AN ANALYSIS OF THREE-DIMENSIONAL TRUNK, PELVIS AND LEG MOVEMENTS IN GAIT OF NORMAL SUBJECTS
Shu Watanabe, Kazushige Kobayashi, Satoshi Miyano, Kyozo Yonemoto, (Dept, of Rehab, Med, The Jikei Univ, school of Med, Tokyo, Japan)
Lennert Gransberg, Evert Knutsson (Dept, of Clinical Neurophysiology, Karolinska Hosp, Karolinska, Sweden)
Three-dimensional trunk, pelvis and leg movements during walking were studied quantitatively in 23 normal adults using an electromagnetic tracking instrument. In this system, angular displacements and vertical, lateral and sagittal displacements of the trunk, pelvis, thigh, lower leg and foot were able to be measured.
Angular displacement curves of the trunk and the pelvis have a consistent relationship to each other. In the transverse plane, the truncal rotation was synchronized with the pelvic rotation in the opposite direction. In the sagittal plane, the trunk and the pelvis rotate in the same direction throughout the whole gait cycle. In the coronal plane, the direction of rotations in trunk and pelvis was the same. In addition, the range of the trunk rotation in the transverse plane was not different from that of pelvic rotation indicating that in normal walking, same amplitude of the range of the trunk as the pelvis is necessary in the transverse plane. These findings suggest that trunk itself moves independently and is well coordinated with the pelvis, may be for the purpose of efficient locomotion. This is a preliminary report for ongoing investigations of the trunk, pelvis and leg movements in patients with various kinds of gait disturbances.
ENERGY EXCHANGE BETWEEN KINETIC ENERGY AND POTENTIAL ENERGY OF THE HUMAN BODY'S CENTER OF GRAVITY IN NORMAL GAIT
H. Kanzaki, H. Iida, I. Kawano, K. Mukai, S. Irie, C. Hayashi, T. Nakamura
(Kyoto University Hospital, Kyoto, Japan)
The purpose of this study is to evaluate the proportion of exchange between potential energy (PE) and kinetic energy (KE) of the center of gravity (COG) in normal gait. Kinetic analysis was made using force platforms in twelve normal subjects. Each subject was ordered to walk at a free velocity more than five times. Gait parameters were calculated including 1) time-distance factors , 2) three dimensional acceleration, velocity, displacement of COG, 3) PE, KE and total energy (TE) of COG, and 4) work done on the COG due to variations in potential (Wtp), kinetic (Wtk), and total energy (Wtt). The results are shown in the table.
"1 - Wtt/(Wtp+Wtk)" means the proportion of energy exchange between PE and KE to the sum of work necessary to change PE and KE of COG. The effects of sex and gait velocity on this parameter were not significant. This parameter was considered to be a good index for evaluating the mechanical efficiency of walking.