Contralateral Trunk Tilt in High School Baseball Pitchers: Comparison and Relationship with Trunk Rotational...

Area of Science:

• Biomechanics of baseball pitching
• Sports medicine research
• Injury prevention in adolescent athletes

Background:

• Excessive contralateral trunk tilt (CLT) during pitching increases shoulder and elbow torque.
• Core strength influences CLT, but the link between trunk rotation mobility and throwing injuries remains unclear.

Purpose of the Study:

• Compare trunk rotational mobility and compensatory lateral flexion in adolescent pitchers with high vs. low CLT.
• Examine associations between these trunk movements, player characteristics, ball velocity, and elbow valgus torque.

Main Methods:

• Cross-sectional study of 19 male adolescent pitchers (aged 15-18).
• Two-dimensional analysis stratified pitchers into high (>30°) and low (≤30°) CLT groups.
• Assessed trunk rotational mobility and compensatory trunk flexion; correlated with ball velocity and elbow valgus torque.

Main Results:

• No significant differences in trunk rotational mobility or compensatory lateral flexion between high and low CLT groups.
• Contralateral trunk tilt at maximum external rotation moderately correlated with ball velocity (r=0.47, p=0.004).
• Ball velocity strongly correlated with elbow valgus torque (r=0.69, p<0.001).

Conclusions:

• Excessive contralateral trunk tilt in adolescent pitchers is not associated with limited trunk rotation or compensatory lateral trunk flexion.
• The findings suggest that while trunk mobility may not directly explain excessive CLT, the degree of CLT is related to throwing velocity and elbow stress.