Technical Details
- Variable Type: Movement Flag
- Data Type: Integer
- Units: N/A
- Column Name:
contact_phase_open_trunk_rotation - Optimal Direction: Lower is better
- Unknown Value: -1
- Measurement: Trunk rotation (transverse plane) relative to the serve direction at Apex
- Threshold: Trunk rotation greater than -20°
Description
Contact phase open trunk rotation is a binary indicator that flags when the trunk has rotated too far in the serve direction (past -20°) at the time of ball contact. This indicates the torso is “opening up” too early relative to the arm and ball.Use Cases
- Rotational sequencing assessment
- Mechanics evaluation