Abstract. Objectives. Although hip replacement and resurfacing procedures both aim to restore mobility, improve joint function, and relieve pain, it is unclear how each differ in terms of gait mechanics and if they are affected by varying walking speeds. We compared limb symmetry and ground reaction force (GRF) profiles between bilateral total hip arthroplasty patients (THA), bilateral hip resurfacing arthroplasty patients (HRA), and healthy control participants (CON) during level-treadmill walking at different speeds. Methods.