An Evaluation of the Structural Validity of the Work Limitation Questionnaire Using the Rasch Model.

OBJECTIVE: To investigate the targeting, scaling, and structural validity of the Work Limitation Questionnaire (WLQ) using Rasch analysis. DESIGN: Secondary data analysis. SETTING: Tertiary care hospital. PARTICIPANTS: The data were sourced from an upper limb specialty clinic of injured workers using the convenience sampling method and from a national randomized controlled trial investigating 2 surgical options for rotator cuff repair by formal, randomized selection (N=315). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Work Limitation Questionnaire 25-item version (WLQ-25). The WLQ contains 25 items measuring a client's ability to perform specific job demands on a 5-point ordinal response scale ranging from 0 (difficulty none of the time) to 4 (difficulty all the time). The average of all 25 items is used as the total score, ranging from 0 to 4, where higher index scores indicate greater difficulty performing daily work. Subscales were used to assess time management, physical demands (PD), mental-interpersonal demands, and output demands. RESULTS: The Rasch analyses performed on the dataset included the test of fit of residuals, ordering of item thresholds, Person separation index, differential item functioning (DIF), dependency, and unidimensionality. The partial credit model was selected for the current Rasch analysis because the likelihood ratio test was significant at both the overall questionnaire and the subscale level (P<.001). The WLQ-25 did not fit with the Rasch model (χ2=1715.58; df=125; P<.001) and most of the thresholds were disordered. A series of steps were undertaken to improve the fit statistic, including item reduction (6 items) and response merging (9 items). DIF was absent in the revised scale based on sex, age, full- or part-time employment, and type of employment. Only 3 revised subscales, namely the PD, mental demands, and interpersonal demands subscales, demonstrated acceptable fit to the Rasch model. CONCLUSIONS: The WLQ-25 demonstrated substantial misfit from the Rasch model, which could not be fully mediated. The revised PD, mental demands, and interpersonal demands subscales could be used to assess these constructs.

Injuries in Australian Army full-time and part-time personnel undertaking basic training.

BACKGROUND: Musculoskeletal injuries are a problem in military personnel as they detract from force readiness and may prevent deployment. Injuries occur during basic training at three times the rate observed in post-training military service and more commonly in part time (PT) when compared to full time (FT) army personnel. The purpose of this study was to examine differences in rates and patterns of reported injuries between full time (FT) and part time (PT) personnel undertaking army basic training. METHODS: A retrospective cohort study was conducted to determine and compare rates and patterns of injuries which occurred during basic training in PT and FT personnel. Injury data from the period 01 July 2012 to 30 June 2014 was obtained in a non-identifiable format from the Workplace Health, Safety, Compensation and Reporting (WHSCAR) database of the Australian Department of Defence. Analysis included descriptive statistics and the calculation of injury rates and injury rate ratios. RESULTS: A total of 1385 injuries were reported across FT and PT cohorts, with an injury rate ratio for FT:PT of 1.06 [0.80-1.40], when accounting for exposure. In FT personnel, 1192 (90%) were Minor Personal Injuries (MPIs) and 43 (3.2%) Serious Personal Injuries (SPIs). In PT personnel, 147 (94.8%) were MPIs and three (1.9%) SPIs. In both FT and PT personnel, injuries most commonly: occurred during Physical Training (41.7% FT, 515 MPIs, 10 SPIs, 32% PT. 48 MPIs, 1 SPI); affected the knee (FT 41.7% 159 MPIs, 7 SPIs, PT 36.0%, 22 MPIs, 0 SPIs); involved soft tissue damage (FT 60.9%, 744 MPIs, 8 SPIs, PT 69.3%, 103 MPIs, 1 SPI); and were due to muscular stress (FT 41.7%, 509 MPIs, 6 SPIs, PT 36%, 54 MPIs, 0 SPIs). CONCLUSIONS: FT and PT recruits exhibited similar injury profiles, with mechanisms, sites and types of injuries in agreement with other research. Given these similarities, effective interventions that reduce injury risks in either population will likely benefit both.

