Preventing Posttraumatic Osteoarthritis With Physical Activity Promotion

"After enrolling, participants will be outfitted with a Fitbit Charge 2 activity monitor. The monitor will be worn during all waking hours, and compliance will be considered as a day with ≥ 1,000 steps. Participants will complete a 14-day run-in observation period while wearing the Fitbit but no PA promotion will occur. Individuals who are noncompliant during the run in period (\<10 days with \<1,000 steps) will be removed. Participants will receive a text message each morning with a personalized, daily step count goal and a link used to confirm receipt of the goal. The preceding 10 days of step data will be rank ordered and the 60th percentile step count will be set as the goal for the next day."