This research will analyze and compare the muscle activation levels, muscle recruitment timing, trunk kinematics, and shoulder joint kinematics between the four forehand strokes and between elite table tennis players with and without shoulder injuries, providing insights for daily training and rehabilitation programs to reduce the occurrence of sports injuries.

The study participants will be elite table tennis players aged between 13 and 40. Participants must have competed in the Chinese Taipei Table Tennis Ranking Tournament or the National Table Tennis Championships within the past three years and have at least four years of table tennis experience, and train for more than 10 hours per week.

The study involves four types of forehand strokes: forehand topspin against topspin, forehand topspin against backspin, forehand stroke, and forehand attack.

Inclusion Criteria:

• The ages range from 13 to 40 years old
• Competed in the Chinese Taipei Table Tennis Ranking Tournament or the National Table Tennis Championships within the past three years
• At least four years of table tennis experience, and train for more than 10 hours per week

Exclusion Criteria:

• History of upper limb surgery or fracture
• History of shoulder dislocation
• History of spine injury in the last year
• Systemic autoimmune disease or cancer
• Pregnancy
• Any neurological complications

Table tennis players