Developing predictive models for return to work using the Military Power, Performance and Prevention (MP3) musculoskeletal injury risk algorithm: a study protocol for an injury risk assessment programme.

BACKGROUND: Musculoskeletal injuries are a primary source of disability in the US Military, and low back pain and lower extremity injuries account for over 44% of limited work days annually. History of prior musculoskeletal injury increases the risk for future injury. This study aims to determine the risk of injury after returning to work from a previous injury. The objective is to identify criteria that can help predict likelihood for future injury or re-injury. METHODS: There will be 480 active duty soldiers recruited from across four medical centres. These will be patients who have sustained a musculoskeletal injury in the lower extremity or lumbar/thoracic spine, and have now been cleared to return back to work without any limitations. Subjects will undergo a battery of physical performance tests and fill out sociodemographic surveys. They will be followed for a year to identify any musculoskeletal injuries that occur. Prediction algorithms will be derived using regression analysis from performance and sociodemographic variables found to be significantly different between injured and non-injured subjects. DISCUSSION: Due to the high rates of injuries, injury prevention and prediction initiatives are growing. This is the first study looking at predicting re-injury rates after an initial musculoskeletal injury. In addition, multivariate prediction models appear to have move value than models based on only one variable. This approach aims to validate a multivariate model used in healthy non-injured individuals to help improve variables that best predict the ability to return to work with lower risk of injury, after a recent musculoskeletal injury. TRIAL REGISTRATION NUMBER: NCT02776930.

Brooding as moderator of depressive symptoms after a work accident: A longitudinal study.

This study analyzes the relationship between having experienced a work accident and developing depressive symptoms six months later, considering the subjective severity of accidents, the use of both positive and negative religious coping strategies, and brooding as predictors variables. Fifty seven women and 187 men were evaluated during the month following their accident (T1) and six months later (T2). The results show that after controlling for initial depressive symptoms, all predictors showed a statistically significant relationship with depression at six months, including the interaction between brooding and subjective severity of accident. Forty nine percent of resilient participants exhibited low symptoms at T1 and T2, 22% of recovered individuals showed high symptoms at T1 and low symptoms afterwards, 20% of depressive individuals had high symptoms at T1 and T2, and 8% exhibited high symptoms only at T2. High severity, brooding and religious coping at T1 differentiated those who exhibited stable symptoms from those who were resilient. Resilience was specifically predicted with a negative coefficient by the interaction of brooding with subjective severity of accident. We conclude that brooding is a variable that moderates the relationship between subjective severity of accident and the development and maintenance of depressive symptoms. Subjective severity of accident, brooding and negative religious coping are risk factors, while positive religious coping is not a sufficient protection factor.

Surgical treatment of acute type V acromioclavicular joint dislocations in professional athletes: an anatomic ligament reconstruction with synthetic implant augmentation.

BACKGROUND: Most acromioclavicular (AC) joint injuries occur in men in their third decade of life during high-speed or high-impact body contact sports. The management of acute complete AC joint dislocation is surgical. Current surgical techniques include anatomic reconstruction of the main restraints of the AC joint and aim to improve functional outcomes and to reduce the complication rate. METHODS: We present 10 cases of acute type V AC joint dislocation in professional athletes treated surgically with anatomic reconstruction of the coracoclavicular and AC ligaments and augmentation with the use of a synthetic polyester tape. The minimum follow-up of the patients was 2 years (mean, 48 months; range, 24-86 months). The postoperative functional outcome was assessed at 1 year and 2 years using the Constant-Murley, American Shoulder and Elbow Surgeons, and modified University of California-Los Angeles scoring systems. RESULTS: In all cases, the postoperative scores were significantly improved (P < .005 in all comparisons with the preoperative scores), and all patients returned to their preinjury high level of activity 6 months postoperatively. Radiographs at 1 month and 6 months revealed the maintenance of reduction. There were no complications. CONCLUSION: According to the results of our series of patients, demanding cases of acute AC joint dislocation Rockwood type V, in professional athletes, require anatomic fixation of both coracoclavicular and AC ligaments for return to sports as soon as possible and at the preinjury level of performance.

