Degree Name

PhD (Doctor of Philosophy)


Sport Physiology and Performance

Date of Award


Committee Chair or Co-Chairs

Satoshi Mizuguchi

Committee Members

Caleb D. Bazyler, Jeremy A. Gentles, Michael H. Stone


Purpose: To compare muscle architecture variables between sport and sex in competitive athletes, and to compare muscle architecture with performance variables in strong versus weak athletes, and good versus poor jumpers. Methods: The vastus lateralis (VL) and lateral gastrocnemius (LG) muscles of 139 collegiate athletes were collected using ultrasonography to determine muscle thickness (MT), pennation angle (PA), fascicle length (FL), and relative fascicle length (FLrel). Absolute and relative peak power, absolute and relative isometric peak force, and jump height were measured in a subset of baseball and soccer athletes. A 5x2 factorial analysis of variance (ANOVA) was used to investigate differences in group means between sex and sport for muscle architecture variables in the larger cohort. A 2x2 factorial ANOVA was used in the in the smaller cohort to investigate differences between strong and weak athletes, and good and poor jumpers. Results: Significant main effects were observed for sex in VL muscle thickness (MT), VL pennation angle (PA), LG MT, and LG fascicle length (FL). Significant main effects were observed for sport in VL MT, VL FL, VL relative fascicle length (FLrel) and LG MT. Significant interaction effects were observed for LG PA and LG FLrel. Muscle architecture profiles were significantly different between strong and weak, and good and poor jumpers in baseball, but not soccer athletes. Soccer athletes had greater PA but smaller FL than baseball athletes. Conclusions: Muscle architecture may play a role in sport selection, undergoes directed adaptation to sport specific training demands, and may differentiate between high and low performers in more anaerobic athletes. Males had greater muscle thickness than females. Patterns of PA and FL values between sport and sex differed between VL and LG. More aerobic athletes such as soccer athletes may have greater VL PA and smaller VL FL than more anaerobic athletes such as baseball athletes.

Document Type

Dissertation - unrestricted


Copyright by the authors.