Baseball Pitching Arm Three-Dimensional Inertial Parameter Calculations From Body Composition Imaging and a Novel...

Area of Science:

• Biomechanics
• Sports Medicine
• Pediatric Sports Science

Background:

• Baseball pitching studies commonly use inverse dynamics to evaluate arm kinetics, linking high forces to injury risk.
• Previous research has not incorporated participant-specific body segment inertial parameters (BSIPs), potentially limiting accuracy for high-acceleration movements and overweight individuals.

Purpose of the Study:

• To calculate participant-specific BSIPs using dual energy X-ray absorptiometry (DXA).
• To compare pitching kinetics derived from DXA-BSIPs (full DXA-driven) versus scaled BSIPs (scaled inverse dynamics).
• To investigate associations between full DXA-driven kinetics and overweight indices (BMI, SMI).

Main Methods:

• Eighteen 10-11-year-old participants performed fastball pitching, captured via motion analysis.
• Dual energy X-ray absorptiometry (DXA) provided participant-specific BSIPs (mass, center of mass, radii of gyration) for arm segments, BMI, and SMI.
• T-tests and linear regression analyses were employed to address study hypotheses.

Main Results:

• DXA-derived BSIPs significantly differed from scaled BSIPs across all pitching arm segments.
• Shoulder, but not elbow, kinetics showed significant differences between full DXA-driven and scaled inverse dynamics analyses.
• Full DXA-driven shoulder kinetics demonstrated a stronger association with segment mass index (SMI) than body mass index (BMI).

Conclusions:

• Participant-specific BSIPs calculated via DXA offer a more refined approach to inverse dynamics in baseball pitching.
• The use of participant-specific BSIPs and segment mass index (SMI) may enhance the development of evidence-based injury prevention guidelines for youth pitchers.