Determinants of occupational disability following a low back injury: a critical review of the literature

The aim of this research was to determine prognostic indicators of work disability in occupational back pain as reported in the literature, by systematically searching the research literature, assessing the methodological quality of the research, and synthesizing the findings into a concise summary. An article was considered eligible for review if research participants had an injury of the back, the article was based on original research, published in English, and involved a cohort with back pain less than 6 months post injury with at least one follow up assessment. Each article was independently reviewed by two "blinded" reviewers using 19 appraisal criteria for methodological quality of prognostic studies. Nineteen studies met the methodological standard to be included. Time since onset, demographic factors, functional disability, psychological distress, pain reports, previous episodes, and work environment were identified as important prognostic factors. Most studies compartmentalized the factors they considered. What is needed is a comprehensive multivariate biopsychosocial job-related model of work disability.

Biopsychosocial multivariate predictive model of occupational low back disability

STUDY DESIGN

To establish outcome, 253 workers with subacute and chronic low back conditions were assessed with a comprehensive multimethod biopsychosocial protocol at baseline, 3 days after the initial examination, and 3 months later.

OBJECTIVE

To validate empirically a biopsychosocial model for prediction of occupational low back disability.

SUMMARY OF BACKGROUND DATA

Costs of low back occupational disability continue to spiral despite stabilization of low back injury rates. An empirically based model to predict occupational disability in workers with low back injuries is required.

METHODS

Workers with subacute low back injuries (4-6 weeks after injury, n = 192) and those with chronic back pain (6-12 months after injury, n = 61) were the study participants. The biopsychosocial protocol included five groups of variables: 1) sociodemographic, 2) medical, 3) psychosocial, 4) pain behavior, and 5) workplace-related factors. Predictive validity was investigated through a 3-month follow-up assessment, at which time the return to work outcome was determined. Stepwise logistic regression models were developed to predict work status.

RESULTS

The final integrated model consisted of variables from a wide biopsychosocial spectrum: vitality, health transition, feeling that job is threatened due to injury, expectations of recovery, guarding behavior, perception of severity of disability, time to complete walk, and right leg typical sciatica.

CONCLUSIONS

The "winning" variables identified in the integrated model are dominated by cognitions, which are accompanied by disability behaviors. A cognitive-behavioral model with an adaptation-oriented rather than a pathology-oriented focus is favored for early intervention with high-risk workers since cognitions are amenable to change.

Back injuries in the young athlete

The diagnosis of back pain in the young athlete should be specific and not attributed to nonspecific, mechanical causes. Risk factor identification and intervention are required. Treatment is then initiated in a specific pattern, addressing flexibility and muscular imbalances. Bracing is often used to allow healing of growth tissue. The lumbosacral orthosis may be molded in a lordotic posture to unload the disc or antilordotic posture to relieve the posterior column; however, customizing the lordosis to the individual biomechanics may be required. Spinal stabilization is initiated with therapy for strengthening isolated weaknesses and progressing to coactivation and proprioceptive techniques, such as the balance ball. Returning to competition is preceded with sport-specific training.

Validation of a questionnaire for assessing physical work load

OBJECTIVES

Reliable, valid, and compatible methods are required for exploring the complex interactive effects of psychosocial and physical stressors on complaints and disorders. An instrument for assessing physical work load that integrates information from a biomechanical model of lumbar load is presented and validated.

METHODS

Four hundred and fifty-five people working in nursing homes for elderly people in Germany filled out the developed questionnaire 3 times within 1 year. Test-retest reliability was calculated, and validity was checked several times. Relationships with other, theoretically related and unrelated variables were examined.

RESULTS

The test-retest reliability of the questionnaire measures was about 0.65. The convergent and discriminant validity was satisfactory, and the questionnaire was able to separate professional subgroups with different physical work loads. The Spearman rank-order correlations between physical load and musculoskeletal complaints were about 0.30.

CONCLUSIONS

The method developed in this study is a reliable and valid instrument for assessing physical work load. The integration of statistical methods from psychological testing and theory in the development of methods exploring the effects of physical work load is advocated.

