Using smartphone video to measure knee movement in osteoarthritis
Using Mobile Technology to Extract Mechanical Markers of Joint Health and Function in Early Knee Osteoarthritis
This project will test whether a smartphone video system called OpenCap can measure knee movement and mechanics in people with early knee osteoarthritis and how those measurements compare with lab motion capture, symptoms, and knee imaging.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 47 (estimated) |
| Ages | 30 Years and up |
| Sex | All |
| Sponsor | VA Office of Research and Development Federal |
| Locations | 1 site (Palo Alto, California) |
| Trial ID | NCT07580222 on ClinicalTrials.gov |
What this trial studies
This observational study enrolls adults with early knee osteoarthritis to collect smartphone video using OpenCap during functional activities and compare the derived joint mechanics to conventional marker-based motion capture, patient-reported symptoms, and knee joint structure. OpenCap uses at least two smartphones plus machine learning and musculoskeletal modeling to estimate movement mechanics without specialized lab equipment. The study will recruit participants (veteran and non‑veteran) who previously qualified for a specified PRP study and meet standard health and BMI eligibility criteria, and will perform concurrent measurements at the VA Palo Alto site. Results will characterize OpenCap's validity in a knee OA population and inform whether the tool could be used or refined to help detect mechanical markers earlier in the disease course.
Who should consider this trial
Good fit: Adults (veteran or non‑veteran) with diagnosed early knee osteoarthritis who previously participated in the specified PRP study, can provide informed consent and perform the required functional activities, have BMI ≤35 kg/m², are not pregnant, and do not have other symptomatic lower‑limb OA, joint replacement, or rheumatic disease.
Not a fit: Patients with advanced knee OA (including joint replacement), symptomatic lower‑body OA elsewhere, rheumatic disease, BMI >35 kg/m², severe systemic disease (ASA ≥3), or who are pregnant are unlikely to benefit from this study's findings.
Why it matters
Potential benefit: If successful, this approach could enable low-cost, widely accessible measurement of knee mechanics to help detect and track osteoarthritis earlier and expand monitoring beyond specialized labs.
How similar studies have performed: Markerless and smartphone-based motion capture methods have shown promising accuracy in biomechanics research, but OpenCap specifically has not yet been validated in patients with knee osteoarthritis.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Veteran and non-Veterans * males and females * diagnosed with early knee osteoarthritis * qualified for and participated in the Precision Assessment of Platelet Rich Plasma for Joint Preservation study (ClinicalTrials.gov ID: NCT03460236) * able and willing to provide informed consent for follow-up study Exclusion Criteria: * symptomatic OA in joints other than the knee in the lower body * joint replacement * rheumatic disease * BMI \> 35 kg/m\^2 * severe systematic disease defined as American Society of Anesthesiologists (ASA) 3 or above * pregnant or intending to become pregnant during the study
Where this trial is running
Palo Alto, California
- VA Palo Alto Health Care System, Palo Alto, CA — Palo Alto, California, United States (Recruiting)
Study contacts
- Principal investigator: Jade He, PhD — VA Palo Alto Health Care System, Palo Alto, CA
- Study coordinator: Jade He, PhD
- Email: Jade.He@va.gov
- Phone: (650) 493-5000
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.