Digital Home-Based Physical Activity Promotion for Older Adults After Total Hip Arthroplasty

KOKU is a digital adaptation of the evidence based Otago Exercise Program and Falls Management Exercise program, both designed to improve strength, balance, and reduce fall risk in older adults. KOKU includes 26 balance and strength exercises of varying difficulty. Each exercise is accompanied by written and audio instructions for safe performance and is demonstrated by a virtual trainer. Training sessions consist of three exercises suggested by the KOKU app, which participants are encouraged to perform for as many repetitions as possible until fatigue. Progression is guided by the participant's subjective assessment of effort and difficulty. Participants may choose to perform any exercise at any time, regardless of the app-suggested sequence. The KOKU app also provides reminders to exercise if no activity is detected for two days.

Personal coaching consists of three video calls conducted via the study tablet by staff trained in BCTs and motivational communication skills. Participants receive a low cost, wrist worn activity tracker during the initial home visit to support self-monitoring and provide feedback on PA behavior. The first virtual coaching session (week 2) focuses on goal setting and action planning, the second session (week 3) addresses identification and management of barriers, and the third session (week 12) serves as a booster to review and adjust activity goals for the post intervention period.