Physical workload, ergonomic problems, and incidence of low back injury: a 7.5-year prospective study of San Francisco transit operators

BACKGROUND

The etiologic role of biomechanical factors for low back injury (LBI) needs to be confirmed in prospective studies that control for psychosocial factors.

METHODS

Complete baseline information on 1,233 vehicle operators was gathered during medical examinations and by questionnaire. First LBI during 7.5 years of follow-up was ascertained from insurance records. Hazard ratios and etiologic fractions were analyzed with Cox regression models stratified by injury severity and controlling for age, sex, height, weight, ethnicity, and biomechanical and psychosocial job factors. Severe LBI was defined as medically diagnosed postlaminectomy syndrome, spinal stenosis, herniated lumbar disc, sciatica, or spinal instability.

RESULTS

An exponential dose-response relationship was found between weekly driving hours and incidence of first LBI. Indicators of physical workload were more strongly associated with more severe low back injuries compared to less severe injuries. Rates of severe LBI increased 39% for every 10-hr increase in weekly driving (hazard ratio 1.39, 95% confidence interval 1.15-1.68). Higher risks of severe LBI were also found among operators performing heavy physical labor on cable cars (hazard ratio 2.76, 95% confidence intervals 1.24-6.14) or reporting more ergonomic problems at baseline (HR for upper quartile 1.65 (95% confidence interval 1.08-2.50). Estimates of etiologic fractions suggest that reduction of ergonomic problems to the low level currently experienced by 25% of drivers would result in a 19% reduction of severe LBI among all drivers. A change from full- (more than 30 hr) to part-time driving (20-30 hr) could reduce the number of severe LBI by 59%, although this gain would be reduced to 28% at the company level if injuries expected among additional employees, hired to maintain full service are included.

CONCLUSIONS

Duration of professional driving and ergonomic problems are independent and preventable risk factors for LBI even after adjustment for psychosocial factors.

Investigating risk factors for chronicity: the importance of distinguishing between return-to-work status and self-report measures of disability

OBJECTIVE

The objective of this study was to examine whether the outcome of psychosocial risk factor analyses varied as a function of whether the outcome variable was return-to-work status or self-reported functional disability.

METHODS

Participants were 255 workers who sustained a soft tissue injury to the back and participated in a community-based secondary prevention program. Assessment of psychologic risk factors (pain severity, pain catastrophizing, fear of movement/reinjury, depression) was conducted at pretreatment.

RESULTS

Logistic regression revealed that pain catastrophizing (odds ratio [OR], 0.53; 95% confidence interval [CI] = 0.32-0.88) and pain severity (OR, 0.65; 95% CI = 0.45-0.94) were significant predictors of return to work. However, when change in self-reported disability was used as the outcome variable, none of the psychosocial risk factors emerged as significant predictors.

CONCLUSIONS

Given the important theoretical, clinical, and policy implications of the outcome of risk factor research, more research is needed to further clarify the respective advantages and limitations to using self-reported versus return to work-based measures of disability.

Etiology of low back pain in athletes

Low back pain and injury is a common affliction for patients involved in athletic endeavors. For this reason, the health care professional should be cognizant of age-related and sports-specific considerations when evaluating athletes with low back complaints. An elevated index of suspicion with regard to specific etiologies of back pain proves invaluable in order to avoid the misdiagnosis of a more serious problem. Although a number of conditions exist that require more aggressive evaluation and treatment, the majority of low back pain in athletes is self-limiting. In this context, a treatment plan designed to increase low back and abdominal muscle strength, flexibility, and range of motion often proves beneficial not only in returning the athlete to competition, but also in preventing injury recurrence.

Are components of a comprehensive medical assessment predictive of work disability after an episode of occupational low back trouble?

STUDY DESIGN

One hundred fifty-nine subacute low back work-injured patients completed a full medical assessment at baseline. A full repeat examination was performed 3 months later, when return-to-work status was determined.

OBJECTIVE

To determine the prognostic value of a comprehensive medical assessment for the prediction of return-to-work status.

