Biomechanics of youth windmill softball pitching.
BACKGROUND
Limited research attention has been paid to the potentially harmful windmill softball pitch. No information is available regarding lower extremity kinetics in softball pitching.


OBJECTIVE
The stresses on the throwing arm of youth windmill pitchers are clinically significant and similar to those found for college softball pitchers.


METHODS
Descriptive laboratory study.


METHODS
Three-dimensional, high-speed (240-Hz) video and stride foot force plate (1200 Hz) data were collected on fastballs from 53 youth softball pitchers. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing-arm elbow and shoulder joints were calculated. Kinetic parameters were compared to those reported for baseball pitchers.


RESULTS
Elbow and shoulder joint loads were similar to those found for baseball pitchers and college softball pitchers. Shoulder distraction stress averaged 94% body weight for the youth pitchers. Stride foot ground reaction force patterns were not similar to those reported for baseball pitchers. Vertical and braking force components under the stride foot were in excess of body weight.


CONCLUSIONS
Excessive distraction stress and joint torques at the throwing-arm elbow and shoulder are similar to those found in baseball pitchers, which suggests that windmill softball pitchers are at risk for overuse injuries. Normative information regarding upper and lower extremity kinematics and kinetics for 12- to 19-year-old softball pitchers has been established.
Werner
Sherry L
SL
Human Performance Laboratory, Tulane Institute of Sports Medicine, 202 McAlister Extension, New Orleans, LA 70118, USA. swerner@tulane.edu
Guido
John A
JA
McNeice
Ryan P
RP
Richardson
Jasper L
JL
Delude
Neil A
NA
Stewart
Gregory W
GW
D000293:Adolescent; D000328:Adult; D001484:Baseball / Q000502:physiology*; D001696:Biomechanical Phenomena; D002648:Child; D004551:Elbow Joint / Q000502:physiology*; D005260:Female; D006801:Humans; D007698:Kinesis / Q000502:physiology; D016059:Range of Motion, Articular; D012399:Rotation; D012785:Shoulder Joint / Q000502:physiology*; D014741:Video Recording