Abstract
Researchers suggest that motion deriving energy from the more proximal segments of
the body is important to reduce injury susceptibility. However, limited clinical assessments
have been associated with efficient energy flow within a complex movement such as
the baseball pitch. This research aimed to determine the relationship between glenohumeral
stability as determined by the closed kinetic chain upper extremity stability test
and energy transfer into and out of the humerus during the baseball pitching motion.
Kinematic and kinetic data were collected at 240 Hz on twenty-four baseball pitchers.
Participants performed the closed kinetic chain upper extremity stability test prior
to throwing three fastballs at game speed to a catcher with the fastest fastball used
for analysis. Spearman’s Rho were used to examine relationships between energy flow
in and out of the humerus with glenohumeral stability as determined by the average
score and normalized stance width during the closed kinetic chain upper extremity
stability test. There was a significant negative correlation between the average score
and normalized peak power leaving the humerus (r
s[22]=−0.42, p=0.04). This result provides preliminary support for the use of the closed
kinetic chain upper extremity stability test as a clinical assessment of a pitcher’s
ability to efficiently transfer energy within the upper extremity during the pitch.
Key words
biomechanics - pitching - proximal stability - stability assessment