SUMMARY OF BACKGROUND DATA

A systematic review of the work disability prediction literature of low back trouble prognosis revealed that no high-quality studies included a full medical history and physical examination in the design. The results of studies included in the systematic review were equivocal with respect to predictive usefulness of medical variables.

METHODS

Participants completed medical history questionnaires and then were clinically examined by one of six experienced examiners (three physicians and three physiotherapists). Return-to-work status was measured 3 months later, and predictive validity was evaluated using logistic regression modeling.

RESULTS

Medical variables (, medical history subscales, physical examination subscales, and lumbar range-of-motion tests) showed modest correct classification rates varying between 61.6% and 69.1% for participants.

CONCLUSIONS

Comprehensive medical assessments play a crucial role in the early identification of serious pathology after low back trouble. We were unable to identify, however, any medical evaluation variables that would account for significant proportions of variance in return to work. The weight of evidence obtained in this study suggests that injured workers' subjective interpretations and appraisals may be more powerful predictors of the course of postinjury recovery than exclusively medical assessments.

Electromyography as a measure of peak and cumulative workload in intermediate care and its relationship to musculoskeletal injury: an exploratory ergonomic study

Injury rates in Intermediate Care (IC) facilities are high and the factors related to these injuries are unclear. The objectives of this exploratory sub-study, which is part of a large multi-faceted study in 8 IC facilities are to: (1) evaluate EMG measured over a full-shift in the back and shoulders of 32 care aides (CAs) as an indicator of peak and cumulative workload (n = 4 x 8 facilities); investigate the relationship between EMG measures and injury indicators; and explore the relationship between EMG measures and other workload measurements. Lumbar EMG was converted to predicted cumulative spinal compression and ranged in CAs from 11.7 to 22.8 MNs with a mean of 16.4 MNs. Average compression was significantly different during different periods of the day (p < 0.001) with highest compression during pre-breakfast when CAs assist most with activities of daily living. Significant differences were found in average compression between low and high injury facilities for 3 of 5 periods of the day (p < 0.010). Peak compressions exceeding 3400 N occurred for very little of the workday (e.g. 11.25s during the 75 min period pre-breakfast). Peak neck/shoulder muscle activity is low (99% APDF ranged from 8.33% to 28% MVC). Peak and cumulative spinal compression were significantly correlated with lost-time and musculoskeletal injury rates as well as with total tasks observed in the CAs (p < 0.01). Perceived exertion was only correlated with peak compressions (p < 0.01). Facilities with low injury rates provided significantly more CAs (p < 0.01) to meet resident needs, and subsequently CAs performed fewer tasks, resulting in less peak and cumulative spinal loading over the day.

Return to play after lumbar spine conditions and surgeries

Low back pain in athletes can result from a wide variety of conditions. A detailed history and physical examination supplemented by appropriate imaging studies can lead to an accurate diagnosis. The majority of cases will be self-limiting and resolve within 6 weeks regardless of treatment, but it is important to be able to identify conditions that require specific treatment. The decision of when an athlete can return to active competition is determined by the specific condition, associated symptoms, and treatment provided. Most athletes can return to full unrestricted play after sufficient resolution of pain and restoration of range of motion. Athletes undergoing spinal fusion are typically restricted from full-contact sports.

When to operate on abdominal gunshot wounds

Historically, penetrating abdominal trauma was managed expectantly until the late 19th century. In World War I, with the high mortality and morbidity associated with penetrating abdominal trauma, operative management replaced expectant management. It was soon realized that not all penetrating abdominal injuries required an operation. Since the 1960's, selective nonoperative management of stab wounds to the anterior abdomen has become the standard of care. However, gunshot wounds to the abdomen are still treated by mandatory exploration based on an allegedly high incidence of intra-abdominal injuries and low rate of complications, if laparotomy turns out negative. A number of series have recently surfaced, reporting successful outcomes, while decreasing morbidity and hospital length of stay, with selective non-operative management of gunshot wounds to the abdomen. This review will address the current controversies surrounding selective nonoperative management of gunshot wounds to the abdomen and will present our experience and current approaches.

