A Novel Physical Therapy Administered Physical Activity Intervention After TKR: A Pilot Study

The purpose of this study is to: 1. Determine whether the Physical Therapy (PT) \& Fitbit® intervention should proceed to a full-scale clinical trial. This decision will be based on three hypotheses: Treatment promise (Hypothesis 1A): People in the PT \& Fitbit® will walk 1250 more steps/day and spend 7 min/day more in moderate to vigorous physical activity (MVPA) than the control at discharge and at 6 months and 12 months, Safety (Hypothesis 1B): \< 5% will have adverse events because of the intervention, A research assistant will collect data on adverse events that occur from the time of randomization until the last follow-up visit 3 months after discharge from PT. An adverse event is any unfavorable or unintended diagnosis, sign, symptom, or disease temporarily associated with the study intervention, which may or may not be related to the intervention. Adverse events include any new events not present during the pre-intervention period or events that were present during the pre-intervention period which have increased in severity. Major adverse events, such as infection, re-hospitalization or development of new comorbidities will also be noted. Recruitment (Hypothesis 1C): 75 recruited, 90% to complete trial, and 85% complete visit at 6 months and 12 months. 2. To evaluate the short- and long-term adherence of the PT \& Fitbit® intervention. Short-term Adherence (Hypothesis 2A): 90% of subjects in the PT\& Fitbit® group will wear the Fitbit® and participate in goal setting and behavioral counseling while in PT. Long-term Adherence (Hypothesis 2B): 75% of PT \& Fitbit® will wear the Fitbit® at 6 months and 12 months. 3. To quantify changes in potential underlying mechanisms for increased physical activity. (Hypothesis 3): Change in self-efficacy for physical activity, walking endurance and participation in daily activities will be associated with improvements in physical activity. 4. To assess intervention fidelity (Hypothesis 4): (4a) using the electronic medica