical LMM evaluation documented objective assessment of low back function normalized for age and gender. The Oswestry Disability Index (ODI) was used to evaluate self-reported disability and the McGill Pain Questionnaire visual analog scale assessed pain symptom.

RESULTS

The average functional performance probability was 0.49 with a standard deviation of 0.29, indicating that on average the functional performance was impaired. The average ODI score was 13.4 with a standard deviation of 11.6. The correlation between the functional performance probability and ODI was 0.046 (not statistically significant).

CONCLUSIONS

The clinical LMM functional performance measure provides a direct measure of trunk function. The low correlation between the ODI and clinical LMM functional performance probability indicates that the direct functional performance measure adds another component to our understanding of low back health or impairment that traditional questionnaires lack.

An experimental study investigating the effect of pain relief from oral analgesia on lumbar range of motion, velocity, acceleration and movement irregularity

Background

Movement alterations are often reported in individuals with back pain. However the mechanisms behind these movement alterations are not well understood. A commonly cited mechanism is pain. The aim of this study was to investigate the effect of pain reduction, from oral analgesia, on lumbar kinematics in individuals with acute and chronic low back pain.

Methods

A prospective, cross-sectional, experimental repeated-measures design was used. Twenty acute and 20 chronic individuals with low back pain were recruited from General Practitioner and self-referrals to therapy departments for low back pain. Participants complained of movement evoked low back pain. Inertial sensors were attached to the sacrum and lumbar spine and used to measure kinematics. Kinematic variables measured were range of motion, angular velocity and angular acceleration as well as a determining movement irregularity (a measure of deviation from smooth motion). Kinematics were investigated before and after administration of oral analgesia to instigate pain reduction.

Results

Pain was significantly reduced following oral analgesia. There were no significant effects on the kinematic variables before and after pain reduction from oral analgesia. There was no interaction between the variables group (acute and chronic) and time (pre and post pain reduction).

Conclusion

The results demonstrate that pain reduction did not alter lumbar range of motion, angular velocity, angular acceleration or movement irregularity questioning the role of pain in lumbar kinematics.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-304) contains supplementary material, which is available to authorized users.

Spine kinematics predict symptom and lost time recurrence: how much recovery is enough?

PURPOSE

The purpose of the study was to determine thresholds for low back kinematic measures for the amount of functional recovery necessary to reduce the risk of recurrent pain symptoms or lost time.

METHODS

Low back kinematic ability measures were collected at baseline when the workers returned to work for full duty. The range of motion, velocity, and acceleration were collected using the lumbar motion monitor.

RESULTS

Follow-up data was collected on 196 of the 206 workers. Workers with sagittal extension velocity of <40 deg./s at baseline were twice as likely to report recurrent low back pain symptoms. Workers with sagittal flexion velocity <34 deg./s were 3 times more likely to report lost time.

CONCLUSIONS

Kinematic functional performance measures may be used as recovery criteria in low back pain patients to minimize recurrence risk.

The prognosis of acute and persistent low-back pain: a meta-analysis

BACKGROUND

Although low-back pain is a highly prevalent condition, its clinical course remains uncertain. Our main objective was to systematically review the literature on the clinical course of pain and disability in patients with acute and persistent low-back pain. Our secondary objective was to investigate whether pain and disability have similar courses.

METHODS

We performed a meta-analysis of inception cohort studies. We identified eligible studies by searching MEDLINE, Embase and CINAHL. We included prospective studies that enrolled an episode-inception cohort of patients with acute or persistent low-back pain and that measured pain, disability or recovery. Two independent reviewers extracted data and assessed methodologic quality. We used mixed models to determine pooled estimates of pain and disability over time.

RESULTS

Data from 33 discrete cohorts (11 166 participants) were included in the review. The variance-weighted mean pain score (out of a maximum score of 100) was 52 (95% CI 48-57) at baseline, 23 (95% CI 21-25) at 6 weeks, 12 (95% CI 9-15) at 26 weeks and 6 (95% CI 3-10) at 52 weeks after the onset of pain for cohorts with acute pain. Among cohorts with persistent pain, the variance-weighted mean pain score (out of 100) was 51 (95% CI 44-59) at baseline, 33 (95% CI 29-38) at 6 weeks, 26 (95% CI 20-33) at 26 weeks and 23 (95% CI 16-30) at 52 weeks after the onset of pain. The course of disability outcomes was similar to the time course of pain outcomes in the acute pain cohorts, but the pain outcomes were slightly worse than disability outcomes in the persistent pain cohorts.

