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Role of Center of Mass Kinematics in Predicting Peak Utilized Coefficient of Friction During Walking

NCJ Number
221670
Journal
Journal of Forensic Sciences Volume: 52 Issue: 6 Dated: November 2007 Pages: 1328-1333
Author(s)
Judith M. Burnfield Ph.D.; Christopher M. Powers Ph.D.
Date Published
November 2007
Length
6 pages
Annotation
Given the importance of understanding used coefficient of friction (COFu) in the context of pedestrian/walkway accidents (individuals who show a higher COFu are at greater risk of slipping), this study determined whether whole body center of mass (CM) kinematics were predictive of peak COFu during walking.
Abstract
Both CM-CP (center of pressure) angles of inclination and CM velocity in the anterior posterior direction predicted peak COFu during weight acceptance. The identified relationships between CM kinematics and peak COFu provide insight into how a person's gait and individual physical characteristics increase his/her risk for slipping while walking. Individuals with shorter legs whose length of stride is similar to that of individuals with longer legs could conceivably have increased CM-CP angles due to the lowered height of the CM. In addition, significant trunk leans that alter the CM location relative to the CP may also contribute to differences in peak COFu across individuals; however, only 62 percent of the variance in peak COFu could be explained by the model, which suggests that further investigation is required in order to identify factors that influence COFu values. Study participants were 49 individuals (28 males, weight range of 67-116 kg; 21 females, weight range 52-135 kg) between the ages of 22 and 40. Ground reaction forces and kinematic data were recorded simultaneously as subjects walked on a 10-meter walkway. The middle 6 meters were designated for data collection. Light-sensitive triggers were used to initiate and terminate data collection as subjects progressed along the walkway. Three-dimensional motion analysis was performed with a six-camera system. Reflective markers placed over specific anatomical locations were used to calculate the CM location. 3 tables, 5 figures, and 28 references