Lower extremity joint torque during a change in direction while walking

Abstract

To provide more effective instructions for walking exercise in physical therapy, this study investigated lower extremity joint torque during a change in direction while walking. The subjects were 9 healthy males who performed walking and direction changes by side stepping (SS) and crossover stepping (CS). SS was performed in a new direction by planting the right foot in the opposite direction. CS was performed in a new direction by planting the right foot on the same side and then crossing the left leg in front of the right leg. These movements were recorded using 4 infrared cameras. During each movement, the ground reaction force of the right lower extremity was measured using a force platform. Right lower extremity joint torque was computed using the results of a three-dimensional motion analysis system for these movements and the ground reaction force data. The results indicate that hip extension and external and internal rotation torques during CS were significantly greater than those during walking and SS. Hip abduction torque during CS was significantly greater than that during SS. In addition, knee flexion torque during CS was significantly greater than that during walking. In conclusion, the kinetic properties during CS are very different from those during walking and SS according to the joint torque data. Thus, it is important to consider the functions of hip extension and external and internal rotators in order to perform CS smoothly.