Effects of medial longitudinal arch flexibility on propulsion kinetics during drop vertical jumps

Corey D Grozier; Gretchen K Cagle; Lauren Pantone; Kyle B Rank; Samuel J Wilson; John R Harry; Samantha Seals; Jeffrey D Simpson

doi:10.1016/j.jbiomech.2021.110322

Effects of medial longitudinal arch flexibility on propulsion kinetics during drop vertical jumps

J Biomech. 2021 Mar 30:118:110322. doi: 10.1016/j.jbiomech.2021.110322. Epub 2021 Feb 11.

Authors

Corey D Grozier¹, Gretchen K Cagle², Lauren Pantone², Kyle B Rank², Samuel J Wilson³, John R Harry⁴, Samantha Seals⁵, Jeffrey D Simpson⁶

Affiliations

¹ Department of Movement Sciences and Health, University of West Florida, Pensacola, FL, United States; Department of Kinesiology, University of North Alabama, Florence, AL, United States.
² Department of Movement Sciences and Health, University of West Florida, Pensacola, FL, United States.
³ Department of Health Sciences and Kinesiology, Georgia Southern University, Statesboro, GA, United States.
⁴ Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, United States.
⁵ Department of Mathematics and Statistics, University of West Florida, Pensacola, FL, United States.
⁶ Department of Movement Sciences and Health, University of West Florida, Pensacola, FL, United States. Electronic address: jsimpson1@uwf.edu.

PMID: 33607594
DOI: 10.1016/j.jbiomech.2021.110322

Abstract

This study examined the effects of medial longitudinal arch (MLA) flexibility on kinetics during the eccentric and concentric subphases of a drop vertical jump (DVJ). Physically active adults with flexible (n = 16) and stiff (n = 16) MLA completed DVJs onto a force platform from a height of 30 cm. Eccentric and concentric subphases of the DVJ were identified from the vertical ground reaction force (GRF) data. Jump height, ground contact time, reactive strength index (RSI), vertical center-of-mass depth, vertical stiffness and time of the eccentric and concentric subphases were evaluated. Amortization force, peak vertical GRF and vertical impulse were also obtained for the eccentric and concentric subphases of the DVJ. Dependent variables were compared between groups using independent samples t-tests (p < 0.05). Significantly greater vertical stiffness (p = 0.048; ES = 0.63) was found in the stiff arch group (-173.91 ± 99.73 N/kg/m) compared to the flexible arch group (-122.95 ± 63.42 N/kg/m). A moderate-magnitude difference (ES = 0.58) was observed for RSI between flexible (0.89 ± 0.39) and stiff arch (1.20 ± 0.70) groups, but was not significant (p = 0.063). The active and passive structures supporting the MLA may be used differently to achieve similar vertical jump height during a DVJ. Additional research is warranted to further understand the contributions of MLA flexibility to jumping performance.

Keywords: Foot structure; Ground reaction force; Jump performance; Locomotion.

MeSH terms

Biomechanical Phenomena
Foot*
Kinetics