The aim of the proposed trial is to evaluate the effectiveness of a progressive resistance rehabilitation program (PROG) after TKA compared to a traditional rehabilitation program (TRAD). The PROG intervention will involve intensive rehabilitation using progressive resistance exercise and faster progression to functional strengthening exercises. The TRAD intervention represents the synthesis of previously published TKA rehabilitation programs. Our preliminary data suggest that the PROG intervention has low risk and results in improved functional mobility and muscle strength. The investigators will measure function and strength at six time points (pre-op; 1, 2, 3, 6, and 12 months after TKA). The investigators will also evaluate the contribution of changes in muscle mass (atrophy/hypertrophy) and central activation to changes in muscle strength following PROG and TRAD interventions.