Journal of Sports Sciences
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The influence of squat depth on maximal vertical jump performance
Zachary J. Domire & John H. Challis
a b a b
University of Wyoming, Laramie, WY
Biomechanics Laboratory, Pennsylvania State University, University Park, PA, USA Version of record first published: 18 Feb 2007.
To cite this article: Zachary J. Domire & John H. Challis (2007): Theinfluence of squat depth on maximal vertical jump performance, Journal of Sports Sciences, 25:2, 193-200 To link to this article: http://dx.doi.org/10.1080/02640410600630647
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Journal of Sports Sciences, January 15th 2007; 25(2): 193 – 200
The inﬂuence of squat depth on maximal vertical jump performance
ZACHARY J. DOMIRE1 &JOHN H. CHALLIS2
University of Wyoming, Laramie, WY and 2Biomechanics Laboratory, Pennsylvania State University, University Park, PA, USA (Accepted 9 February 2006)
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Abstract An increase in the period over which a muscle generates force can lead to the generation of greater force and, therefore, forexample in jumping, to greater jump height. The aim of this study was to examine the effect of squat depth on maximum vertical jump performance. We hypothesized that jump height would increase with increasing depth of squat due to the greater time available for the generation of muscular force. Ten participants performed jumps from preferred and deep squat positions. A computer model simulatedjumps from the different starting postures. The participants showed no difference in jump height in jumps from deep and preferred positions. Simulated jumps produced similar kinematics to the participants’ jumps. The optimal squat depth for the simulated jumps was the lowest position the model was able to jump from. Because jumping from a deep squat is rarely practised, it is unlikely that thesejumps were optimally coordinated by the participants. Differences in experimental vertical ground reaction force patterns also suggest that jumps from a deep squat are not optimally coordinated. These results suggest there is the potential for athletes to increase jump performance by exploiting a greater range of motion.
Keywords: Computer simulation, biomechanics, coordination, jumpingIntroduction Maximum vertical jumping has received considerable attention in the biomechanics literature (e.g. Alexander, 1990; Challis, 1998; Van Soest, Schwab, Bobbert, & Van Ingen Schenau, 1993), and much is known about optimal performance (Pandy & Zajac 1991). The increase in jump height for jumps commenced with a countermovement, compared with jumps begun from an initial squat position, has been...