ISSN: 2329-9096
Masahiro Nishimura1, Hyuna Kim1, Takashi Hasegawa2, Yasushi Uchiyama1*
Background: From the perspective of dynamic postural control, the separation between the Center of Foot Pressure (COP) and the Center of Mass (COM) has been linked to COP-COM coordination. Therefore, investigating the role of COP-COM coordination during acceleration in gait initiation is important. This study investigated whether COP- COM coordination was involved in acceleration control during gait initiation in community-dwelling elderly people.
Methods: Young (n=11; age: 22.2 ± 1.4 years) and healthy elderly (n=23; age: 71.9 ± 4.3 years) subjects walked a 12 m gait 5 times at a self-selected speed. The gait velocity from the first to third step and COM were detected using 15 markers on the subject’ s body via a motion capture system. COP was traced by a 2.4 m foot pressure distribution sensor. ‘COP-COM separation’ was calculated from the starting motion to the third step in Anteroposterior (AP) and Mediolateral (ML) directions. Elderly subjects were divided into two groups using the Timed-Up-and-Go-Test (TUG) time to compare sensitivity differences in balance ability.
Results: ‘COP-COM separation’ in the AP direction of elderly subjects with low TUG performance was significantly lower than that of other groups (p<0.001). Gait velocities on the second and third steps showed significant differences among groups (p<0.001). ‘COP-COM separation’ was associated with walking speed from the first to third step, regardless of age (p<0.05).
Conclusion: These results suggest that COP-COM coordination of healthy elderly is sensitive in the AP direction and contributes to the acceleration phase until steady-state walking