A Quantitative Analysis of Ground Contact Time, Impulse, and Average Force in Various Plyometric Exercises

Abstract

Objective: Hurdle hops and jumping variations have been utilized as explosive, reactive movements by strength coaches to prepare their athletes and optimize their rate of force production. The purpose of this study was to analyze the differences in ground contact time and impulse between hurdle hops and two separate jump variations. The objective is to provide sports performance professionals with a quantitative analysis of these movements to enhance the quality and overall effectiveness of their training regimens. Methods: Eighteen Division l male ice hockey players participated to assess differences in ground contact time, impulse, and average force produced between hurdle hops (18") and two jump variations: Antagonistically Facilitated Specialized Movement (AFSM) and Depth Drop Jump (DDJ). Participants were familiarized with each of the two jump variations and the hurdle hop prior to testing. Hurdle hop data was collected in two trials for each of the first and third hurdle hops. Jump data was collected in two trials for each of the two jump variations. Results: Paired-sample t-tests displayed significant differences between hurdle hops (HH) and AFSM jumps in movement time (p=0.000, HH=0.221s ± 0.039s, AFSM=0.430s ± 0.062s), impulse (p=0.000, HH=633N*s ± 65N*s, AFSM=777N*s ± 88N*s) and average force (p=0.000, HH=2905 ± 354N, AFSM=1827 ± 198N). Additionally, there was significant differences between HH and DDJ in movement time (p=0.000, HH=0.221s ± 0.039s, DDJ= 0.367 ± 0.055), impulse (p=0.000, HH=633N*s ± 65N*s, DDJ=768N*s ± 85N*s), and average force produced (p=0.000, HH=2905 ± 354N, DDJ=2115N ± 213N). Conclusion: Findings support significant differences when performing hurdle hops in comparison to the performance of an AFSM jump or a DDJ. While the change in momentum (impulse) is greater in both jump variations when measured against the hurdle hops, the movement time and average force produced throughout the movement is less in the hurdle hops than in the jump variations. Sports performance professionals could use these quantified differences to appropriately cater exercises based on the desired training parameter.