The biomechanics SCAPULOHUMERAL RHYTHM TRUTH RATIO: 2:1 humeroscapular ratio Setiap 30° humerus elevation = 10° scapula upward rotation Full 180° arms overhead = ~60° scapula upward rotation UPPER TRAP ROLE: Normal upper trap activation = REQUIRED untuk overhead Excessive upper trap = problem (chronic tension pattern) Beda antara "aktivasi normal" vs "over-activation" CONSEQUENCES OF FORCING SHOULDER DOWN: Restricts scapular rotation Creates humeral head impinge

The biomechanics WHY THESE 3 ASSISTS ARE DANGEROUS 1. DOWN DOG · Push Chest to Floor: Cue "chest open" sound legit tapi biomechanically compress bahu Rotator cuff impingement di sub-acromial space Repeat = tendon damage over time 2. LOW LUNGE · Press Hip Forward: Kalau hip flexor tight · pressed forward hit end range aggressively SI joint stress + potential injury Femoral acetabular impingement risk 3. COBRA · Pull Shoulder Back: Bukan bahu yang harus mundur · s