INTERPRETATION

Patients who presented with acute or persistent low-back pain improved markedly in the first six weeks. After that time improvement slowed. Low to moderate levels of pain and disability were still present at one year, especially in the cohorts with persistent pain.

Using a psychosocial subgroup assignment to predict sickness absence in a working population with neck and back pain

Background

The overall objective was to evaluate the predictive validity of a subgroup classification based on the Swedish version of the MPI, the MPI-S, among gainfully employed workers with neck pain (NP) and/or low back pain (LBP) during a follow-up period of 18 and 36 months.

Methods

This is a prospective cohort study that is part of a larger longitudinal multi-centre study entitled Work and Health in the Process and Engineering Industries (AHA). The attempt was to classify individuals at risk for developing chronic disabling NP and LBP. This is the first study using the MPI-questionnaire in a working population with NP and LBP.

Results

Dysfunctional individuals (DYS) demonstrated more statistically significant sickness absence compared to adaptive copers (AC) after 36 months. DYS also had a threefold increase in the risk ratio of long-term sickness absence at 18 months. Interpersonally distressed (ID) subgroup showed overall more sickness absence compared to the AC subgroup at the 36-month follow-up and had a twofold increase in the risk ratio of long-term sickness absence at 18 months. There was a significant difference in bodily pain, mental and physical health for ID and DYS subgroups compared to the AC group at both follow-ups.

Conclusions

The present study shows that this multidimensional approach to the classification of individuals based on psychological and psychosocial characteristics can distinguish different groups in gainfully employed working population with NP/LBP. The results in this study confirm the predictive validity of the MPI-S subgroup classification system.

Image-guided facet joint injection

Chronic spine pain poses a peculiar diagnostic and therapeutic challenge due to multiple pain sources, overlapping clinical features and nonspecific radiological findings. Facet joint injection is an interventional pain management tool for facet-related spinal pain that can be effectively administered by a radiologist. This technique is the gold standard for identifying facet joints as the source of spinal pain. The major indications for facet injections include strong clinical suspicion of the facet syndrome, focal tenderness over the facet joints, low back pain with normal radiological findings, post-laminectomy syndrome with no evidence of arachnoiditis or recurrent disc disease, and persistent low back pain after spinal fusion. The contraindications are more ancillary, with none being absolute. Like any synovial joint degeneration, inflammation and injury can lead to pain on motion, initiating a vicious cycle of physical deconditioning, irritation of facet innervations and muscle spasm. Image-guided injection of local anesthetic and steroid into or around the facet joint aims to break this vicious cycle and thereby provide pain relief. This outpatient procedure has high diagnostic accuracy, safety and reproducibility but the therapeutic outcome is variable.

How is recovery from low back pain measured? A systematic review of the literature

Recovery is commonly used as an outcome measure in low back pain (LBP) research. There is, however, no accepted definition of what recovery involves or guidance as to how it should be measured. The objective of the study was designed to appraise the LBP literature from the last 10 years to review the methods used to measure recovery. The research design includes electronic searches of Medline, EMBASE, CINAHL, Cochrane database of clinical trials and PEDro from the beginning of 1999 to December 2008. All prospective studies of subjects with non-specific LBP that measured recovery as an outcome were included. The way in which recovery was measured was extracted and categorised according to the domain used to assess recovery. Eighty-two included studies used 66 different measures of recovery. Fifty-nine of the measures did not appear in more than one study. Seventeen measures used pain as a proxy for recovery, seven used disability or function and seventeen were based on a combination of two or more constructs. There were nine single-item recovery rating scales. Eleven studies used a global change scale that included an anchor of 'completely recovered'. Three measures used return to work as the recovery criterion, two used time to insurance claim closure and six used physical performance. In conclusion, almost every study that measured recovery from LBP in the last 10 years did so differently. This lack of consistency makes interpretation and comparison of the LBP literature problematic. It is likely that the failure to use a standardised measure of recovery is due to the absence of an established definition, and highlights the need for such a definition in back pain research.

Quantitative dynamic measures of physical exposure predict low back functional impairment

STUDY DESIGN

Prospective field study of work exposure and changes in back function.

OBJECTIVE

Quantify dynamic physical exposures in the workplace and their association with decreases in kinematic back function (indicative of low back pain [LBP]).

