Documents Wang, Mao-Jiun J. 3 results

"Psychosocial factors, individual factors, workplace requirements, and workplace organizational factors have all been reported as being associated with the risk of musculoskeletal disorders [11]. Huang, Feuerstein, and Sauter [5] described the various concepts and models proposed to link occupational stress and work-related upper extremity disorders, as well as the difficulty in verifying the suggested linkages. Huang et al. [5] suggested that decomposing a complex model would be an appropriate method to begin the investigations of the proposed models. Task repetition is a workplace requirement that is considered a potential risk factor for cumulative trauma and its relationship to psychosocial factors was investigated. The study found only weak to no statistically significant relationship between task repetition and reported psychosocial factors of job stress in workers in Taiwan."

"This study evaluated screwdrivers with different handle designs and blade lengths. 10 men and 10 women voluntarily participated. A repeated-measures experiment design was employed. The three independent factors were sex of user, handle (four types), and blade length (130, 170, and 210 mm). The dependent measures were the maximum supination torque under a static task and the %MVC of EMG responses in biceps brachii and flexor digitorum, and a discomfort rating for the upper extremity under the dynamic task. Analysis showed that the in-line screwdriver with the combined characteristics of large handle diameter (3.8-4.1 cm), smooth rubber covering handle surface, triangular (or circular) shape, and adequate handle length (11 cm) had the greatest supination torque and a smaller discomfort rating than the screwdriver with the pistol-grip handle. Blade length was not significantly related to any dependent measure."

"For safe job design, it is necessary to know the maximum acceptable work time (MAWT) for a given workload. The aim was to establish the relationship between MAWT and physical workload. Cycling tests at six different work rates relative to personal maximum working capacity were performed by 12 young adults in the laboratory. The oxygen uptake (VO2) in the per cent maximum aerobic capacity (%VO2max), relative heart rate (RHR) and relative oxygen uptake (RVO2) were collected throughout the test. MAWT was determined by observing the heart rate data during the test. The results showed that MAWT was negatively correlated with %VO2max, RHR and RVO2 (p <0.01). Three exponential regression models were obtained and all their R2 >0.80. These models suggest that long-hour shifts (>10 h) should assign a lower work intensity than for an 8-h workday. It is also logical that the workload limit for a 4-h work shift could be set at about 10% VO2max higher than the suggested limit for an 8-h workday."