Lower back and elbow injuries in golf

Golf injuries to the lower back and elbow are common problems in both the professional and amateur player, and any information regarding the successful treatment of these injuries has important implications for the medical practitioner. This paper presents the successful management and outcome of two case studies associated with low back pain and lateral epicondylitis in golf. Exercise therapy and conditioning has been shown to be an effective treatment modality for these two types of injury. In particular, a dynamic exercise programme which incorporates golf functional rehabilitation, is a modern and accepted method by both the patient and the clinician. Effective programmes need to be golf-specific to maintain the interest of the participant and yet at the same time they need to be able to accommodate other factors such as age, gender and the level of the golfer. Furthermore, it is critical that the clinical practitioner has a fundamental knowledge of normal swing mechanics and a working knowledge of the musculoskeletal requirements needed to swing a golf club. In the case of the lower back injury, evaluation was based on detailed computer tomography and centred on the conditioning of the transversus abdominis muscle. Although this muscle is not considered to be paraspinal, it has particularly important implications in the maintenance of spinal stability so that other more specific golf functioning exercises and rehabilitation can be performed. For the case study of lateral epicondylitis detailed evaluation and consideration of neuropathy was an important factor in the diagnostic process. In part, it was necessary to deviate from conventional treatment to produce an effective outcome. A comprehensive resistance-strength-training programme and golf functional 'hitting' programme was used to treat the problem. The conformity by the patient to complete the exercise regimen has been an issue of concern for clinicians managing and treating golf-related problems. Many golfers are 'fanatical' and unless they can see that by continuing the programme their injury will be overcome, it is difficult trying to restrict their time on the golf course. The two case studies described in this article highlight how an extensive and dynamic golf functional programme could be used as an effective method for managing and preventing golf injuries.

Low back pain in the adolescent athlete

There are several other entities such as infection, tumors, and fractures that I have not covered in this article. These entities are not common in adolescent athletes but must always be considered when athletes do no respond to typical treatment protocols for the problems I have discussed. The most important theme to take from this article is that low back pain in adolescent athletes is a problem that should not be ignored but instead fully evaluated because structural problems are quite common in this patient population.

Sensitivity and specificity of the indicators of sincere effort of the EPIC lift capacity test on a previously injured population

STUDY DESIGN

Randomized control post-test only.

OBJECTIVES

To investigate the reliability and validity of the EPIC Lift Capacity test's indicators of sincere effort.

SUMMARY OF BACKGROUND DATA

The EPIC Lift Capacity test (ELC) (Employment Potential Improvement Corp., Santa Ana, CA) is a functional evaluation tool used to identify physical limitations involved in lifting and manual materials handling. Identification of insincere effort is an integral component of such functional testing because of the potential secondary gain issues surrounding the various populations typically involved in this form of testing. The purpose of this study was to determine the sensitivity and specificity of the "indicators of sincere effort" of the EPIC Lift Capacity test when used on a previously injured population typical of subjects for which the test is designed.

METHODS

Subjects consisted of 41 volunteers (age 22 to 58 years) with a previously diagnosed musculoskeletal pathology of the spine or extremities. Volunteers were randomized into either the control group, instructed to give a sincere maximum effort, or the experimental group, instructed to give an insincere effort at 50% of their perceived maximum effort. All tests were administered by certified clinical evaluators according to the standardized EPIC Lift Capacity test protocol.-

RESULTS

Overall accuracy in identifying participants' level of effort was 86.84%. The indicators of valid effort exhibited both high positive (94.44%) and negative (80.00%) predictive values. The indicators of valid effort accounted for 94.9% of the total variance in the determination of the subjects' overall effort level. Interrater reliability for agreement of subjects' overall effort was good (interclass correlation coefficient = 0.82).

CONCLUSIONS

Through use of standardized indicators of sincere effort, certified EPIC Lift Capacity test evaluators were able to predict sincerity of effort with a high degree of reliability and validity. The rater's systematicobservational evaluation of effort was shown to be the single best indicator of sincere effort.

