Non‑contact Video Marker Tracking Quantification Platform

Research Hypothesis
Manual acupuncture twirling-rotating manipulation relies on precise thumb-index finger coordination that has remained insufficiently quantified due to lack of scalable, high-resolution measurement tools. We hypothesized that: (1) a low-cost video-based marker tracking platform could resolve fine-scale spatiotemporal kinematics of finger joints during needle manipulation; (2) nonlinear dynamic analyses would identify specific joints governing rhythmic stability and amplitude control; and (3) multi-modal coupling analyses would reveal modular, directionally asymmetric coordination patterns between thumb and index finger modules. Furthermore, we hypothesized that individual operators exhibit distinct motor fingerprints reflecting preferred thumb-dominant versus index-dominant strategies, detectable only with sufficient measurement sensitivity and temporal stability.
Data Collection
Hand kinematics were captured at 4K resolution (3840 × 2160 pixels) and 60 frames s⁻¹ using a stabilized optical setup oriented perpendicular to the thumb-index manipulation plane. Eight high-contrast black markers (3M™, model 55230) were positioned on predefined anatomical landmarks: ID1 (distal index finger), ID2 (distal interphalangeal joint of index finger), ID3 (proximal interphalangeal joint of index finger), ID4 (metacarpophalangeal joint of index finger), ID5 (distal thumb), ID6 (interphalangeal joint of thumb), ID7 (metacarpophalangeal joint of thumb), and ID8 (midpoint between first and second metacarpals). A stationary reference marker enabled spatial normalization and drift correction.