GENDER DIFFERENCES IN EXPOSURE TO PHYSICAL RISK FACTOR S DURING STANDARDIZED COMPUTER TASKS

摘要

OBJECTIVES: The aim of this study was to determine whether there were differences in exposure to physical risk factors between genders in a series of standardized laboratory- based tasks on computer workstations adjusted to wubject anthropometry. METHODS: Thirty computer users (15 men and 15 women) completed five different tasks. Surface electromyography measured muscular activity in the shoulders (anterior deltoid, medial deltoid, and trapezius) and wrists (extensor carpi radialis, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris). Electrogoniometers and electromagnetic sensors measured posture of the wrists and shoulders, respectively. A force-sensing platform placed under the keyboard measured typing force. Whole body and upper extremity anthropometric measurements were recorded manually. RESULTS: Normalized muscle activity (EMG), the forces applied to the keyboard relative to the maximum force of the fingertip (%MVC), and range of motion were consistently higher for women. Shoulder posture was less neutral for women. Pearson correlations revealed strong associations between anthropometric variables (height, shoulder width, and arm length) and physical risk factors (EMG, range of motion, force) that are different between genders. CONCLUSIONS: Women have greater exposure to physical risk factors during identical tasks on a computer workstation. Exposure to these risk factors was strongly correlated to anthropometric differences between genders. This demonstrates how biomechanics plays a role and may contribute to the higher prevalence of upper extremity musculoskeletal disorders found in females.