Association between wrist ratio and carpal tunnel syndrome: Effect modification by body mass index.

INTRODUCTION: Previous studies have reported higher wrist ratios (WR) related to carpal tunnel syndrome (CTS) but have not assessed effect modification by obesity and may have inadequately controlled for confounders. METHODS: Baseline data of a multicenter prospective cohort study were analyzed. CTS was defined by nerve conduction study (NCS) criteria and symptoms. RESULTS: Among the 1,206 participants, a square-shaped wrist was associated with CTS after controlling for confounders (prevalence ratio = 2.27; 95% confidence interval [95% CI], 1.33-3.86). Body mass index (BMI) was a strong effect modifier on the relationship between WR and both CTS and abnormal NCS results, with normal weight strata of rectangular versus square wrists = 8.18 (95% CI, 1.63-49.96) and 7.12 (95% CI, 2.19-23.16), respectively. DISCUSSION: A square wrist is significantly associated with CTS after controlling for confounders. Effect modification by high BMI masked the eightfold magnitude adjusted relationship seen between WR and CTS among normal weight participants. Muscle Nerve 56: 1047-1053, 2017.

Factors Associated With Truck Crashes in a Large Cross Section of Commercial Motor Vehicle Drivers.

OBJECTIVE: This large, cross-sectional study calculated prevalence of disorders and assessed factors associated with self-reported lifetime crashes. METHODS: Truck drivers (n = 797) completed computerized questionnaires reporting crashes, demographics, psychosocial factors, and other elements, as well as had taken measurements (eg, height, weight, serum, and blood pressure). RESULTS: Most drivers were male (n = 685, 85.9%), and the mean body mass index was 32.9 ±â€Š7.5  kg/m2 with 493 (61.9%) being obese. Many drivers (n = 326, 39.9%) experienced at least one, with 132 (16.6%) having multiple, lifetime, reportable crashes. Many factors were associated with crashes, including increasing age, increasing truck driving experience, male sex, alcohol, low back pain, heart disease, and feeling tense. The most consistent associations with crashes were pulse pressure, cell phone use, and feeling physically exhausted after work. CONCLUSIONS: Modifiable factors associated with self-reported crashes were identified. These suggest targeted interventions may reduce risks of crashes.

The NIOSH lifting equation and low-back pain, Part 1: Association with low-back pain in the backworks prospective cohort study.

OBJECTIVE: The aim of this study was to evaluate relationships between the revised NIOSH lifting equation (RNLE) and risk of low-back pain (LBP). BACKGROUND: The RNLE is commonly used to quantify job physical stressors to the low back from lifting and/or lowering of loads. There is no prospective study on the relationship between RNLE and LBP that includes accounting for relevant covariates. METHOD: A cohort of 258 incident-eligible workers from 30 diverse facilities was followed for up to 4.5 years. Job physical exposures were individually measured. Worker demographics, medical history, psychosocial factors, hobbies, and current LBP were obtained at baseline. The cohort was followed monthly to ascertain development of LBP and quarterly to determine changes in job physical exposure. The relationship between LBP and peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression. RESULTS: Point and lifetime prevalences of LBP at baseline were 7.1% and 75.1%, respectively. During follow-up, there were 123 incident LBP cases. Factors predicting development of LBP included job physical exposure (PLI and PCLI), history of LBP, psychosocial factors, and housework. In adjusted models, risk (hazard ratio [HR]) increased per-unit increase in PLI and PCLI (p = .05 and .02; maximum HR = 4.3 and 4.2, respectively). PLI suggested a continuous increase in risk with an increase in PLI, whereas the PCLI showed elevated, but somewhat reduced, risk at higher exposures. CONCLUSION: Job physical stressors are associated with increased risk of LBP. Data suggest that the PLI and PCLI are useful metrics for estimating exposure to job physical stressors.

The NIOSH lifting equation and low-back pain, Part 2: Association with seeking care in the backworks prospective cohort study.

