INTRODUCTION
Knee osteoarthritis (OA) is a common age-related clinical condition that has a major impact on function and independence (1), including limitations in walking, stair climbing, rising from a seated or prone position and household chores (2-5). Total knee arthroplasty (TKA) is a highly and increasingly prevalent surgery (6) recommended to those with knee OA showing radiographic evidence of joint damage, moderate to severe persistent pain and clinically significant functional limitations that diminish quality of life (7). Although TKA results in reduced pain and improved perceived function (8), patients continue to exhibit reduced voluntary muscle activation, muscle strength and functional performance even years after surgery (8). Quadriceps muscle strength deficits following TKA have considerable long-term consequences associated with impairments in functional activities (i.e., walking and stair climbing) and lower-limb loading distribution (8,9), as well as the progression of OA in the uninvolved leg (9,10).