Postural stability effects in low seam mining tasks.
Gordon-J; Sobeih-T; Bhattachara-A; Succop--P
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 2004 May; :3
Performing work in underground low-seam mines requires working on slippery surfaces under poor lighting conditions with restricted postures that may cause a potential loss of stability/balance, especially during material handling tasks. The purpose of this study was to determine the effect of work surface properties, task type, and environmental lighting conditions on 25 miners’ ability to maintain "safe" upright balance while restricted to a 44-inch ceiling. Postural stability was quantified using a large force platform while performing simulated static tasks with different surface (dry, uneven, and slippery) and environmental lighting (poor and glare) conditions. During the testing workers performed the tasks in both a one-knee and two-knee posture. Parameters for characterizing postural stability included sway area (SA), sway length (SL), anterior/posterior (AP), and medial/lateral (ML) excursion. An increase in any of these parameters indicates an increase in postural instability. Postural instability was further evaluated using Index of Proximity to Stability Boundary (IPSB); a decrease in IPSB implies poorer balance/postural stability. Subjective ratings of perceived sense of sway (PSOS) and exertion (PE) during task performance was recorded. The tasks performed significantly increased the SA, SL, AP, and ML excursions (varying between 328% and 13,681%). The one-knee posture significantly increased the SA by 9% and the two-knee posture significantly increased the AP and ML excursions by 15% and 6%, respectively. Glare lighting conditions significantly increased the SL (by 4%). IPSB values were statistically significantly decreased (varying between 71% and 124%) for posture and task variables. The subjects’ PSOS and PE were statistically significantly different for all variables of task, posture, surface, and lighting. Results from this study indicate that performing these simulated tasks may result in postural instability, especially when working on slippery surfaces and/or in glare light conditions.
Posture; Mining-industry; Ergonomics; Underground-mining; Risk-factors; Neuromuscular-system; Neuromuscular-system-disorders; Injuries
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia
University of Cincinnati, Cincinnati, Ohio