Related Experiment Videos
Shoulder muscle firing patterns during the windmill softball pitch
M W Maffet1, F W Jobe, M M Pink
1Centinela Hospital Medical Center, Inglewood, California 90301, USA.
The American Journal of Sports Medicine
|May 1, 1997
Summary
This study analyzed shoulder muscle activity in female softball pitchers, revealing key roles for muscles like the supraspinatus and pectoralis major during the windmill throw. Similarities were found with baseball pitching mechanics, particularly in serratus anterior and pectoralis major function.
Area of Science:
- Biomechanics
- Sports Medicine
- Human Movement Science
Background:
- The windmill softball pitch involves complex shoulder kinematics.
- Understanding shoulder muscle activation is crucial for injury prevention and performance enhancement in pitchers.
Purpose of the Study:
- To describe the electromyographic activity of eight shoulder muscles during the windmill fast-pitch softball throw.
- To compare shoulder muscle function in softball pitching to known baseball pitching mechanics.
Main Methods:
- Intramuscular electromyography (EMG) was used to measure muscle activity.
- High-speed cinematography and motion analysis captured kinematic data.
- Ten collegiate female softball pitchers participated in the study.
Main Results:
- Supraspinatus muscle activity peaked during arm elevation (6 to 3 o'clock), aiding humeral head centralization.
- Posterior deltoid and teres minor muscles were active from 3 to 12 o'clock for arm elevation and external rotation.
- Pectoralis major accelerated the arm, while serratus anterior optimized scapular positioning and subscapularis acted as an internal rotator and stabilizer.
Conclusions:
- Shoulder muscle activation patterns in softball pitching show functional similarities to baseball pitching, especially for the serratus anterior and pectoralis major.
- The infraspinatus and teres minor exhibit distinct activation patterns, with infraspinatus acting more independently below 90 degrees.
- Subscapularis muscle plays a vital role in anterior glenohumeral stabilization and internal rotation during pitching.