2025 Volume 3 Issue 1 Pages 106-113
Objective: The purpose of this study was to determine the validity of trunk rotation assessment during baseball pitching using OpenCap, a pose estimation–based motion analysis application.
Methods: We analyzed the pitching motion of 13 healthy men with baseball experience using optical 3D optical motion analysis (3D–Mocap) and OpenCap. We assessed pelvic and trunk rotation during the pitching motion and compared the two methods.
Results: Pelvic rotation angle, trunk rotation angle, difference between pelvic and trunk rotation angles at stride foot contact, maximum pelvic rotation velocity and maximum trunk rotation velocity were significantly correlated between 3D-Mocap and OpenCap (ρ＝0.599‒0.879, p＝0.001‒0.031). Fixed errors of 9° for trunk rotation, −12° for the difference between the pelvic and trunk rotation angles, 147.9°/s for the maximum pelvic rotation velocity and 215.2°/s for the maximum trunk rotation velocity were detected.
Conclusion: Although some differences in angle measurement between 3D-Mocap and OpenCap should be acknowledged, OpenCap is a clinically friendly tool and would be useful for the clinical assessment of trunk and pelvic rotation during baseball pitching.
