Total Knee Arthroplasty (TKA) is actually the most effective treatment option for patients with end-stage osteoarthritis (OA). However, nearly 20% of patients who underwent TKA remain unsatisfied with their clinical outcome. Investigating modifiable factors that limit knee functioning following TKA we may notice the significance of lower limb muscles strength. Gait pattern is also affected by OA, as arthritic knee joint cannot provide proper range of motion (ROM) and stability.Therefore any deviation in biomechanics should be noticed and analyzed. After TKA patients' physical function may change, but the study should be conducted to prove whether it improves or not. Patient-reported outcome defined by OKS (Oxford Knee Score) and FJS (Forgotten Joint Score) questionnaires will be evaluated.