Due to the nature of Wing Chun techniques tremendous upper body flexibility is required. This flexibility takes place at the wrist, shoulder, shoulder girdle and radio-ulnar joint. Techniques leave little room for mechanical compensation and for this reason, even small amount of tightness in any of the muscle can lead to injury. Rotator cuff injury are the most common.
Another common injury is muscle overstrain. This usually happens because the body is forced to stay in positions, that is not properly stretched for. Severe internal and external rotation of the shoulder, as well as severe horizontal flexion/abduction are some of those positions.