SUMMARY OF BACKGROUND DATA

Previous epidemiologic studies of work have measured gross categories of exposure and found moderate relationships with LBP. More precise quantitative measures of exposure and spine function were hypothesized to increase the chances of identifying any significant associations.

METHODS

Three hundred and ninety real-time physical exposure measures were collected from distribution center workers performing repetitive manual materials handling tasks. Low back health effect measures were quantitatively measured prospectively for workers performing each of the jobs using a kinematic measure of function.

RESULTS

Significant decreases in spine function were observed in workers associated with 40% of the jobs sampled. Numerous significant univariate odds ratios were identified that indicated an association between physical exposure and decreased function. A multivariate model including right lateral trunk velocity, timing of the maximum dynamic asymmetric load moment exposure, and the magnitude of the dynamic sagittal bending moment predicted reduced spine function well. The model resulted in excellent sensitivity (85%) and specificity (87.5%) as well as excellent positive predictive value (89.5%) and negative predictive value (82.4%).

CONCLUSION

This study suggests that with proper quantification of job exposure and spine function, it is possible to identify which dynamic physical exposures are associated with reduced spine function and increases in LBP.

Quantification of a meaningful change in low back functional impairment

STUDY DESIGN

Repeated measures study design.

OBJECTIVE

Determine a meaningful change in low back functional impairment as measured with the lumbar motion monitor.

SUMMARY OF BACKGROUND DATA

A quantitative functional performance probability (P(n)) measure has been developed and is scored from 0.00 to 1.00. Previous research has shown that a 0.5 cut-off provides excellent sensitivity and specificity for identifying impaired and healthy low back function. However, a meaningful change in the P(n) measure has not been defined.

METHODS

The lumbar motion monitor was used to repeatedly measure P(n) in 3 groups of subjects including (1) asymptomatic, (2) recovering low back pain (LBP) and, (3) nonrecovering LBP. The asymptomatic group had 20 subjects. The recovering and nonrecovering LBP had 18 and 8 subjects, respectively. The asymptomatic group was tested 5 times at 1-week intervals. The 2 LBP groups were tested every 2 weeks for 3 months (6 evaluations).

RESULTS

The P(n) in the asymptomatic group did not significantly change over the observed period. On the basis of the variability in the asymptomatic group it was hypothesized that a meaningful change in P(n) was 0.14. The defined meaningful change was evaluated in 2 patient with LBP populations. The P(n) in the recovered LBP group significantly improved during the 3 month observation period and there was a corresponding reduction of symptoms. In the recovering LBP group the within subject standard deviation was 0.14 and all patients had at least 1 visit to visit change greater than 0.14. Furthermore, 11 of the 18 recovering patients with LBP had a meaningful change between the first 2 visits. In contrast, none of the nonrecovering LBP group had a meaningful change between the first 2 visits.

CONCLUSION

A meaningful change in P(n) was defined as 0.14.

The Back Disability Risk Questionnaire for work-related, acute back pain: prediction of unresolved problems at 3-month follow-up

OBJECTIVE

To assess the validity of the Back Disability Risk Questionnaire (BDRQ) to predict developing chronic back disability.

METHODS

Five hundred nineteen working adults (67% male) seeking outpatient care for acute, work-related back pain (<or=14 days) completed the BDRQ. After the initial medical evaluation, clinicians provided prognostic impressions in a 10-item questionnaire. Pain, functional limitation, and work status were assessed at 3-month follow-up.

RESULTS

In multivariate analyses, the presence of persistent pain, functional limitation, or impaired work status (31.4%) was predicted by six BDRQ questions: injury type, work absence preceding medical evaluation, job tenure, prior back surgery, worries about re-injury, expectation for early return-to-work, and stress. Classification accuracy at 3 months was 76.3%. Initial clinician impressions showed no multivariate associations with outcomes.

CONCLUSIONS

The BDRQ may provide prognostic information not observed in a routine medical evaluation for acute BP.

Effects of fear of movement on spine velocity and acceleration after recovery from low back pain

STUDY DESIGN

A cross-sectional assessment of the association between pain-related fear and joint motions and their higher order derivatives in 88 participants recently recovered from an episode of low back pain.

OBJECTIVE

To determine how the psychological construct of pain-related fear maps to motor behavior in standardized reaching tasks.

SUMMARY OF BACKGROUND DATA

Pain-related fear is a significant predictor of avoidance behavior and occupational disability in individuals with low back pain. However, it is not currently known how pain-related fear maps to motor behavior.

