Learning Objectives:

1. Understand the validity and measurement accuracy of the OpenCap markerless motion capture system for assessing lower-extremity kinematics during the multi-planar Star Excursion Balance Test (SEBT). 2. Identify how OpenCap's performance differs across sagittal, frontal, and transverse planes, and recognize the system's limitations in detecting subtle rotational movements. 3. Evaluate the applicability of OpenCap in both normal and simulated abnormal movement conditions, and interpret its potential role in clinical decision-making, injury screening, and return-to-sport assessments.

Keywords: Cloud-based motion capture; Open-source motion capture technology; SEBT