INCREASES IN SEGMENT OR IMPLEMENT VELOCITY: A BIOMECHANICAL PERSPECTIVE

Abstract

The coach, who both understands the mechanical aspects of a skill, can analyse movement and is also able to communicate with athletes will provide the best opportunity for optimal development with minimal risk of injury. The same coach will however, often be posed the question of how to enable pupils to develop higher segment or implement velocity in hitting/kicking or body movements such that: they are able to hit or kick a ball with a higher velocity, while still maintaining an acceptable level of control in sports such as tennis, golf, squash, baseball, soccer or rugby; they can generate higher limb velocities to enable higher release velocities in general throwing or discus and javelin events; they are able to apply more force to an implement (oar or pedal) or medium (water) to propel the body. This paper introduces five important considerations, integral to the teaching of high velocity movement. First, the use of elastic energy in performance augmentation will be investigated with special consideration given to the timing of the stretch - shorten cycle. Research findings on the influence of timing between the stretch and shorten phases of a movement and on the recovery of the stored energy will be discussed. Secondly, the role of displacement (backswing or series of preparatory movements) to increase the distance over which velocity may be developed during the forwardswing will be investigated. The use of coordinated movement between body segments will then also be discussed with reference to achieving high end point velocities. Differences in the way segments interact can account for variations in the timing of segment actions across skills and these differences will be examined and the general principles governing the sequencing of motion discussed. The influence of increasing muscle strength/endurance on improving segment rotational velocity will also be examined as a means of increasing end-point velocity. Equipment design may also play a role in increasing the rebound velocity characteristics of a ball in striking skills. The implications to performance of changes in design characteristics will be briefly discussed. This paper, by reviewing research paper in each of these five broad areas, provides the biomechanist with a theoretical framework which can be presented to coaches so they can better understand modification to technique that may be required if an athlete wishes to produce a higher segment or implement velocity. The practical implications for coaches, in a variety of sports, in each of these areas will also be presented.