Documents Akesson, Ingrid 2 results

"There is a serious lack of quantitative data regarding exposure–response relationships between occupational risk factors and musculoskeletal elbow and hand disorders. This paper explores such relationships in group-level data from our earlier cross-sectional studies.Prevalence of complaints (Nordic Questionnaire) and diagnoses (physical examination) were recorded in 19 groups of female workers (1891 individuals), and 8 groups of male workers (761 individuals), with highly similar work tasks within each group. Linear regression was performed on the group means of wrist postures and angular velocity (obtained by electrogoniometers), as well as muscular load (obtained using electromyography), recorded in representative sub-samples, and psychosocial exposure (Job Content Questionnaire). To tackle within-group variations in physical exposure, sensitivity analyses were performed by bootstrapping simulations, rendering confidence intervals.The sex-adjusted slope of the regression line (?) for wrist angular velocity vs. complaints during the past 7 days was 0.6%/(°/s), (95% CI 0.3–0.9), and for carpal tunnel syndrome (CTS) 0.2%/(°/s), (0.1–0.3). For palmar flexion, p50, ? over the past 7 days was 0.8%/° (0.4–1.2); for CTS 0.3%/° (0.1–0.5); ? for muscular activity p90: 0.9%/%MVE (0.3–1.6), and 0.3%/%MVE (?0.03–0.6) respectively and finally ? for muscular rest: ?1.2%/%time (?2.4–0.03) and ?0.5%/%time (?0.9 to ?0.01). Relationships were also demonstrated for low job control, job strain and isostrain. Women exhibited a higher prevalence of complaints than men.In conclusion, we have established quantitative exposure–response relationships between physical work load and elbow/hand disorders. Wrist angular velocity was the most consistent risk factor."

"The quantitative relationship between exposure to physical risk factors and upper extremity work-related musculoskeletal disorders (UE-WMSDs) is virtually unknown. To explore the variation, objective measurements were derived in 43 types of work (686 individuals), using goniometry for the wrists and electromyography (EMG) for the forearm extensor muscles.The variations due to work were great for wrist movements, wrist positions, muscular rest, as well as peak load, ranging 1.4-54 °/s (flexion velocity; 50th percentile), -30°-3° (flexion angle; 50th percentile), 0.2-23% of time, and 3.4-41% of maximal EMG (90th percentile), respectively. Even within work categories, e.g. "repetitive industrial", there were large variations for all measures. Hence, classification without measurements has limited value.Most low-velocity work was accompanied by much muscular rest; however, the low velocity for mouse-intensive computer-work meant very little rest.Technical measurements are suitable as exposure measures in epidemiological studies, as well as a base for decisions about interventions. The multidimensional character of exposure - wrist movements, wrist postures, muscular recovery, and peak load - has to be considered.Relevance to industryDirect measurements provide objective and quantitative measures of the main physical risk factors for UE-WMSDs, appropriate for estimating the risk, as well as giving priority to, and evaluating, interventions."