THE SKIER'S MUSCULO -TENDINOUS STIFFNESS: A COMPARAISON AMONG TWO DIFFERENT ATHLETIC GROUPS

INTRODUCTION The elastic characteristics of the muscle-tendinous unity constitute an important maker in the field of the performance control. The elastic characteristics of the muscle could be referred to as a “global type” elasticity or to a specific elasticity of the Serial Elastic Component (SEC). In fact, in a stretch-shortening cycle (SSC), the mechanism of storage and restitution of elastic energy from the SEC would be emphasised from a muscle-tendinous unity (MTU) with optimal extensibility and stiffness. In this way it’s possible to store up an acceptable elastic energy quota and in the same time be able to return it in mechanic work during the movement concentric phase. The SEC elastic ideal characteristics would seem to be toward extensibility part of the elastic continuum (Belli and Bosco, 1992). On the contrary a better stiffness of the MTU would be significatively correlated to the concentric and isometric performance (Wilson and coll., 1994). Nevertheless these requisite could be strongly influenced from the specificity of the advised performance. The purpose of this study was to determine the SEC elastic characteristics in two different groups of athletes: the alpine and cross-country skiers, whose sportive performance was characterised by very different neuro-muscular pattern activity.