Professional football can be considered a healthy sport?

PURPOSE: This study aimed to compare the results of knee MRIs of former football players with no previous knee surgeries with non-regular practitioners of impact sports, matched by age and sex, and combine these results with other variables such as current quality of life and pain in the knees. METHODS: The study participants were 16 male former professional football players and 21 male volunteers from different non-sports professional areas. All participants underwent bilateral magnetic resonances. Specific knee evaluations with regard to osteoarthritis and quality of life were performed in both groups by applying the Knee Injury and Osteoarthritis Outcome Score (KOOS) subjective questionnaires and SF-36, respectively. RESULTS: The between-group comparison revealed significant differences on: pain, symptoms, and quality of life related to the knee in KOOS subscales; physical aspects and vitality subscale of SF-36; and former soccer players had worst magnetic resonances scores than controls. CONCLUSION: Results of this study indicate probable specific adverse effects associated with participating in professional football. LEVEL OF EVIDENCE: Cross-sectional study, Level III.

The Relationship Between Functional Movement, Balance Deficits, and Previous Injury History in Deploying Marine Warfighters.

Screening for primary musculoskeletal injury (MSK-I) is costly and time-consuming. Both the Functional Movement Screen (FMS) and the Y-Balance Test (YBT) have been shown to predict future MSK-I. With a goal of optimizing the efficiency of primary MSK-I screening, we studied associations between performance on the FMS and YBT and whether history of MSK-I influenced FMS and YBT scores. In total, 365 deploying Marines performed the FMS and YBT as prescribed. Composite and individual scores were each categorized as high risk or low risk using published injury thresholds: High-risk FMS included composite scores ≤14 and right-to-left (R/L) asymmetry for Shoulder Mobility, In-Line Lunge, Straight Leg Raise, Hurdle Step, or Rotary Stability. High-risk YBT consisted of anterior, posteromedial, and/or posterolateral R/L differences >4 cm and/or composite differences ≥12 cm. Pearson's χ tests evaluated associations between: (a) all FMS and YBT risk groups and (b) previous MSK-I and all FMS and YBT risk groups. Marines with high-risk FMS were twice as likely to have high-risk YBT posteromedial scores (χ = 10.2, p = 0.001; odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.3-3.2). History of any MSK-I was not associated with high-risk FMS or high-risk YBT. However, previous lower extremity MSK-I was associated with In-Line Lunge asymmetries (χ = 9.8, p = 0.002, OR = 2.2, 95% CI = 1.3-3.6). Overall, we found limited overlap in FMS and YBT risk. Because both methods seem to assess different risk factors for injury, we recommend FMS and YBT continue to be used together in combination with a thorough injury history until their predictive capacities are further established.

Examining outcome of early physician specialist assessment in injured workers with shoulder complaints.

