Affiliations: [a] School of Health Professions, Plymouth University, Plymouth, UK
Note: [] Corresponding author: Dr. Gary Shum, Ph.D., Plymouth
University, School of Health Professions, Peninsula Allied Health Centre,
Derriford Road, Plymouth PL6 8BH, UK. Tel.: +44 1752 588808; Fax: +44 1752
588874; E-mail: [email protected]
Abstract: OBJECTIVE: The aim of this study was to investigate how
isokinetic lower limb strength and velocity of knee and hip extension correlate
to vertical jump performance in university team rugby players. METHODS: Twenty asymptomatic university team rugby players performed a maximal vertical
jump test, in which the vertical displacement was measured from maximum
standing reach height to maximal height attained from a countermovement jump. A
dynamometer assessed the maximal isokinetic strength and velocity of hip and
knee extension in the dominant leg. Peak torque was measured when participants
moved at angular velocities of 60 and 120°/s for hip extension, and 120
and 240°/s for knee extension. The highest velocity achieved during
isokinetic hip and knee extension up to a maximum level of 360°/s was recorded. RESULTS: Moderately strong correlations were found between knee
extension strength and vertical jump height, particularly when testing at
faster angular velocities of 240°/s (R=0.609, p=0.002). There was
also a significant moderate correlation between maximum knee extension speed
and vertical jump height (R=0.540, p=0.007). CONCLUSIONS: The results suggest that focusing on strength/power training of the knee extensors
at a high speed may result in improved vertical jump performance.
