Psychosocial work factors in new or recurrent injuries among hospital workers: a prospective study.

PURPOSE: Accumulating evidence suggests an important role for psychosocial work factors in injury, but little is known about the interaction between psychosocial factors and previous injury experience on subsequent injury risk. We examined the relationships between psychosocial work factors and new or recurrent injury among hospital workers. METHODS: We studied 492 hospital workers including 116 cases with baseline injury and 376 injury-free referents at baseline over follow-up. Job strain, total support, effort-reward imbalance, overcommitment, and musculoskeletal injury at baseline were examined in logistic regression models as predictors of new or recurrent injury experienced during a 2-year follow-up period. RESULTS: The overall cumulative incidence of injury over follow-up was 35.6 % (51.7 % for re-injury among baseline injury cases; 30.6 % for new injury among referents). Significantly increased risks with baseline job strain (OR 1.26; 95 % CI 1.02-1.55) and effort-reward imbalance (OR 1.42; 95 % CI 1.12-1.81) were observed for injury only among the referents. Overcommitment was associated with increased risk of injury only among the cases (OR 1.58; 95 % CI 1.05-2.39). CONCLUSIONS: The effects of psychosocial work factors on new or recurrent injury risk appear to differ by previous injury experience, suggesting the need for differing preventive strategies in hospital workers.

Meta-analysis: association between wrist posture and carpal tunnel syndrome among workers.

BACKGROUND: Carpal tunnel syndrome (CTS) is a common work-related peripheral neuropathy. In addition to grip force and repetitive hand exertions, wrist posture (hyperextension and hyperflexion) may be a risk factor for CTS among workers. However, findings of studies evaluating the relationship between wrist posture and CTS are inconsistent. The purpose of this paper was to conduct a meta-analysis of existing studies to evaluate the evidence of the relationship between wrist posture at work and risk of CTS. METHODS: PubMed and Google Scholar were searched to identify relevant studies published between 1980 and 2012. The following search terms were used: "work related", "carpal tunnel syndrome", "wrist posture", and "epidemiology". The studies defined wrist posture as the deviation of the wrist in extension or flexion from a neutral wrist posture. Relative risk (RR) of individual studies for postural risk was pooled to evaluate the overall risk of wrist posture on CTS. RESULTS: Nine studies met the inclusion criteria. All were cross-sectional or case-control designs and relied on self-report or observer's estimates for wrist posture assessment. The pooled RR of work-related CTS increased with increasing hours of exposure to wrist deviation or extension/flexion [RR = 2.01; 95% confidence interval (CI): 1.646-2.43; p < 0.01: Shore-adjusted 95% CI: 1.32-2.97]. CONCLUSION: We found evidence that prolonged exposure to non-neutral wrist postures is associated with a twofold increased risk for CTS compared with low hours of exposure to non-neutral wrist postures. Workplace interventions to prevent CTS should incorporate training and engineering interventions that reduce sustained non-neutral wrist postures.

The impact of posture on wrist tendinosis among blue-collar workers: the San Francisco study.

OBJECTIVE: The objective was to evaluate the effect of wrist posture on incidence of wrist tendinosis in a prospective cohort of blue-collar workers. BACKGROUND: Previous studies have identified awkward wrist posture as a risk factor for wrist tendinosis, though the magnitude of the relationship is unclear. METHOD: Workers (N = 413) at four industries were followed for up to 28 months with questionnaires and physical examinations every 4 months. Individualized exposure assessments of wrist posture were based on video analysis to determine the wrist extension/flexion angle for up to four tasks. Posture measures were calculated while in "heavy pinch" (> 1 kg force), "heavy power grip" (> 4 kg force), and across "all grips." A proportional hazards model estimated the relationship between time-weighted average posture measures and incidence of dominant-side wrist tendinosis. RESULTS: In a model based on tertiles of exposure, adjusted for age, gender, hand force, and repetition of exertions, risk of tendinosis more than doubled in the highest category (HR = 2.69, 95% CI = 1.01-7.21) across all grips. The relative risk was highest during heavy pinch (HR = 5.03, 95% CI = 0.74-34.05), though not statistically significant. Increased median wrist extension while in heavy power grip was protective (HR = 0.24, 95% CI = 0.06-0.94). CONCLUSION: In this study of production workers, median wrist flexion of more than 70, across all grips, was associated with an increased risk of tendinosis. The protective findings on median wrist extension during power grip deserve further investigation. Work tasks and tools should be designed to prevent sustained wrist flexion, especially during tasks involving forceful pinch.