Simultaneous, bilateral, and three-dimensional gait analysis of elderly people without impairments

OBJECTIVE: The main objectives of this study were to determine if the right and left lower limbs in the gait of elderly people developed similar muscle moment and power patterns and to determine whether their associated mechanical energies were different during two consecutive gait cycles. DESIGN: A total of 18 able-bodied male subjects aged 71 +/- 6.8 yrs participated in this study. Data were collected using three Optotrak position sensors and two AMTI force platforms. RESULTS: The peak muscle powers were very similar in the sagittal plane and reflected gait symmetry, except for greater and significant differences produced by the hip extensors. Differences in the frontal and transverse planes were mainly attributed to the actions taken by the muscles, leading the lower limbs to compensate and to dynamically balance and propel the body forward during two consecutive gait cycles. In terms of mechanical energy, 13% greater positive work was done in the left limb and was associated with asymmetrical behavior of the lower limbs to propel the body forward. The total negative work was similar for both limbs, and substantial work was done in the frontal plane by the hip, indicating the role of muscle activity in this plane to control the pelvis and trunk against gravitational forces. CONCLUSIONS: In addition to the importance of a balance-control function in the gait of healthy, elderly subjects, muscle activity made an important contribution to propelling the body forward. Gait asymmetry in elderly subjects seems to be related to different degrees of energy generated by the lower limbs for the propulsion function, whereas both limbs contribute similarly to the balance-control function.