METHODS

Participants were tested at 4 weeks (+/-2 weeks) after resolution of a recent episode of back pain. Participants performed reaching tasks at comfortable and fast-paced movement speeds to 3 targets (high, middle, low) located in a midsagittal plane. Three-dimensional joint motions of the thoracic spine, lumbar spine, and hip were recorded using an electromagnetic tracking device. Group differences in joint excursions, peak velocities, and accelerations were assessed using 2-group (high pain-related fear, low pain-related fear) x 2-hand (left, right) x 2-movement speed (comfortable-pace, fast-pace) x 3-target height (high, middle, low) multivariate analyses of variances.

RESULTS

Individuals with high pain-related fear had smaller peak velocities and accelerations of the lumbar spine and hip joints for the fast-pace reaching trials.

CONCLUSION

The present study provides important evidence that pain-related fear is a robust construct that clearly maps on to differences in peak velocity and acceleration of the lumbar spine even after resolution of back pain.

Low back pain recurrence in occupational environments

STUDY DESIGN

Prospective assessment of return to work after low back pain.

OBJECTIVE

To determine which factors or combination of factors best predict recurrence of low back pain (defined 4 different ways) when returning to full-duty work.

SUMMARY OF BACKGROUND DATA

Recurrent back pain is one of the more costly health problems facing industry today. Few systematic evaluations of the various factors suspected of exacerbating low back pain have been reported in the literature.

METHODS

A total of 206 workers who reported low back pain were evaluated as they returned to full-duty work. Five types of assessments were performed including: 1) a low back kinematic functional assessments, 2) evaluation of job physical demands, 3) psychosocial assessment of the job environment, 4) self-reported impairment including perception of symptoms and psychological measures, and 5) personal (individual) factors. One year after return to full duty workers were interviewed to assess who had a recurrence of low back pain according to 4 different definitions of low back pain (symptom reports, medical visits, self-reported lost days, and employer-reported lost days due to back pain). Multiple logistic regression models were developed to assess the best combinations of predictors.

RESULTS

The most liberal definition of recurrence, recurrent symptoms, had a significantly greater recurrence rate at 58% than all other outcome measures (P = 0.0001). The medical visit recurrence rate of 36% was significantly greater than the more conservative lost time measures (P = 0.0001). The recurrence rate for self-reported lost time was 15%, whereas the more conservative employer confirmed lost time measure was significantly lower at 10% (P = 0.0077). Multivariate predictive models associated with the various recurrence definitions yielded sensitivities varying between 78% and 80% and specificity between 73% and 80%.

CONCLUSION

Recurrence is greatly dependent on how one defines recurrence with symptom reporting yielding 5.5 times as many recurrences compared with employer confirmed lost time. In general, more quantitative measures of worker musculoskeletal function yielded the best predictions of recurrence when predicting the more restrictive definitions of recurrence (employer confirmed lost time).

Pain-related fear is associated with avoidance of spinal motion during recovery from low back pain

STUDY DESIGN

A longitudinal assessment of the association between pain-related fear and joint motions in 36 participants with subacute low back pain.

OBJECTIVES

To determine how the psychologic construct of pain-related fear maps to motor behavior in standardized reaching tasks.

SUMMARY OF BACKGROUND DATA

Pain-related fear is a significant predictor of avoidance behavior and occupational disability in individuals with low back pain. However, it is not currently known how pain-related fear maps to motor behavior.

METHODS

Participants with an episode of subacute LBP were tested at 3, 6, and 12 weeks following pain onset. Participants performed reaching tasks at comfortable and fast-paced movement speeds to 3 targets (high, middle, low) located in a midsagittal plane. Three-dimensional joint motions of the thoracic spine, lumbar spine, and hip were recorded using an electromagnetic tracking device. Group differences in joint excursions were assessed using 2 groups (high pain-related fear, low pain-related fear) x 3 times (3, 6, 12 weeks) x 2 movement speeds (comfortable, fast paced) x 3 target heights (high, middle, low) MANOVAs.

RESULTS

Individuals with high pain-related fear had smaller excursions of the lumbar spine for reaches to all targets at 3 and 6 weeks, but not at 12 weeks following pain onset.

