Hip Function Characterization in the Sagittal Plane with Varying Gait Speed by

The function of the human hip joint during the stance phase of walking can be characterized with a configuration of simple mechanical elements. This combination of elements is capable of providing general hip behavior in the sagittal plane. Data was collected from two healthy, young subjects who walked at slow, normal and fast gait speeds. The hip can be modeled with a torque actuator and two independent, linear torsional springs, which are activated at different times during the stance phase of gait. The activation times consistently identify gait cycle events across all three gait speeds. The first spring operates during the single limb stance of the gait cycle. The second spring is actuated during second double support, in the pre-swing phase. The springs effectively reduce the amount of work an unaccompanied torque actuator would have to exert in order to reproduce the hip gait pattern. Thesis Supervisor: Hugh M. Herr Title: Instructor, Harvard-MIT Division of Health Sciences and Technology