This study examines the balance and movement of patients who have had a hip replacement surgery to find out whether one type of this surgery has better outcomes than other types. This study is currently recruiting subjects. Eligible subjects must be over the age of 18 and will have had a hip replacement without major complications six or more months ago performed at Carilion Clinic. Eligible subjects must not have ever had any other major leg injury and must not have had any leg extremity injury in the past two weeks. Testing will take place at the Carilion Institute for Orthopaedics and Neurosciences in Roanoke and will take approximately 30 minutes to complete. If you are interested in taking part in this study, please send an email to Lindsay.