Relationship of Abdominal Oblique Strength on Biomechanics in Adolescent Baseball Pitchers.

Context: The pitching cycle is a highly dynamic task, and the trunk and abdominal obliques are key contributors in efficient kinetic transfer.

Objective: To determine the relationship between abdominal oblique strength and pitching biomechanics in adolescent baseball pitchers.

Design: Cross-sectional study.

Setting: Biomechanics laboratory.

Patients or other participants: Nineteen healthy right-handed high school male baseball pitchers (age = 17.1 ± 1.1 years, height = 183.7 ± 6.5 cm, mass = 83.1 ± 10.1 kg).

Main outcome measures: The main outcome was full body biomechanics captured at key points during the pitching cycle. The main variable of interest was abdominal oblique strength (glove arm and throwing arm). Kinematics and kinetics were calculated using Visual 3D motion capture software. Descriptive statistics including means and standard deviations were calculated. Shapiro-Wilk test confirmed the data were normally distributed. Scatterplots determined linear associations, so a 2-tailed Pearson correlation with Fisher option was used to examine associations between obliques strength measurements and biomechanical metrics.

Results: Three kinematic measures were identified with p < 0.05 and r = 0.5 demonstrating strong correlations with abdominal oblique strength. Maximum pelvis rotation velocity was positively correlated with throwing arm oblique strength (r =0.52, p = 0.02). Glove arm oblique strength was positively correlated with both maximum pelvis rotation velocity and maximum torso rotation velocity (r = 0.69, p = 0.001, and r = 0.52, p = 0.02, respectively).

Conclusions: These data highlight the moderate to strong positive relationship abdominal oblique strength has on both maximal pelvic and torso rotational velocity. Training to improve the strength of the abdominal obliques may increase both maximal pelvic and trunk rotational velocity, while avoiding a significant increase upper extremity joint loading, which is important in optimizing performance and injury prevention.