Affiliations: [a] Department of Track and Field, Faculty of Sport,
University of Ljubljana, Slovenia | [b] Department of Sports Medicine, Faculty of Sport,
University of Ljubljana, Slovenia | [c] Institute of Occupational Safety, Ljubljana,
Slovenia
Abstract: Background: Previous studies have investigated the role of
hamstrings and quadriceps absolute and/or relative peak torque at high
concentric velocities (240° and 300°/sec) and sprint performance
but their findings were inconclusive. However, no study so far has investigated
the relationship between time to peak torque (TPT) of hamstrings and quadriceps
at high concentric velocity and sprint ability. This parameter may play and
important role in sprinting, as it is one of the indicators of the explosive
muscular strength that is crucial for sprinting performance. Method: Thirty six healthy physical education students without previous injury
voluntarily participated in investigation. The measurements of the sprint times
at 5, 10 and 20 meters were carried out using an infrared photocell. Quadriceps
and hamstrings strength was tested concentrically at 240°/sec using
Biodex System 3 dynamometer. Linear regression was used to evaluate the
influence of hamstrings and quadriceps relative strength and TPT on sprint
times at 5, 10 and 20 meters. Results. Hamstrings' TPT significantly
predicted the sprint times at 5, 10 and 20 meters (p values were 0.001, 0.004
and 0.008, respectively). At 5, 10 and 20 meters the model was significant (F
=7.12, p<0.01; F=5.31, p< 0.05; F=4.07, p<0.05,
respectively) while R square values were 0.31, 0.26, and 0.21, respectively.
Subjects with hamstrings TPT below 200 ms had significantly shorter sprint
times at all sprint distances in comparison with subjects whose hamstrings TPT
was above 200 ms. Quadriceps' TPT was not correlated with sprint times. Conclusion: The ability of the hamstrings to produce torque quickly can
significantly influence the sprint times at 20 m sprint. Most of this effect is
seen in the initial acceleration phase (first 5 m) while later on (at 10 and
20 m) this influence slightly decreases but remains significant. It seems that
not only the absolute amount of strength, but also the rate of strength
development within the muscle can influence the sprint times.
