A Theory of Muscle Mechanism

Abstract

IN an article in the magazine Cheap Steam, which has been reprinted in pamphlet form, Walter Gold-stern has put forward a theory as to the methods by which muscles operate. The muscle is described as an engine transforming the calorific energy of food into power and heat. Structurally, the muscle is formed of a large number of fibres about 2 in. long and 1/500 in. in diameter, each consisting of many fibrils bound together by an elastic covering, the sarcolemma. By the operation of a nerve, one or more bundles of fibrils, according to the power required, are caused to contract. The author sets himself to supply an answer to the question as to the mechanism by which the muscle fibre is caused to contract. This, he says, is effected by a small internal pressure. He compares the sarcolemma to a long, narrow tube closed at both ends into which liquid under pressure is pumped. As the pressure increases, the tube becomes enlarged centrally and adopts a barrel shape, and would tend ultimately to become spherical. It is suggested that this central distension is accompanied by diminution in length ; but this rather doubtful point is not cleared up, and if it were admitted it would still require to be shown that it would occur against the pull which the muscle is understood to be exerting ; and also the method by which the pressure is produced and where the added liquid necessary to produce it can come from. A more acceptable explanation is conveyed in the suggestion that this central expansion of the sarcolemma is made to aid the lengthwise contraction by what is called lever action, but which might more suitably be described as the bowstring effect. of the muscle fibres being pulled apart at the centre and producing a considerably magnified endwise pull.