Can OpenCap deliver valid and reliable kinematic data for motion analysis? A systematic review and three-level meta-analysis
Biology of Sport, cilt.43, sa.1, ss.555-573, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Derleme
- Cilt numarası: 43 Sayı: 1
- Basım Tarihi: 2026
- Doi Numarası: 10.5114/biolsport.2026.154942
- Dergi Adı: Biology of Sport
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, CINAHL, Directory of Open Access Journals
- Sayfa Sayıları: ss.555-573
- Anahtar Kelimeler: Markerless motion capture systems, OpenCap, Reliability, Three-level meta-analysis, Validity
- Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
- Ankara Yıldırım Beyazıt Üniversitesi Adresli: Evet
Özet
Markerless motion capture systems have gained increasing interest as practical alternatives to gold-standard references systems in clinical and sports contexts. This systematic review and three-level meta-analysis aimed to evaluate the criterion validity of OpenCap and to systematically summarize the available evidence regarding its reliability. A literature search was conducted across Web of Science, PubMed, Scopus, and EBSCO. Among the 12 studies included in the systematic review, 11 provided sufficient data for the meta-analytic synthesis of criterion validity, encompassing 184 participants, from which 640 effect sizes (ES), 230 Fisher’s Z values, and 1087 root mean square error (RMSE) values were obtained. OpenCap demonstrated a statistically significant, yet practically trivial effect compared to criterion devices (ES =-0.140; p = 0.021). Fisher’s Z transformation indicated a good-to-excellent correlation with criterion devices (r = 0.845; p = 0.005). The pooled RMSE was 5.877°, which decreased to 5.197° after sensitivity analysis and further to 4.940° following trim-and-fill adjustment. In terms of reliability, test-retest consistency generally ranged from moderate to very good across many joint angles and tasks, although marked variability was observed in certain task-joint combinations, particularly in high-velocity movements and complex joint actions. OpenCap, as a smartphone-based markerless motion capture system, can provide valid and acceptable kinematic measurements when compared to criterion devices. However, its performance varies depending on task complexity and joint-specific demands, underscoring the need for evaluation across diverse populations, a wider range of task types, and within standardized methodological frameworks.