CONCLUSION

Individuals with high pain-related fear adopt alternative movement strategies and avoid motion of the lumbar spine when performing a common reaching movement. Identifying how pain-related fear maps to actual motor behavior (i.e., alternative movement strategies) is a crucial first step in determining how pain-related fear and motor behavior interact to promote or delay recovery from acute low back pain.

The role of the Back Rx exercise program in diskogenic low back pain: a prospective randomized trial

OBJECTIVE

To determine the efficacy of the Back Rx program in patients with diskogenic low back pain (LBP).

DESIGN

Prospective, randomized study.

SETTING

Outpatient setting of a major university teaching hospital.

PARTICIPANTS

Subjects with LBP greater than leg pain for at least 3 months duration and magnetic resonance imaging evidence of disk pathology. Fifty of 87 eligible patients consented and were randomized into age- and sex-matched groups.

INTERVENTIONS

Group I participated in the Back Rx program for 15 minutes a day, 3 times a week. All patients, from both groups, received celecoxib (200 mg) and hydrocodone (5 mg) with acetaminophen (500 mg) as needed, and wore a lumbar cryobrace for 15 minutes before bedtime.

MAIN OUTCOME MEASURES

Roland-Morris Disability Questionnaire score, numeric pain rating score, patient satisfaction score, measured forward flexion, use of celecoxib, hydrocodone, and acetaminophen, time off work, and rate of symptom recurrence.

RESULTS

At minimal 12-month follow-up, 70% of group I reported over 50% pain reduction with good or better patient satisfaction, compared with 33% in group II (P=.001). Average daily hydrocodone and acetaminophen use and time off work were less for group I (all, P<.05). Recurrence of symptoms at the end of the year was less for group I (P=.001).

CONCLUSIONS

Back Rx exercises, combined with use of a lumbar cryobrace and oral medications, yielded superior therapeutic results than with use of medications and cryobrace alone. Also significant was the reduced rate of recurrence in these patients.

The recovery patterns of back pain among workers with compensated occupational back injuries

OBJECTIVES

To investigate the longitudinal patterns of recovery among workers with compensated occupational back injuries.

METHODS

A longitudinal cohort study, with one-year follow-up via structured telephone interviews, among respondents off work because of "new" back injuries. Self-reported pain intensity was recorded at baseline and at four follow-up time points over the course of one year. Workers who answered the questionnaire on at least three occasions (n = 678) were classified into clusters according to their patterns of pain intensity over time using a two-step cluster analysis.

RESULTS

Four pain recovery patterns were identified: workers with high levels of pain intensity showing no improvement over time (43%); those experiencing recovery in the first four months with no further improvement or possibly even some deterioration, in the second half year (33%); those experiencing a slow consistent recovery but still with considerable back pain at the end of the follow-up (12%); and those quickly progressing to low level of pain or resolution (12%). Trajectories of average Roland-Morris Disability scores and SF-36 Role of Physical scores for above clusters mapped consistently with the corresponding patterns in pain. However, individuals with fluctuating, recurrent pain patterns showed the shortest cumulative duration on 100% benefit and the earliest return-to-work among other clusters.

CONCLUSIONS

Four clinically sensible patterns were identified in this cohort of injured workers, suggesting inter-individual differences in back pain recovery. The results confirm that recurrent or chronic back pain is a typical condition in respondents with new back injuries. Pain intensity and disability scores are good measures of recovery of back pain at the individual level. After initial return-to-work, or cessation of benefits, administrative measures of percentage of respondents back at work, or no longer on benefits, may not accurately reflect an individual's condition of back pain.

Disability associated with low back pain in Mulago Hospital, Kampala Uganda

BACKGROUND

Low back pain is sufficiently disabling and a common cause of disability particularly during the productive middle years of adult life. Disability implies interference with daily activities.

OBJECTIVE

To assess and document the disability associated with low back pain in terms of sick leave days, interference with daily activities and some pain characteristics.

METHODS

This study was carried out in the Orthopaedic out patient clinic of Mulago Hospital, a tertiary national referral hospital in Kampala, Uganda. It was a descriptive cross sectional study over a period of seven months. 204 patients with mechanical back pain were enrolled in the study, after screening all consecutive new adult patients referred with low back pain as the major complaint. A validated modified Oswestry instrument was used to collect data. Nine daily activities: sleep, sex, lifting, traveling, social and recreational activities, dressing, sitting, walking and running activities were investigated. Data was analyzed using SPSS for windows version 10. Mean and Standard deviations were used to summarize continuous variables. P value was considered statistically significant if it was equal or less than 0.05.

