Relationship between time to peak torque of hamstrings and sprint running performance

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 theirfindings 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.