Kinematic methods for quantifying loss of balance while negotiating a curved path on a slippery surface.
Wang-B; Bhattacharya-A; Bagchee-A; Wang-W; Succop-PA
J Test Eval 1997 Jan; 25(1):135-142
Variables associated with the loss of balance were examined. Ten industrial workers walked on either a dry or slippery T-shaped walkway equipped with a force platform. Reflective foam markers were attached to the subjects. A four camera system was used to record the subjects' movements and determine coordinate data. A kinematic approach to analysis was applied. Fall potential indices included center of gravity (COG) deviation distance, total utilized coefficient of friction (COF), turning radius and COF used by centrifugal forces, slide distance during slipping, and slide direction during slipping. During turning, the COG on the horizontal plane (COGH) deviated markedly from the supporting foot, with the deviation distance increasing as the supporting foot slid. During the single stance period on the right foot, the COGH fell out of the base of the supporting area (BOSA) on a slippery surface and usually fell within the BOSA on a dry surface. The potential loss of balance was markedly lower when turning on a dry surface than when turning on a slippery surface. The centrifugal force contributed approximately 80% to the total utilized COF. The total slide distance was virtually the same for subjects walking either a curved or straight path, under the dry conditions. However, for the slippery conditions, the total slide distance measured 0.126+/-0.040 meters (m) on the straight path and 0.281+/-0.056m on the curved path. The average COG deviation distance was greater for subjects on a curved path than for those on a straight path. The mean slide direction was 52.7+/-5.1 degrees on a curved path and 60.8+/-5.2 degrees on a straight path. The authors conclude that turning on a dry or slippery surface is more difficult than walking in a straight direction on a dry or slippery surface.
NIOSH-Grant; Traumatic-injuries; Humans; Ergonomics; Walking-surfaces; Safety-research;
Environmental Health University of Cincinnati 3223 Eden Ave Cincinnati, OH 45267-0056
Journal of Testing and Evaluation
University of Cincinnati, College of Medicine, Cincinnati, Ohio