BACKGROUND: There is minimal research on demographics, type of injury and diagnosis of injured workers with shoulder problems. The purposes of this study were: 1) to document the demographics of patients with shoulder complaints referred to an Early Shoulder Physician Assessment (ESPA) Program and to describe the recommended management, and 2) to examine the relationship between patient characteristics and their subjective complaints of pain and functional difficulty. METHODS: This study involved a retrospective review of electronic files of injured workers mostly seen within the first 16 weeks of injury or recurrence. Measures of functional difficulty and pain were the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) and Numeric Pain Scale (NPS). RESULTS: Files of 550 consecutive patients, 260 females (47%), 290 men (53%) were examined. The average age was 49 (SD = 11, range 22-77), with 28 (5%) patients being 65 years of age or older. Patients who were not working were the most disabled group based on Quick DASH (F = 49.93, p < 0.0001) and NPS (F = 10.24, p = 0.002). Patients who were working full time performing regular duties were the least disabled according to both measures, the QuickDASH (F = 10.24, p = 0.002) and NPS (F = 7.57, p = 0.006). Patients waiting more than 16 weeks were slightly older (53 years of age vs. 49, p = 0.045) than those who met the criteria for early assessment with similar levels of pain and functional difficulty. Biceps pathology had the highest prevalence (37%). Full thickness tear had a prevalence of 14%. Instability, labral lesions and osteoarthritis of glenohumeral joint were uncommon conditions (3, 2 and 1% respectively). Fifty-five patients (10%) were surgical candidates and had higher scores on QuickDASH (F = 7.16, p = 0.008) and NPS (F = 4.24, p = 0.04) compared to those who did not require surgery. CONCLUSIONS: This study provides information on characteristics and prevalence of important variables in injured workers with shoulder problems and highlights the impact of these characteristics on pain and disability.

Reported load carriage injuries of the Australian army soldier.

INTRODUCTION: Many injuries experienced by soldiers can be attributed to the occupational loads they are required to carry. PURPOSE: The aim of this study was to determine whether contemporary military load carriage is a source of injuries to Australian Regular Army soldiers and to profile these injuries. METHODS: The Australian Defence Force 'Occupational Health, Safety and Compensation Analysis and Reporting' database was searched to identify all reported injuries sustained during load carriage events. Key search terms were employed and narrative description fields were interrogated to increase data accuracy. RESULTS: A total of 1,954 injury records were extracted from the database. Of these, 404 injuries were attributed to load carriage. The majority of these load carriage injuries involved either the lower limb or back, with bones and joints accounting for the most frequently reported body structures to be injured. Field activities were the leading activities being performed at the time that load carriage injuries occurred, and muscular stress was identified as the mechanism of injury for over half of reported load carriage injuries. CONCLUSION: This study suggests that load carriage is a substantial source of injury risk to Australian Army soldiers. Physical training may fail to adequately prepare soldiers for load carriage tasks during field training exercises.

Load Carriage: An Integrated Risk Management Approach.

Military load carriage (LC) gives rise to substantial risks to soldier health, tactical performance, and mission success. The aim of this article was to extract and synthesize the key findings of a series of LC research reports previously published by the authors. Five reviews and 6 studies were included, with key findings extracted and synthesized in tabulated and critical narrative form. The weight of a soldier's load is a source of risk for soldier's injuries and tactical task performance. The resulting level of risk is influenced by risk modifiers (like speed of march, terrain grade, and task type and duration) and risk controls (like administrative controls and physical conditioning). In the Australian context, these risk controls were limited, with soldiers carrying heavier loads than those mandated by doctrine and policy, and LC conditioning not meeting best practice. The diversity of LC contexts, combined with the influence of risk modifiers and risk controls, means that levels of risk associated with LC are not consistent and must be assessed on a case-by-case basis. Load weight and marching routes (terrains, gradients), distances, speed, and duration are all potentially treatable sources of LC-related risk. Potential risk treatments include not only commanders directly addressing these specific sources of risk to the extent feasible, on a case-by-case basis, when planning or conducting LC tasks but also improving administration controls (i.e., doctrine and policies) and personal protection (i.e., the physical conditioning of the soldier) as part of the hierarchy of controls. Practical application would involve commanders developing and implementing dedicated LC doctrine and policies and implementing and enforcing LC conditioning programs that meets best practice.

Physiological and Medical Aspects That Put Women Soldiers at Increased Risk for Overuse Injuries.

