Hip abductor muscle weakness after Total Hip Arthroplasty may lead to functional impairment, such as limping and reduced walking speed and also contribute to fall. The recovery period for the hip abductor muscles varies greatly and may last up to two years after surgery. So this textbook explains about the changes in hip abductor strength and endurance after one year in Total Hip Arthroplasty side in comparison with non-operated side. Rehabilitation of the muscles with exercises to strength the hip abductors as well as endurance training for prolonged period of time is mandatory. The studies of muscle strength and functional outcome following Total Hip Arthroplasty are more limited and the results are also varied.