Why? The Science of Athletics

CONSIDERATIONS IN CONDITIONING ATHLETES 19 hundreds of long and very fine fibres, not one of them more than a tenth of the thickness of a human hair. The nerves with which we feel and those that carry the impulses from the brain to the muscles have each a separate fibre with a cover and an inside, in the same way as electric wires are.insulated. If the dead frog is skinned and its leg tissues are separated, the sciatic nerve may be identified, as a small white thread lead– ing from the spinal column to the calf muscle(gastrocnemius). This nerve and the muscle to which it is attached can be re– moved, since the frog is dead, and the nerve itself will remain suf– ficiently alive to serve for experimental pur- · ~ · poses for several hours. Fig. I shows how FIG. I the bone (femur), to which the calf muscle (gastrocnemius) is attached, may be held in a clamp. The sciatic nerve, – as shown, should be dissected right out from the spinal column to its entry into the muscle, and the branches which do not actuate the gastrocnemius should be severed. The muscle depends from the bone, with a hook placed through the tendon a~ the lower end for the purpose of recording and measuring movements. It is, broadly _ speaking, the motor nerve-cells of - the spinal column which transmit orders to the muscles ; the higher parts of the nervous sys-tem are contained within the skull. The discovery of how muscular movement was brought about did not, however, take the athletic research scientist nearly far enough. The trained muscle showed longer amplitude of contraction, better blood supply