Christiansen MB, Thoma LM, Master H, et al. - This research was sought to evaluate the feasibility, fidelity, safety, and preliminary outcomes of a physical therapist–administered physical activity (PA) intervention after total knee replacement (TKR). Researchers randomized people who underwent a unilateral TKR and were receiving outpatient physical therapy (PT) to a control or intervention group. They assessed feasibility by rates of recruitment and retention, safety was assessed by the frequency of adverse events, and fidelity was evaluated by adherence to the weekly steps/day goal created by the physical therapist and participant monitoring of steps/day. A physical therapist–administered PA intervention was found to be beneficial and safe, indicate treatment fidelity, and may elevate PA after TKR. Further study is required to develop the efficacy of the intervention.