Influence of Wearable Activity Monitors and Social Support on Physical Activity After Knee Replacement

Patients undergoing knee replacement typically report improved health-related quality of life, increased physical function, and reduced pain. Despite these improvements, physical activity levels remain unchanged, or only minimally increase from pre-operative levels, yet do not reach the same level of activity observed among healthy populations. Knee replacement patients often expect their activity levels and function to improve following surgery, but the majority of patients' activity levels 5 years post-operatively did not meet their pre-operative expectations. Even though improvements are observed in pain and function, reasons for the maintenance of low levels of activity are unknown. Technology has the potential to increase physical activity levels in these patients, particularly as 81% of knee replacement patients in our recent study had a smartphone, and 40% were willing to wear a wrist-worn physical activity monitor. As the average age of knee replacement continues to decrease, we anticipate that the percent of patients with a smartphone and willingness to wear an activity monitor will increase. In addition to technology, social support is associated with greater outcomes following knee replacement. Thus, wearing a wrist-worn physical activity monitor and providing additional opportunities for social support via the technology may increase physical activity levels in these patients. The current pilot study aims to gain preliminary data on the influence of wearables and social support on physical activity in knee replacement patients following surgery. Specifically, we aim to recruit 20 patients who will be randomized to one of two conditions: Fitbit vs. Fitbit+Support. Participants in the Fitbit group will receive a Fitbit and be encouraged to wear it for 4 months. Participants in the Fitbit+Support group will be asked to identify a "buddy." Both the participant and "buddy" will be given a Fitbit and they will be asked to friend each other via Fitbit and wear the monitor for 4 months.