VARIABILITY IN KINEMATIC MEASURES OF GAIT IN HEALTHY OLDER ADULTS

Abstract

Age-related changes in the kinematics of stepping in healthy older adults often alter performance. As falls are often the result of tripping over an obstacle, a better understanding of the kinematic measures associated with obstacle avoidance is needed. PURPOSE To examine within-subject variability in kinematic measures of obstacle avoidance in a group of healthy older adults. Avoidance measures included toe clearance, heel clearance, obstacle crossing speed, horizontal shear, and gait velocity. METHODS Thirty healthy older adult participants involved in a larger investigation examining the effects of an indirect dynamic multi-sensory training protocol were examined. Pre- and post-test measurements were obtained for toe clearance, heel clearance, obstacle crossing speed, horizontal shear, and gait velocity. RESULTS Descriptive statistical analysis revealed higher within-subject variability for measures of toe clearance (M 4.26 cm. +/− SD 2.63 cm), heel clearance (M 5.98 cm. +/− SD 2.80 cm.), and horizontal shear (M 109.41 N +/− SD 40.89 N) when compared to the variability for measures of obstacle crossing speed (M .428 m/sec.+/− SD .094 m/sec.) and gait velocity (M .892 m/sec. +/− SD .185 m/sec.). DISCUSSION Results suggest that there is significant variability in kinematic measures associated with obstacle avoidance in healthy older adults. Variability in obstacle avoidance strategies in older adults may account for increases in trips and stumbles and may make group generalizations about both performance and research difficult. These results indicate that further examinations designed to assess functional measures associated with stepping and gait need to account for these large variations in performance and previous research needs to be re-examined.