Anterior cruciate ligament (ACL) tears are one of the most debilitating sport injuries sustained by recreational and elite athletes. An estimated 250,00 ACL ruptures occur in the US each year and nearly half of those are repaired by surgical reconstruction. Conventional wisdom suggests that nearly all athletes fully return to play after ACL reconstructive surgery. However, recent data suggests that of NFL players who experience an ACL tear, over 20% never return to play, and those who do return perform at only 1/3 of pre-surgery levels. Consequences of some ACL reconstructive procedures, as well as pre- and post-operative mechanical unloading, lead to neuromuscular function and bone and muscle mass losses. In addition, new data shows that bone loss occurs and remains low even several years after surgery, which may contribute to increased risk of osteoarthritis in later life.