Females exhibit shorter paraspinal reflex latencies than males in response to sudden trunk flexion perturbations

BACKGROUND

Females have a higher risk of experiencing low back pain or injury than males. One possible reason for this might be altered reflexes since longer paraspinal reflex latencies exist in injured patients versus healthy controls. Gender differences have been reported in paraspinal reflex latency, yet findings are inconsistent. The goal here was to investigate gender differences in paraspinal reflex latency, avoiding and accounting for potentially gender-confounding experimental factors.

METHODS

Ten males and ten females underwent repeated trunk flexion perturbations. Paraspinal muscle activity and trunk kinematics were recorded to calculate reflex latency and maximum trunk flexion velocity. Two-way mixed model analyses of variance were used to determine the effects of gender on reflex latency and maximum trunk flexion velocity.

FINDINGS

Reflex latency was 18.7% shorter in females than in males (P=0.02) when exposed to identical trunk perturbations, and did not vary by impulse (P=0.38). However, maximum trunk flexion velocity was 35.3% faster in females than males (P=0.01) when exposed to identical trunk perturbations, and increased with impulse (P<0.01). While controlling for differences in maximum trunk flexion velocity, reflex latency was 16.4% shorter in females than males (P=0.04).

INTERPRETATION

The higher prevalence of low back pain and injury among females does not appear to result from slower paraspinal reflexes.

Wrestling and sports medicine

The coverage of wrestling events from the perspective of medical personnel is reviewed here. Considerations are made regarding the role of medical personnel, the supplies that are important for wrestling event coverage, and the injuries that are frequently encountered in wrestling. Attention is given to treatment of injuries and conditions that are largely specific to wrestling.

Diagnostic and management procedures for compensable back injuries without serious associated injuries. Modeling of the 1991 injury cohort from a major Michigan compensation insurer

STUDY DESIGN

A retrospective cohort of 2425 workers with compensated back conditions was created from the 1991 compensated cohort of the largest compensation insurer in Michigan by linking computerized information on social and demographic factors, diagnostic and management procedures, and cumulative missed worktime.

OBJECTIVE

To describe medical care use from date of injury in 1991 to mid-1993 by type of back condition, to identify factors affecting this use, to determine the effect of alternative model selection strategies on identifying such factors, to investigate the timing of surgery and the use of diagnostic studies in patients with displaced or herniated discs with and without surgery, and to compare the use of medical care in the study group with that recommended by national expert panels.

SUMMARY OF BACKGROUND DATA

Despite the enormous costs involved in medical care for patients with work-related back injuries, almost no information on the use of medical care is available for compensated back injuries by diagnostic and procedure code.

METHODS

Use of medical care was grouped into 18 categories for tabulation. Factors affecting use of medical care were identified by logistic regression, supplemented by Cox analysis for time to first procedure. The Hosmer-Lemeshow chi-square statistic was compared with the Bayes Information Criterion for evaluating model fit. Overall model utility was evaluated by comparing receiver operating characteristic curves generated by the model. For patients with displaced or herniated discs, algorithms were used to identify the diagnostic procedures performed before and after the first surgery and the amount of time that passed before each procedure was performed.

RESULTS

In patients with diagnoses of disc displacement or herniation or vertebrogenic neuritis, approximately 80% underwent radiography to obtain plain views of the spine, 75% underwent diagnostic imaging, 45% underwent electrodiagnostic procedures, and 24% underwent spinal surgery (29.3% had surgical procedures among those with disc conditions). In patients with diagnoses of back sprain or other symptomatic diagnoses, the percentages for the first three procedures are approximately 70%, 12%, and 12%, respectively. Diagnostic category, age, gender, and cumulative missed worktime predicted the receipt of diagnostic and treatment procedures. Women were 30% less likely to undergo computed axial tomography or magnetic resonance imaging and 50% less likely to undergo spinal surgery. Median time to spinal surgery was twice as long in the group that underwent diagnostic imaging and electrodiagnostic testing before surgery (134.5 days). Of the 622 patients with disc displacement/herniation, 510 (approximately 80%) had initial diagnostic imaging studies, and, of the 510, 162 (approximately 30%) had surgery. Thirteen (8%) were reoperated. Of the 162 patients who had surgery, 46 (approximately 30%) had follow-up diagnostic imaging, and, of the 46, nine (approximately 20%) were reoperated. Of the 348 managed conservatively, 96 (approximately 30%) had follow-up diagnostic imaging.

