The Effects of Contralateral Trunk Tilt on Elbow Varus Torque in Baseball Pitchers: A Critically Appraised Topic

Area of Science:

• Sports Medicine
• Biomechanics
• Orthopedic Surgery

Background:

• Ulnar collateral ligament (UCL) injuries are prevalent in baseball pitchers.
• Excessive elbow varus torque is a primary risk factor for UCL injuries.
• Trunk tilt (motion in the frontal plane) is a potential modifiable factor influencing medial elbow loading.

Purpose of the Study:

• To investigate the relationship between increased contralateral trunk tilt and elbow varus torque in baseball pitchers.
• To determine if trunk tilt influences medial elbow loading during the pitching motion.

Main Methods:

• A systematic review of four controlled or descriptive laboratory studies was conducted.
• Studies included high school, college, and professional baseball pitchers.
• Elbow varus torque and trunk tilt were measured or simulated across different pitching conditions.

Main Results:

• Three of the four included studies found a positive correlation between increased contralateral trunk tilt and increased elbow varus torque.
• Consistent findings across studies suggest a direct relationship between trunk tilt and medial elbow stress.

Conclusions:

• Moderate evidence indicates that greater contralateral trunk tilt is associated with higher elbow varus torque in baseball pitchers.
• Trunk tilt represents a potentially modifiable biomechanical factor for mitigating medial elbow stress and reducing UCL injury risk.