OBJECTIVE: The aim of this study was to investigate the relationship between the revised NIOSH lifting equation (RNLE) and risk of seeking care for low-back pain (SC-LBP). BACKGROUND: The RNLE is commonly used to quantify low-back physical stressors from lifting/lowering of loads in workplaces. There is no prospective study on relationship between RNLE and SC-LBP. METHOD: A cohort of 258 incident-eligible workers from 30 diverse facilities was followed for up to 4.5 years. Job physical exposures were individually measured. Worker demographics, medical history, psychosocial factors, hobbies, and current low-back pain were obtained at baseline. The cohort was followed monthly to ascertain SC-LBP and quarterly to determine changes in physical exposure. Associations between SC-LBP and both the peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression. RESULTS: SC-LBP lifetime prevalence at baseline was 31.9%, and there were 24 incident cases during follow-up. Factors predicting SC-LBP included job physical exposure (PLI and PCLI), history of low-back pain, age, female gender, and lower body mass index. In adjusted models, risk (hazard ratio [HR]) increased per unit increase in PLI and PCLI (p = .03 and .02, and maximum HR = 23.0 and 21.9, respectively). Whereas PCLI suggested a continuous increase in risk with an increase in PCLI, the PLI showed elevated, though somewhat reduced, risk at higher exposures (HR = 14.9 at PLI = 6). CONCLUSION: Job physical stressors are associated with increased risk of SC-LBP. Data suggest that both the PLI and PCLI are useful metrics for estimating exposure to job physical stressors.

Study protocol title: a prospective cohort study of low back pain.

BACKGROUND: Few prospective cohort studies of workplace low back pain (LBP) with quantified job physical exposure have been performed. There are few prospective epidemiological studies for LBP occupational risk factors and reported data generally have few adjustments for many personal and psychosocial factors. METHODS/DESIGN: A multi-center prospective cohort study has been incepted to quantify risk factors for LBP and potentially develop improved methods for designing and analyzing jobs. Due to the subjectivity of LBP, six measures of LBP are captured: 1) any LBP, 2) LBP ≥ 5/10 pain rating, 3) LBP with medication use, 4) LBP with healthcare provider visits, 5) LBP necessitating modified work duties and 6) LBP with lost work time. Workers have thus far been enrolled from 30 different employment settings in 4 diverse US states and performed widely varying work. At baseline, workers undergo laptop-administered questionnaires, structured interviews, and two standardized physical examinations to ascertain demographics, medical history, psychosocial factors, hobbies and physical activities, and current musculoskeletal disorders. All workers' jobs are individually measured for physical factors and are videotaped. Workers are followed monthly for the development of low back pain. Changes in jobs necessitate re-measure and re-videotaping of job physical factors. The lifetime cumulative incidence of low back pain will also include those with a past history of low back pain. Incident cases will exclude prevalent cases at baseline. Statistical methods planned include survival analyses and logistic regression. DISCUSSION: Data analysis of a prospective cohort study of low back pain is underway and has successfully enrolled over 800 workers to date.

The WISTAH hand study: a prospective cohort study of distal upper extremity musculoskeletal disorders.

BACKGROUND: Few prospective cohort studies of distal upper extremity musculoskeletal disorders have been performed. Past studies have provided somewhat conflicting evidence for occupational risk factors and have largely reported data without adjustments for many personal and psychosocial factors. METHODS/DESIGN: A multi-center prospective cohort study was incepted to quantify risk factors for distal upper extremity musculoskeletal disorders and potentially develop improved methods for analyzing jobs. Disorders to analyze included carpal tunnel syndrome, lateral epicondylalgia, medial epicondylalgia, trigger digit, deQuervain's stenosing tenosynovitis and other tendinoses. Workers have thus far been enrolled from 17 different employment settings in 3 diverse US states and performed widely varying work. At baseline, workers undergo laptop administered questionnaires, structured interviews, two standardized physical examinations and nerve conduction studies to ascertain demographic, medical history, psychosocial factors and current musculoskeletal disorders. All workers' jobs are individually measured for physical factors and are videotaped. Workers are followed monthly for the development of musculoskeletal disorders. Repeat nerve conduction studies are performed for those with symptoms of tingling and numbness in the prior six months. Changes in jobs necessitate re-measure and re-videotaping of job physical factors. Case definitions have been established. Point prevalence of carpal tunnel syndrome is a combination of paraesthesias in at least two median nerve-served digits plus an abnormal nerve conduction study at baseline. The lifetime cumulative incidence of carpal tunnel syndrome will also include those with a past history of carpal tunnel syndrome. Incident cases will exclude those with either a past history or prevalent cases at baseline. Statistical methods planned include survival analyses and logistic regression. DISCUSSION: A prospective cohort study of distal upper extremity musculoskeletal disorders is underway and has successfully enrolled over 1,000 workers to date.

Justification for a minimal lift program in critical care.

This chapter reviews literature pertaining to patient-handling tasks spanning the areas of epidemiology, biomechanics, perceived stresses, education and training programs, and introduction of mechanical patient lifting devices. All findings agree that patient handling is inherently dangerous and has been attributed to the majority of injuries incurred by nursing personnel; however, most studies have been performed in hospitals or long term care settings, but have not been specific to the area of critical care. The critical care environment poses unique challenges for nursing personnel and therefore, to ergonomists.