RESULTS

87% of the respondents reported a mean of 14 days off work during the 4 weeks prior to the interview because of back problems. The mean duration of a current low back pain episode was 5 months. All activities were interfered with; with lifting as the most affected with a mean score of 4.5, walking and running was 3.6, standing was 3.3, sex life was 2.9, traveling was 2.9, sitting was 2.7, social and recreational activities was 2.7, getting dressed was 2.1 and sleeping was 1.8.

CONCLUSION

Our results confirm that low back pain is a significant cause of disability affecting the productive middle years of adult life and causes significant disruption of daily activities including sleep and sex. The cost of lost work time, compensation and treatment for our setting is a knowledge gap that should be filled by further study. There is need for a community-based study to ascertain extent of the problem in at a wider population level.

Participation in occupational health longitudinal studies: predictors of missed visits and dropouts

PURPOSE

The purpose of this study is to determine whether demographics, health, and job factors influence continued participation of employed persons in a longitudinal intervention study of tertiary prevention for work-related low-back disorders (WR-LBDs).

METHODS

Four hundred fifty-four actively employed persons had enrolled in an intervention study of back supports and education to promote recovery from a WR-LBD. Baseline values were examined according to whether individuals continued in the study, missed a visit, or dropped out; frequency of missed visits; and early or late dropouts at follow-up intervals of 1, 2, 6, and 12 months.

RESULTS

Workers who did not complete all study visits were significantly more likely to be younger and have poorer self-reported health. Individuals with a greater percentage of body fat dropped out early. Significantly more missed visits were observed among those who had arthritis and longer duration of low-back pain symptoms. Job factors did not influence study participation.

CONCLUSIONS

Continued participation in a longitudinal study of working adults was influenced by age, health status, and factors related to the primary condition targeted by the intervention study. Strategies aimed at those who report lower levels of health and symptoms related to the condition under study may promote follow-up participation in longitudinal studies. Thus, even among actively employed persons, one should not assume that all workers are "healthy."

Multilevel Analysis of Individual and Contextual Factors as Predictors of Return to Work

OBJECTIVE

The objective of this study was to examine if individual and contextual levels of work environment factors predict return to work (RTW).

METHODS

Baseline data from 52 workplaces was linked to a national absence register. Four hundred twenty-eight persons with more than 2 weeks of sickness absence during a 2-year period were identified. Follow up was 1 year to examine three RTW outcomes. Multilevel logistic and Poisson regression models were used.

RESULTS

At the individual level, significant associations were found between one psychosocial and four physical factors and RTW within 4 weeks. Two physical factors predicted RTW within 1 year. Two psychosocial and two physical factors significantly prolonged duration of sickness absence. No significant contextual level risk factors were found.

CONCLUSION

At the individual level, both the psychosocial and physical work environment factors are important independent predictors of RTW.

The efficiency of multiple impulse therapy for musculoskeletal complaints

OBJECTIVE

The aim of the study was to document the response of patients to multiple impulse therapy for a variety of musculoskeletal complaints encountered in clinical practice.

METHODS

A single practitioner in a private clinic setting provided the therapy to 249 patients. Survival analysis was used to plot probability of pain vs the days required for symptom resolution for each of 8 patient complaints. Analysis of variance was used to examine the influence of covariates such as age, sex, body mass index, and chronicity.

RESULTS

The average number of visits required to achieve a pain-free state for each of 8 patient symptoms, the half-life for response to multiple impulse therapy, and comparison of the results of published studies of low back and neck pain are presented.

CONCLUSION

Response of patients in the study sample to multiple impulse therapy for symptoms of low back and neck pain appeared to be considerably faster than that obtained in 3 recent studies.

Differences among outcome measures in occupational low back pain

The rate of recurrence in low back pain patients has been reported as high as 70%; therefore, it is believed that researchers have a poor understanding of low back pain recovery. To enhance our understanding of recovery, a large cross-sectional study was conducted to compare outcome measures of return to work, impairment of activities of daily living, pain symptoms, and functional performance probability. A total of 208 workers were examined. The percentage of workers recovered based on return to work criteria was 99% compared to 25% for impairment of activities of daily living, 17% for symptoms, and 12.5% for functional performance probability. Single functional performance measures of range of motion, velocity, and acceleration had recovery rates of 59, 13, and 10%, respectively. It appears that all these criteria are measuring very different parameters of low back pain recovery. The residual loss in functional performance may indicate a decreased tolerance to physical demand providing potential insight for why recurrent low back pain rates are high.

