The relationship between vertical stiffness during bilateral and unilateral hopping tests performed with different strategies and vertical jump performances

ABSTRACT

Vertical stiffness has been highlighted as a potential determinant of performance and may be estimated across a range of different performance tasks. The aim of the current study was to investigate the relationship between vertical stiffness determined during 9 different hopping tests and performance of vertical jumps. Twenty healthy, active males performed vertical hopping tests with three different strategies (self-selected, maximal, and controlled) and three different limb configurations (bilateral, unilateral preferred, and unilateral non-preferred), resulting in nine different variations, during which vertical stiffness was determined. In addition, participants performed squat jump (SQJ) and countermovement jump (CMJ) during which jump height, CMJ stiffness, and eccentric utilization ratio (EUR) were determined. Vertical stiffness in bilateral and unilateral preferred tasks performed with a self-selected and maximal, but not controlled, strategy was associated with stiffness in the CMJ (r = 0.61–0.64; p < 0.05). However, stiffness obtained during unilateral preferred and non-preferred hopping with self-selected strategy was negatively associated with performance in SQJ and CMJ tasks (r = −0.50 to −0.57; p < 0.05). These findings suggest that high levels of vertical stiffness may be disadvantageous to static vertical jumping performance. In addition, unilateral hopping with a self-selected strategy may be the most appropriate task variation if seeking to determine relationships with vertical jumping performance.

Highlights

• Stiffness obtained during unilateral hopping with a preferred strategy was negatively associated with vertical jumping performances

• Stiffness obtained during hopping with preferred and maximal strategies was associated with stiffness obtained during a countermovement jump

• In this population, hopping stiffness may therefore be reflective of an individual's countermovement jump strategy

• High levels of stiffness may be disadvantageous to static-start vertical jumping

KEYWORDS:

• Vertical stiffness
• hopping
• performance

Acknowledgements

The authors would like to thank the physical education students of Kharazmi University who volunteered to participate in the study.

Disclosure statement

No potential conflict of interest was reported by the author(s).