Abstract
Softball pitchers with a high body-fat percentage (bf%) can often be
successful, despite the heightened risk of injury associated with high
bf%. Given the importance of propulsion during pitching, those with high
bf% may have an advantage performance-wise. Therefore, the purpose of
this study was to examine the differences in ground reaction force (GRF)
development between two groups of pitchers: those with a high-fat percentage
(≥32 bf%) and a healthy-fat percentage (<32
bf%). Thirty-two female high-school softball pitchers
(1.70±.06 m, 76.09±17.50 kg,
15±1 yrs) completed dual-energy x-ray absorptiometry (DEXA)
scans. GRF data were collected during pitch propulsion via a force plate, pitch
speed was captured using a radar gun, BMI was calculated from pitcher height and
mass, and fat free mass index (FFMI) and fat mass index (FMI) were calculated
using DEXA data and pitcher height. Multivariate analysis of variance revealed
pitcher group GRFs differed significantly (F3,30=3.45,
p=.030). Univariate follow-up analyses showed healthy bf%
pitchers presented greater weight-normalized peak medial GRF
(F1,30=7.17, p=.012). BMI and FFMI were positively
associated with pitch speed while bf% and FMI were negatively associated
with pitch speed. While pitchers can be successful and carry excess bf%,
results indicate potential performance disadvantages associated with having an
increased bf%.
Key words
ball speed - biomechanics - body composition - kinematics - kinetics - performance improvement