Anthropometric and physiological factors place female soldiers at a disadvantage relative to male soldiers in most aspects of physical performance. Average aerobic and anaerobic fitness levels are lower in women than in men. Thus, women have a lower overall work capacity and must exert themselves more than men to achieve the same output. The lower weight and fat-free mass and the higher body fat of women are associated with lower muscle strength and endurance, placing them at a disadvantage compared with men in performing military tasks such as lifting and carrying weights, or marching with a load. Working at a higher percentage of their maximal capacity to achieve the same performance levels as men, women tire earlier. Their smaller size, skeletal anatomy, and different bone geometry also predispose women to a higher incidence of exercise-related injuries. Consequently, the attrition rate of female soldiers in combat units is higher than that of their male counterparts. This review summarizes the literature on gender-related physiological and anatomical differences that put female soldiers at an increased risk of exercise-related injuries.

[Plaque-like leiomyomas on a chemical burn: First case report]. / Léiomyomes en plaque sur brûlure chimique : première observation.

BACKGROUND: Cutaneous leiomyomas are uncommon benign smooth muscle neoplasms of skin of unknown pathogenesis. We report a sporadic case of multiple cutaneous leiomyomas at the site of a chemical burn. OBSERVATION: A 47-year-old male presented with multiple grouped red nodules on the right calf painful to cold and to touch. The lesions were located on the site of a chemical wound that had occurred 5 years earlier. Histopathological examination revealed a proliferation of smooth muscle fibres, leading to diagnosis of leiomyoma. DISCUSSION: To our knowledge, the literature contains no previous reports of sporadic multiple cutaneous leiomyomas occurring at a chemical burn site. While a chance association cannot be ruled out, there is also the possibility of a physiopathological mechanism similar to that of vascular tumours following exposure to 4-hydrazinobenzoic acid. This compound, a hydrazine derivative of the fungus Agaricus bisporus, can cause smooth-muscle tumours in the aorta and large vessels with morphological characteristics similar to those seen in vascular leiomyomas.

A preliminary report of acute and subacute arthroscopic repair of the radial ulnohumeral ligament after elbow dislocation in the high-demand patient.

PURPOSE: The purpose of this study was to evaluate functional outcomes, range of motion (ROM), elbow stability, and time to return to full activities after acute and subacute arthroscopic repair of a simple elbow dislocation in high-demand patients. METHODS: "High-demand patients" were defined as in-season athletes and individuals who required use of both hands for their profession and believed that they could not miss the 6 weeks of work that may be required with conservative treatment in an elbow brace. We retrospectively reviewed 14 consecutive patients with a simple elbow dislocation who underwent arthroscopic repair of the radial ulnohumeral ligament from 2008-2012. Outcomes measures included the Mayo Elbow Performance Score (MEPS), elbow ROM, elbow stability, and time to return to full activities. Each patient was contacted once by telephone to determine the current activity level and presence of any pain or functional limitations. RESULTS: The mean patient age was 25 years, with telephone follow-up at a mean of 30 months and clinical examination after a minimum of 6 months. The postoperative MEPS was excellent (mean, 99.6; range, 95 to 100) for all 14 patients, and all returned to their preinjury level of function with no restrictions or instability. Final ROM averaged -3° of full extension to greater than 130° of flexion. The mean time to return to full activities in and out of a brace was 2.7 weeks and 6.6 weeks, respectively, in the acute group and 4.6 weeks and 8.9 weeks, respectively, in the subacute group. All patients were satisfied with their outcome. CONCLUSIONS: Conservative management remains the gold standard for most simple elbow dislocations. We believe that certain high-demand patients may be candidates for acute arthroscopic ligamentous repair. Our preliminary data show that acute arthroscopic repair of the radial ulnohumeral ligament is a safe, effective procedure that restores stability to the elbow and allows patients to quickly return to full activities. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Development of three-dimensional shoulder kinematic and electromyographic exposure variation analysis methodology in violin musicians.

