The results of the current study allow the conclusion that the execution of the contact phase is the key generator, which is connected with maximal sprinting velocity. The contact phase should be as short as possible and realised in such a way that there is the least possible reduction in the horizontal velocity of CG in the braking phase. An economic execution of the braking phase depends mostly on the grabbing velocity of the thigh and the foot just before touchdown. In light of this, training should be oriented into developing quick and reactive power and practising the technique of movement with the swing leg in the front support phase. A high grabbing velocity of the swing leg has, as a consequence, a higher stride rate that directly affects the result in sprinting. The function of the shank muscles is especially important. Their electrical activation begins before touchdown. Necessary stiffness of the muscles that must resist the force of the surface in the forward support phase is ensured in this way. According to the EMG results, m.biceps femoris is a very important muscle in the biomechanics of sprinting. Its activity in the contact phase lasts longest of all the monitored muscles. Its main role in the forward support phase is to ensure the greatest possible grabbing velocity of the leg in the sprinting stride.
Who were they studying exactly? Who put the study on? I don’t like the sound of the word “Grabbing.” As Charlie has pointed out many times, a grabbing or clawing motion of the ground will increase GCT and cause the hips to lower.