To investigate the gait dynamics and hip muscle recruitment patterns associated with pre- and post-operative total hip replacement (THR), a gait analysis was performed on THR patients prior to surgery, and at four and eight months after surgery. Asymmetries between the afTected and contralateral limbs were significant for ground reaction forces and hip kinematics at al1 the points. Patients used less hip extension moment, not hip abduction moment, possibly to reduce hip compressive loads. Cane use decreased affected hip abduction moment and ground reaction forces, but had no significant effect on lateral torso sway or hip kinematics. Cane use may have increased the abduction moment in the good bip, potentidy accelerating disease. At four months post-operative, tensor fascia lata activity was Longer, potentially as compensation for a surgicly damaged gluteus medius. Results of this study provide quantitative data about the post-operative progress of THR patients with regard to gait dysfunction.