Why? The Science of Athletics

MECHANICS AND LEVERAGE 301 runners. It is only those athletes who expend their force mainly downwards into the ground, and therefore have small forward reaction, who show an unsightly, jerky style of running. Style is often held to lurk in the eye of the beholder, but style is synonymous with pure mechanics and should be judged in relation to how the direction of the move, ments is controlled, the carriage of the body, the applica– tion of force to the ground, and the timing for a climax which produces the power at its optimum without wasteful effort. Any good coach can check the mechanics of his pupils by such criteria, but he needs to know more about the internal mechanics of muscular action before he can form his final opinion. The late Sam Mussabini, doyen of British coaches, and Lawson Robertson, the American Chief Olympic Coach, have both insisted upon the importance of the quadriceps muscle in fast sprinting, and have stressed the fact that quick recovery of the leg is largely governed by the action of the thigh flexors (p.soas and illiacus). The front of the thigh muscles, as we have seen, serve to generate a powerful downwards drive, through the quadriceps help– ing to lift the leg and straighten the knee ; but the push from the ground is of great importance also, and here the force of propulsion comes from the leverage generated by the action of the posterior thigh muscles (hamstrings) a;nd ·the muscles of the buttocks (glutei). It is the contraction of the calf muscles (gastrocnemeus and soleus) which supply the final leverage so that the foot is straightened and the runner rises upon his toes. For leverage to be fully efficient, however, the levers must have a firm base upon which to act. Therefore we find that the alignment of the body and its running angle is controlled largely by the muscles of the back, aided by the abdominal muscles, which hold the pelvis firm to supply a proper base for the forceful action of the leg muscles and the functions of leverage.