Osteoarthritis is the leading cause of disability in the U.S, particularly in older adults. Exercise is an evidence-based treatment option that improves pain and disability outcomes in adults with osteoarthritis, but adherence to prescribed exercise is generally low. Technology such as mobile applications (apps) for smartphones and tablets offers the potential to support exercise adherence through evidence-based components and enhanced communication between physical therapists and patients. The investigators aim to test mobile app-supported physical therapy exercise prescription compared to standard care. The investigators propose to use a two-arm randomized control trial with subjects in the intervention receiving mobile app-supported physical therapy exercise prescription and the control group receiving usual care physical therapy exercise prescription (paper handouts and verbal instruction). No known studies have assessed the impact of technological integration on adherence with PT exercises for OA. Current approaches such as therapist drawn pictures, hand-written or print-ready instructions do not account for patient communication preferences or ability to translate drawings into physical action. Mobile technology offers a potential solution to patient-centered care but has not been evaluated. This study will provide valuable information on effectiveness and user perspectives to key stakeholders such as patients, health care administrators, physical therapists and app designers.

Osteoarthritis (OA) is the leading cause of disability in the U.S. The rate of activity limitation due to OA is progressing faster than expected while prevalence is projected to increase as a result of the obesity epidemic and population aging, making it a major public health problem. Exercise is an evidence-based treatment option that improves pain and disability outcomes in adults with osteoarthritis, but previous research has shown that adherence to prescribed exercise is low. Referral to physical therapy is common for people with OA with the standard of care including exercise prescription through paper handouts with brief instruction and static pictures. Such approaches do not incorporate known determinants of behavior change related to exercise adherence.

Recent technology products such as mobile applications (apps) for phones and tablets offer the potential to enhance communication between physical therapists and patients. The investigators aim to test a pragmatic intervention focused on supporting people with osteoarthritis to remain engaged with an exercise program. The specific aims of the project are to:

1. Compare the effectiveness of mobile app supported exercise prescription to usual care (paper exercise prescription) on exercise adherence among mid-life and older adults receiving similarly dosed physical therapy for lower extremity OA. The investigators will also examine secondary outcomes of exercise self-efficacy, physical function, stiffness, and pain.
2. Examine the feasibility and acceptability of mobile app supported exercise prescription through recruitment and retention rates, satisfaction with care ratings, and qualitative feedback.

Inclusion Criteria:

1. Self-report of healthcare provider diagnosed osteoarthritis in the hips or knees
2. Ability to speak and read English
3. No diagnosis of serious mental illness
4. No diagnosis of serious or terminal illness (e.g., metastatic cancer, end stage renal failure)
5. Access to smartphone/tablet

Exclusion Criteria:

1. Cortisone injection to the joint with OA within the past 30 days
2. Undergoing physical therapy post-total joint replacement or in preparation for total joint replacement in the next 3 months
3. History of physical therapy for treatment of osteoarthritis in the past 6 months.