A total of 11 male and 19 female violinists performed 30-second random-ordered slow and fast musical repertoire while right shoulder three-dimensional kinematic, and upper trapezius and serratus anterior surface electromyography (EMG) data were summarised using exposure variation analysis (EVA), a bivariate distribution of work time spent at categories of signal amplitude, and duration spent at a fixed category of amplitude. Sixty-two per cent of intraclass correlation coefficients [1,1] for all kinematic and EMG variables exceeded 0.75, and 40% of standard error of the measurement results were below 5%, confirming EVA reliability. When fast repertoire was played, increases in odds ratios in short duration cells were seen in 23 of 24 possible instances, and decreases in longer duration cells were seen in 17 instances in all EVA arrays using multinomial logistic regression with random effects, confirming a shift towards shorter duration. A reliable technique to assess right shoulder kinematic and EMG exposure in violinists was identified. PRACTITIONER SUMMARY: A reliable method of measuring right shoulder motion and muscle activity exposure variation in violinists was developed which can be used to assess ergonomic risk in other occupations. Recently developed statistical methods enabled differentiation between fast and slow musical performance of standardised musical repertoire.

[Acromioclavicular injuries in professional athletes]. / Schultereckgelenksprengung bei Profisportlern.

BACKGROUND: Acromioclavicular joint (ACJ) dislocations represent the most frequent injuries of the shoulder girdle among athletes. Low grade injuries are more common than high grade injuries. Possible injury mechanisms are either a direct trauma to the shoulder or a fall on an adducted elbow with indirect trauma to the ACJ. DIAGNOSTICS: Accurate radiological diagnostics, including stress recordings for detection of a horizontal instability component are of utmost importance and allow correct classification of the ACJ injury. THERAPY: Most ACJ injuries can be treated non-operatively with short-term immobilization, oral analgesia therapy and pain-oriented functional physiotherapeutic treatment. In principle, surgical indications are high grade injuries in the sense of Rockwood dislocations types IV and V; however, individual factors, such as the type of sport, handedness, career perspectives and economic aspects have to be involved in the decision-making process, particularly in professional athletes. Acute ACJ dislocations are treated arthroscopically including coracoclavicular and additional acromioclavicular stabilization in cases of horizontal instability. Chronic ACJ dislocations require coracoclavicular ligament reconstruction using autologous semitendinosus tendon grafting. PERSPECTIVES: After relatively restrictive postoperative care including a 6-week immobilization period, competitive sport is normally possible after 3-4 months in cases of acute injury and after 6 months in cases of chronic injury.

[Shoulder injuries in golf]. / Schulterverletzungen im Golfsport.

BACKGROUND: Due to its growing popularity golf has now come into the focus of orthopedic sports medicine. With a wide range of age groups and playing levels, orthopedic surgeons will encounter a wide range of musculoskeletal problems which are usually the result of overuse rather than trauma. ANATOMY: The shoulder joint plays an important role in the golf swing whereby not only the muscles around the glenohumeral joint but also the scapula stabilizing muscles are extremely important for an effective golf swing. INJURY PATTERNS: Golf is strictly not considered to be an overhead sport; however, the extreme peak positions of the golf swing involve placing the shoulder joint in maximum abduction and adduction positions which can provoke impingement, lesions of the pulley system or even a special form of posterior shoulder instability. PERSPECTIVES: Even after complex shoulder operations, such as rotator cuff repair or shoulder arthroplasty, a return to the golf course at nearly the same level of play can be expected.

Professional fighters brain health study: rationale and methods.

Repetitive head trauma is a risk factor for Alzheimer's disease and is the primary cause of chronic traumatic encephalopathy. However, little is known about the natural history of, and risk factors for, chronic traumatic encephalopathy or about means of early detection and intervention. The Professional Fighters Brain Health Study is a longitudinal study of active professional fighters (boxers and mixed martial artists), retired professional fighters, and controls matched for age and level of education. The main objective of the Professional Fighters Brain Health Study is to determine the relationships between measures of head trauma exposure and other potential modifiers and changes in brain imaging and neurological and behavioral function over time. The study is designed to extend over 5 years, and we anticipate enrollment of more than 400 boxers and mixed martial artists. Participants will undergo annual evaluations that include 3-tesla magnetic resonance imaging scanning, computerized cognitive assessments, speech analysis, surveys of mood and impulsivity, and blood sampling for genotyping and exploratory biomarker studies. Statistical models will be developed and validated to predict early and progressive changes in brain structure and function. A composite fight exposure index, developed as a summary measure of cumulative traumatic exposure, shows promise as a predictor of brain volumes and cognitive function.

