Numerical Calculation of Hip Squeak Over the Normal Gait Cycle

Abstract

This paper present the numerical and analytical hip squeak model using the normal gait data acquired from the experiment. The axis of the ground reaction force is defined on the hip joint at the successive position of the right hip during the gait cycle. The contact pressure and its distribution on the ball are calculated by the Hertz theory at the corresponding cycle. The eigenvalue sensitivity analysis is conducted at the quasi-static state of the successive position of the right hip for both the full lubrication and the mixed lubrication. For the full lubrication case, the hip joint system becomes dynamically unstable only when the hip extends. In the mixed lubrication, the 2nd bending mode has the very high squeak propensity and its frequency drastically varies with the gait cycle.