Factors affecting recovery from work-related, low back disorders in autoworkers

OBJECTIVE

To simultaneously evaluate personal, medical, and job factors that could affect recovery from work-related, low back disorders, specifically focusing on an active working sample.

DESIGN

Observational, longitudinal study.

SETTING

Two US automotive plants.

PARTICIPANTS

Employees (N=352; 289 men, 63 women; mean age +/- standard deviation, 45.1+/-7.5 y) who were active hourly autoworkers, diagnosed with work-related, low back disorder by the plant's medical department.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Oswestry Disability Questionnaire for back pain was used to evaluate recovery.

RESULTS

Factors associated with better recovery were lower stress levels (P<.001) and exercise or physical activity outside work (P<.001); factors associated with higher disability levels over time were current cigarette smoking (P<.01) and bedrest (P<.001).

CONCLUSIONS

Personal modifiable factors are major influences in the recovery from work-related, low back disorders, even in active working populations. Interventions aimed at increasing exercise and decreasing stress should also be considered as a part of rehabilitation in employed persons with low levels of disability.

Revised protocol for the kinematic assessment of impairment

BACKGROUND CONTEXT

Marras et al. developed a functional motion performance tool that accurately identified impaired low back motion performance, with sensitivity of 90% and specificity of 94%. However, the protocol required testing of five controlled tasks and was relatively time consuming.

PURPOSE

To determine whether a more time-efficient low back motion functional performance evaluation tool with acceptably high sensitivity and specificity could be developed.

STUDY DESIGN/SETTING

Low back functional motion (kinematic) performance evaluations were completed on two groups, consisting of controls (no history of back pain) and low back pain patients. A second low back pain population was also evaluated prospectively to assess recovery.

PATIENT SAMPLE

The study population consisted of 335 patients and 374 controls. Thirty acute low back pain patients were monitored prospectively.

OUTCOME MEASURES

Kinematic low back functional performance measures.

METHODS

Low back motion functional performance was measured using the lumbar motion monitor. A revised discriminant function model was developed using data from only one of the five original functional motion performance control tasks. Prospective study data were used to track differences in recovery time between the revised and original discriminant function models.

RESULTS

The revised model using functional motion performance from the controlled sagittally symmetric task had a sensitivity of 90% and specificity of 92%. When comparing the revised and original model results, the time to recovery was the same in 90% of cases.

CONCLUSIONS

The revised (more time efficient) testing procedure yielded high sensitivity and specificity.

Biomechanical assessments of lumbar spinal function. how low back pain sufferers differ from normals. implications for outcome measures research. part i: kinematic assessments of lumbar function

OBJECTIVE

To review new and advanced biomechanical assessment techniques for the lumbar spine and illustrate the differences in lumbar function in patients with low back pain and asymtomatic subjects.

DATA SOURCES

The biomedical literature was searched for research and reviews on spinal kinematic differences between low back pain subjects and healthy controls. A data search for articles indexed on MEDLINE until April 2002 was performed.

RESULTS

Kinematic measurements of lumbar function were categorized into 3 areas where low back patients may differ from normals: (1) end range of motion during simple movements; (2) higher order kinematics (displacement, velocity, and acceleration) during complex movement tasks; and (3) spinal proprioception. The assessment of higher order kinematics during complex movement tasks is the most highly researched and the most successful in describing differences between the populations. The use of simple end range of motion appears questionable, while assessing spinal proprioception is the least researched, yet shows potential in highlighting differences between low back sufferers and asymptomatics.

CONCLUSION

Current kinematic biomechanical assessment techniques are capable of identifying functional differences between low back pain populations and controls. The use and validity of the majority of these techniques as outcome measures are currently unknown, yet may be valuable in generating functional diagnoses, evaluating the mechanisms of current therapies, and prescribing specific rehabilitation programs.

Mini-intervention for subacute low back pain: a randomized controlled trial

STUDY DESIGN

Randomized controlled trial.

OBJECTIVES

To investigate the effectiveness and costs of a mini-intervention, provided in addition to the usual care, and the incremental effect of a work site visit for patients with subacute disabling low back pain.

SUMMARY OF BACKGROUND DATA

There is lack of data on cost-effectiveness of brief interventions for patients with prolonged low back pain.