CONCLUSIONS

The data suggest only modest differences in the use of medical care between this study group and noncompensated study populations from previous reports. The authors of this study estimate that 27% of diagnostic imaging studies and 43% of plain radiography of the spine could have been avoided if then available Canadian recommendations or current American, guidelines had been followed. The gender effect remains unexplained and needs to be investigated in additional studies. There was an increase of 6% in the use of surgery in compensated patients compared with the use of surgery in a recent American series involving traditional health insurance, but this may be associated with greater work disability in the compensated group. The results of the current study suggest that the use and reporting of model selection strategies and the use of receiver operati

When golf hurts: musculoskeletal problems common to golfers

Golfers most frequently report injuries to the low back, nondominant shoulder, and elbow. Injury patterns differ between elite and recreational golfers; professional and elite golfers tend to experience golf injury related to overuse while amateur golfers may experience injury related to adverse swing technique and overuse. Therapeutic interventions should include assessment and treatment of deficiencies in the kinetic chain and professional instruction to modify swing technique. Changes in the swing may include instruction in a more efficient technique or shortening the swing to decrease biomechanical forces affecting the injured area.

The management of stab wounds to the back

The management of stab wounds to the back is controversial. There are certain clear indications for exploratory laparotomy, but most cases require a diagnostic workup and a period of observation. In this article, different diagnostic modalities are presented, including local wound exploration, diagnostic peritoneal lavage, abdominal computed tomography (CT) scan, triple-contrast abdominal CT scan, and intravenous pyelography (IVP). Recommendations for management are given, with emphasis on abdominal CT scan and observation.

Primary identification of an abused child in dental office: a case report

Although the injuries of child abuse are many and varied, several types of injuries are common to abuse. Many of these injuries are within the scope of dentistry or easily observed by the dental professional in the course of routine dental treatment. The authors present a case of child abuse with multiple bruises. The child had been spanked in the previous night and the morning of the attendance by his mother. This case emphasized that all practitioners should be vigilant when patients present with abnormal injuries which may be the result of abuse and further investigation should be instigated.

Disabling spondyloarthrosis risk factors in valley of Mexico workers

BACKGROUND

The objective of this study was to describe the most prevalent physically disabling conditions for insured workers belonging to the Mexican Social Security Institute (IMSS) in the Valley of Mexico and to identify risk factors for disabling spondyloarthrosis.

METHODS

Retrospective cases and prevalent controls from IMSS clinics in the Mexico City metropolitan area were studied. Eighty cases were IMSS workers reporting disability due to spondyloarthrosis; 80 controls were active workers at the same workplace and shared the economic activity of the cases. The 1995 IMSS Disability Report was reviewed. From this report congenital conditions of the musculoskeletal system, obesity, history of trauma, and sociodemographic patient characteristics were assessed.

RESULTS

The most important risk factors were a history of spina bifida (odds ratio [OR] = 29.3, 95% confidence interval [95% CI] = 5.3-161; p = 0.0009), supernumerary vertebrae (OR = 21.3, 95% CI = 5.3-95; p = 0.0001), history of low back (lumbar) trauma (OR = 3.9, 95% CI = 1.9-8.3; p = 0.0004), flatfoot (OR = 11.7, 95% CI = 1.9-69, p = 0.02), and obesity (OR = 2.0, 95% CI = 1.06-4.03; p = 0.04).

CONCLUSIONS

A history of congenital deformity of the musculoskeletal system, spinal column trauma, and obesity were risk factors most associated with work disability due to spondyloarthrosis.

Treatment of sea urchin injuries

Sea urchin injuries can be sustained in a variety of environments in which U.S. Forces are operating, and familiarity with this uncommon injury can be useful. Injuries by sea urchin spines can occur during military activities close to rocky salt aquatic ecosystems via three mechanisms. The author describes these mechanisms and discusses the diagnosis, management, and treatment of sea urchin injuries.