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A comparison of bilateral and unilateral drop jumping tasks in the assessment of vertical stiffness

  • Sean J. Maloney
    ,
  • Jo Richards
    ,
  • Iain M. Fletcher
Research Output: Contribution to journal Article Peer-review

Abstract

This study sought to compare vertical stiffness during bilateral and unilateral drop jumping. Specifically, the intersession reliabilities and force-deformation profiles associated with each task were to be examined. On 3 occasions, following familiarization, 14 healthy males (age: 22 [2] y; height: 1.77 [0.08] m; and body mass: 73.5 [8.0] kg) performed 3 bilateral, left leg and right leg drop jumps. All jumps were performed from a drop height of 0.18 m on to a dual force plate system. Vertical stiffness was calculated as the ratio of peak ground reaction force (GRF) to the peak center of mass (COM) displacement. Unilateral drop jumping was associated with higher GRF and greater COM displacement (both Ps < .001), but vertical stiffness was not different between tasks when considering individual limbs (P = .98). A coefficient of variation of 14.6% was observed for bilateral vertical stiffness during bilateral drop jumping; values of 6.7% and 7.6% were observed for left and right limb vertical stiffness during unilateral drop jumping. These findings suggest that unilateral drop jumps may exhibit greater reliability than bilateral drop jumps while eliciting similar vertical stiffness. It is also apparent that higher GRFs during unilateral drop jumping are mitigated by increased COM displacement.

Publication Information

Output type

Research Output: Contribution to journal Article Peer-review

Original language

English

Pages from-to (Number of pages)

Pages 199-204

Journal (Volume, Issue Number)

Journal of Applied Biomechanics (Volume 34, Issue 3)

Publication milestones

  • Published - 01/06/2018

Publication status

Published - 01/06/2018

ISSN

1065-8483

External Publication IDs

  • handle.net: 10547/623628
  • Scopus: 85049093142

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