Abstract
Despite evidence that overuse is the most common mechanism of injury, softball pitchers
currently have no pitch count regulations. Pain has been associated with certain pitching
pathomechanics, and some reports indicate increased pain following a single pitching
bout. Therefore, the purpose of this study was to examine trunk and lower extremity
kinematics during the first and last inning of a game, as well as last inning pitch
volume in youth softball pitchers. Thirty-two youth softball pitchers (12.4±1.6 years,
159.4±8.9 cm, 62.0±13.6 kg) pitched a simulated game. Three fastballs were averaged
and analyzed from the first and last inning. Kinematic data were collected at 100Hz
using an electromagnetic system, synced with motion analysis software. A Wilcoxon
signed rank test revealed pitchers exhibited less trunk rotation toward their pitching
arm side in the last inning. A bivariate Pearson’s correlation showed volume of pitches
was correlated with stride length (r=0.367, p=0.039) and center of mass (r=0.364,
p=0.041) at the start of the pitch, and trunk flexion at top of pitch (r=−0.392, p=0.026),
foot contact (r=−0.413, p=0.019), and follow-through (r=−0.436, p=0.013). This study
found that pitching a simulated game did result in altered pitching mechanics, meanwhile
pitch volume was also correlated with pitching mechanics.
Key words
Injury - pitch count - trunk pathomechanics
