Relationship among gait parameters while walking with varying loads.

This study aimed to clarify the relationships between loads and gait changes and among gait parameters while walking with various loads. Fifteen healthy young male adults (mean age: 22.1+/-1.6 years) walked with four kinds of loads based on each subject's body mass (0, 20, 40, and 60% of body mass: BM) on his back. Walking speed, cadence, stance time, swing time, double support time, step length, step width, walking angle, and toe angle were selected as gait parameters.Walking speed, cadence, stance time, and double support time changed significantly with loads. The walking speed showed significant correlations with the swing time at 0% BM (r=-0.64) and the walking angle at 60% BM (r=-0.52). Significant correlations were found between swing time and double support time at 0, 20, and 40% BM (r=0.53-0.63) and between walking speed and step length at 40 and 60% BM (r=-0.61, -0.67). In conclusion, walking with loads produces large gait changes. The relationship between swing time, double support time, and walking speed, as well as between walking angle, step length, and walking speed changes greatly with loads. These changes may occur in order to maintain a stable posture.