School of Biomedical Engineering, Konkuk University, Korea.

Speech Title: Upper body accelerations during locomotion in different age groups and genders
Abstract: Aim: The purpose of this study was to measure the acceleration of upper body (pelvis, shoulder, and head) during walking and to investigate whether the acceleration patterns differ among age groups and genders.
Methods: Twenty-nine old subjects and thirty young subjects participated in this study. Tri-axial accelerations were measured on the back of upper body (head, shoulder, and pelvis). Subjects performed two trials of walking on a treadmill in their own comfortable speeds. Three-way ANOVA (repeated measures) was carried out for the root-mean-square of each directional acceleration with age, gender and position as independent factors.
Results: ANOVA showed significant age differences on the RMS accelerations of transverse plane. In the anteroposterior direction, the pelvis acceleration was greater in the younger group, while the head acceleration was greater in the older group (p <0.05). In the mediolateral direction, the pelvis acceleration was comparable between age groups but the shoulder and head accelerations were greater in the older group (p <0.01). ANOVA also showed that the overall accelerations were greater in men than in women (p <0.01).
Discussion: Greater head acceleration in older subjects were resulted from smaller attenuation of acceleration in the upper body (trunk and neck), which would affect the performance of sensory systems in the head and may deteriorate balance control during locomotion.