Introduction: Femoral and acetabular replacement is characterized as total hip arthroplasty (THA). It has been used as treatment of various pathologies of this joint. In the postoperative period, some studies have shown that strength, function, range of motion and lower limb mechanics remains altered for more than One year after THA in relation to the non-operated side. However, studies that have correlated kinematics and hip muscle strength in individuals who underwent THA for long time, do not exist in literature. Objective: to evaluate lower limb muscle strength and 2D kinematics during stair ascending and descending in patients undergoing total hip arthroplasty. Methods: Third individuals who underwent total hip arthroplasty (THA) will be recruited at two, five and 10 year postoperative periods. They were allocated in three groups: Group 1 (10n), subjects submitted to THA for two years, Group 2 (10n) subjects submitted to THA for five years, Group 3 (10n) subjects submitted to THA for 10 years and Group 4 (10n) subjects without orthopaedic afections, all will be evaluated for dynamometric isometric muscle strength and kinematic analysis of stair ascending and descending by a "blinded" physical Therapist.

Inclusion Criteria:

• The investigators will recruit 40 individuals who underwent total hip arthroplasty (THA) by the hospital hip surgery group in the periods of two, five and 10 years postoperatively
• Control group without orthopaedic afections. Inclusion criteria: patients submitted to total hip arthroplasty between two years (24 months - 35 months), five years (60 months - 71 months) and 10 years (120 months - 131 months), aged between 50 and 80 years and sign the terms of free and informed consent

Exclusion Criteria:

• patients with a history of prosthesis dislocations or revision of arthroplasty
• hip or lower limb pain
• asymmetry of the lower limbs greater than two centimeters
• previous surgeries in the lower limbs
• limited range of motion in the hip joint
• use of antidepressive drugs or analgesics for continuous use
• Presence of neuromuscular pathologies and functional incapacity to perform the activities proposed in the Kinematics analysis.

40 individuals who underwent total hip arthroplasty (THA) by the hospital hip surgery group