Postural adaptation at elevated and sloped surfaces.
Simeonov-P; Hsiao-H; Ammons-D
NOIRS 2003-Abstracts of the National Occupational Injury Research Symposium 2003, October 28-30, Pittsburgh, Pennsylvania. Pittsburgh, PA: National Institute for Occupational Safety and Health, 2003 Oct; :84
Falls from roofs continue to be a major cause of death and disabling injury in construction. The elevated and sloped roof surfaces seriously challenge postural control and increase the risk of loosing balance. Understanding how workers adapt to the extreme roof environments and identifying the limits for successful balance control will allow development of recommendations for safe work practices, and new fall-prevention techniques. Twenty-four construction workers performed three consecutive standing trials on sloped surfaces (0 , 18 , 26 , 34) at height (3m) and on the ground with close references included or excluded from their visual field. Standing balance was determined from the center-of-pressure movement recorded from a force platform. Dependent variables included sway velocity and mean power of anterior-posterior sway in twelve 0.25-Hz-wide frequency-bands in the range 0-3Hz. Trial effects and factor interactions were used to make inference about the adaptive patterns in workers' balance control. The results indicate that balance control at elevated and sloped surfaces, involves an initial period of postural adaptation, characterized by a burst of 0.5-1.5-Hz-sway power (up to 5 times the baseline values) during the first standing trial. Balance control at steeper slopes required higher sway frequency for longer time periods. At slope 34 , task repetition lead to progressive increase in 1.00-1.25-Hz-sway variability, indicating a tendency of postural degradation. Task repetition without close visual references caused increased mean values and variability in 1.25-1.50-Hz sway, while with visual references it resulted in progressive decrease of these parameters. Overall, the study results imply that workers in roof construction are at an increased risk of losing balance immediately after stepping on a sloped roof. Visual references can considerably improve postural adaptation on sloped roofs. Roof surfaces with 34 (8/12) slope are at the limits for postural adaptation, and thus increase the risk of falling.
Posture; Construction-industry; Construction-workers; Occupational-accidents; Occupational-hazards; Roofing-industry; Roofers; Injuries; Traumatic-injuries; Injury-prevention; Risk-factors
Abstract; Conference/Symposia Proceedings
NOIRS 2003-Abstracts of the National Occupational Injury Research Symposium 2003, October 28-30, Pittsburgh, Pennsylvania