The Contribution of Muscle Cross-Sectional Area to Jump Height in Collegiate Athletes
PURPOSE: To determine the relative contribution of vastus lateralis (VL) and lateral gastrocnemius (LG) cross-sectional area (CSA) to countermovement jump height (JH) in collegiate athletes. METHODS: Sixty-nine male (n=33, 20.43 ± 1.68 y, 180.34 ± 11.39 cm, 77.54 ± 14.45 kg) and female (n=36, 19.79 ± 1.09 y, 168.46 ± 10.07 cm, 67.33 ± 9.48 kg) collegiate athletes competing in basketball, tennis, cross-country, weightlifting, and volleyball were recruited for the study. Testing was conducted as part of an on-going athlete monitoring program. Athletes were tested on measures of VL and LG CSA using β-mode ultrasonography, and JH measured on force platforms sampling at 1000Hz. Jump height was regressed on age, sex, body mass, VL and LG CSA using a simultaneous multiple linear regression after testing regression assumptions. A relative importance analysis was conducted to determine the relative contribution of each independent variable. The alpha level for all analyses was set at p≤0.05. RESULTS: The model explained 48% of the variance in JH (p<0.001, observed statistical power=0.99). Body mass (B=-0.16, p=0.01), sex (B=-5.10, p<0.001), and VL CSA (B=0.66, p<0.001) were statistical predictors of JH. Age, LG CSA, body mass, sex, and VL CSA contributed 3%, 3%, 7%, 32%, and 55% of the total variance explained by the model, respectively. CONCLUSIONS: Vastus lateralis CSA has a greater contribution to JH than LG CSA while controlling for the variance of age, sex, and body mass. Therefore, greater emphasis should be placed on developing VL CSA than LG CSA for athletes whose goal is to improve JH. Athletes who lose body mass without losing VL CSA may also improve JH.
Bazyler, Caleb D.; Goodin, Jacob R.; Whiton, Tara K.; Mizuguchi, Satoshi; and Stone, Michael H.. 2017. The Contribution of Muscle Cross-Sectional Area to Jump Height in Collegiate Athletes. SEACM Annual Meeting, Greenville, SC. https://www.acsm.org/docs/default-source/regional-chapter-individual-folders/southeast/p_2017