METHODS

A total of 164 patients with subacute low back pain were randomized to a mini-intervention group (A), a work site visit group (B), or a usual care group (C). Groups A (n = 56) and B (n = 51) underwent one assessment by a physician plus a physiotherapist. Group B received a work site visit in addition. Group C served as controls (n = 57) and was treated in municipal primary health care. All patients received a leaflet on back pain. Pain, disability, specific and generic health-related quality of life, satisfaction with care, days on sick leave, and use and costs of health care consumption were measured at 3-, 6-, and 12-month follow-ups.

RESULTS

During follow-up, fewer subjects had daily pain in Groups A and B than in Group C (Group A Group C, = 0.002; Group B Group C, = 0.030). In Group A, pain was less bothersome (Group A Group C, = 0.032) and interfered less with daily life (Group A Group C, = 0.040) than among controls. Average days on sick leave were 19 in Group A, 28 in Group B, and 41 in Group C (Group A Group C, = 0.019). Treatment satisfaction was better in the intervention groups than among the controls, and costs were lowest in the mini-intervention group.

CONCLUSIONS

Mini-intervention reduced daily back pain symptoms and sickness absence, improved adaptation to pain and patient satisfaction among patients with subacute low back pain, without increasing health care costs. A work site visit did not increase effectiveness.

Usefulness of functional outcome questionnaires in primary screening of spinal disease

Back pain screening clinics are established to clinically screen patients with back pain for organic lumbar pathology. The aim of this study is to assess the relationship between clinical signs of organic pathology and the level of disability as measured by functional outcome scores. Sixty-nine patients who were found to have clinical signs of organic pathology and 69 age- and sex-matched patients from 512 patients who were found to have no signs of organic pathology in the same time period in the back pain screening clinic were selected. The Oswestry Disability, Short Form-36, and visual analogue (pain) scores between the two groups were statistically analyzed. We found a significant increase in the level of disability in the group with organic pathology; however, the variation in the scores makes them unspecific for use in screening of acute spinal pathology. We also found a strong relationship between psychologic disability and length of symptoms.

Epidural lysis of adhesions and myeloscopy

Chronic low back pain is one of the most common ailments in modern medicine, with as many as 79% of patients with acute pain continuing to suffer with chronic or recurrent low back pain 1 year after its onset. Lumbar epidural fibrosis and post-lumbar laminectomy syndrome are increasingly recognized as being responsible for persistent low back pain. Estimations show that approximately 5% to 40% of lumbar surgeries result in failed back surgery syndrome. Epidural adhesiolysis with myeloscopy is an interventional technique based on the premise that the three-dimensional visualization of the contents of the epidural space provides the physician with the ability to directly visualize the structures, perform appropriate adhesiolysis, and administer drugs specifically to the target. This review describes pathophysiologic aspects, purposes and goals, rationale and indications, complications, and effectiveness of epidural lysis of adhesions with myeloscopy.

Work-related outcomes in occupational low back pain: a multidimensional analysis

OBJECTIVES

This pilot study explored a broad range of work-related outcomes for occupational low back injuries.

METHODS

A model of occupational outcomes and a survey instrument were developed on the basis of interviews, expert opinion, and literature reviews. New Hampshire workers who had an occupational back injury a year before the study were sampled from first reports of injury and sent a mailed survey about their postinjury experiences and related factors.

RESULTS

Of 251 randomly selected cases, a valid address could be identified for 121, and 99 patients responded. Almost 60% of the respondents had lost 1 week of work or more. At 1 year after injury, half of the respondents had returned to their preinjury job and employer, and 20% were unemployed, half of them because of the injury. Most working respondents reported no decrease in their work capacity. However, 68% still had pain exacerbated by work, and 47% worried that their condition would worsen with continued work. Reinjury occurred in 42% of the respondents. The work-related outcome measures were largely independent of each other. Exploratory multivariate analyses demonstrated unique patterns of factors associated with each outcome. Reinjury risk was significantly greater in respondents whose employers offered accommodations or whose postinjury jobs had greater ergonomic risk. The small sample size limited the ability to achieve statistically significant results in multivariate analyses.

CONCLUSIONS

Simply measuring return to work did not appear to capture the full range of job-related consequences from occupational back injuries in this pilot evaluation. Timing of return to work, occupational ergonomic risks, and appropriate job modifications appeared to be particularly important in a safe return to the job after an occupational low back injury. Results suggest opportunities to address risk factors that may improve work outcomes.