Measuring hazardous work and identifying risk factors for non-fatal injuries among children working in Philippine agriculture.

OBJECTIVES: Global consensus is lacking, especially among developing countries, on whether agricultural work is detrimental to children's health and safety. We aimed to measure the degree to which Philippine children working in agriculture have a higher risk of injury compared with children working in other industries, and to uncover potential risk factors for their non-fatal injuries. METHODS: Using the Philippine Survey of Children (SOC) 2001, we calculated injury incidence rates and relative risk measures across industries, and employed a multivariate logistic regression on the sample of working children in agriculture to ascertain the association of various exposures with the occurrence of work-related injuries. RESULTS: Children working in agriculture had a fivefold risk of non-fatal injury compared to children working in other industries. Logistic regression indicated that the most robust risk factor for the occurrence of non-fatal injury was the use of tools (OR = 3.12). CONCLUSIONS: The results of this study demonstrate agriculture to be a hazardous industry for children. Further research should focus on identifying the most dangerous tools and restricting their use.

Self-reported work-related musculoskeletal injuries and isometric handgrip strength.

BACKGROUND: Musculoskeletal injuries are common in car assembly workers, causing significant morbidity. There is evidence that increased muscle strength reduces musculoskeletal injury risk and that handgrip strength is a predictor of general muscle strength. Aims To investigate whether isometric handgrip strength (IHGS) is a predictor of increased musculoskeletal injury risk in automotive assembly workers. METHODS: We measured IHGS in a cross-sectional survey of final assembly line workers in an automotive manufacturing plant. Weak handgrip was defined as two standard deviations below the normative mean value for age and gender. Self-reported musculoskeletal injury/accident data and recent musculoskeletal symptoms were recorded using a modified Nordic musculoskeletal questionnaire. RESULTS: Of 445 final assembly line workers, 206 (46%) participated. Sixty participants (29%) reported a musculoskeletal injury/accident at work in the preceding 5 years. Mean IHGS in this population was lower than international normative values. Odds ratios for self-reported injury (adjusted for gender and recent musculoskeletal symptoms) were 0.62 (95% CI 0.28-1.35) for left weak handgrip and 0.57 (95% CI 0.31-1.1) for right weak handgrip. CONCLUSIONS: In this study, weak handgrip did not predict increased risk of musculoskeletal injuries/accidents.

The ratio of thoracic to lumbar compression force is posture dependent.

Despite the evidence suggesting that between 8% and 55% of manual labourers experience thoracic pain, research on spinal loading during occupational tasks has been almost invariably limited to the lumbar spine. In this study, we determined the ratio of thoracic to lumbar compression force and the relative risk of injury to each region in various postures. Compressive forces on the spine were calculated based on previously reported thoracic and lumbar intradiscal pressures and disc cross-sectional areas. Flexion postures were associated with an approximate doubling in lumbar compression force but only small increases (or even decreases) in thoracic compression. The ratio of thoracic to lumbar compression was above the tolerance ratio (i.e. the ratio of thoracic to lumbar compressive strength) during upright postures and below the tolerance ratio during flexion postures, indicating that upright postures may pose a greater relative risk of injury to the thoracic spine than to the lumbar spine. Practitioner summary: Previously reported thoracic and lumbar in vivo disc pressures during various postures were compared. The ratio of thoracic and lumbar compression increased during upright postures and decreased in flexed postures, indicating that upright postures may pose a greater risk of injury to the thoracic spine than to the lumbar spine.