Exercise in education and medicine / by R. Tait McKenzie.

  • R. Tait McKenzie
Date:
1909
Catalogue details

Licence: Public Domain Mark

Credit: Exercise in education and medicine / by R. Tait McKenzie. Source: Wellcome Collection.

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    exercises of endurance, consisting of motions rhythmically repeated without great muscular expenditure for each one, and depending for their effect upon continuous repetition. Exercises of effort may be more or less violent in character or compound in motion, each one starting from and ending with rest. They are in endless variety, from simple movements of lifting and throwing, to the complicated combinations on the parallel bars and horizontal bar. In them the element of skill plays a leading role, and what would be a mild exercise for the expert may be a severe strain to the beginner, whose inaccuracy means the clumsy employment of many muscles that help little in its accomplish¬ ment, the contraction of some groups actually retarding success. Even in the accurate performance of an apparently simple move¬ ment, the distribution of muscular effort is wide, and increases tremendously with the difficulty of the feat. In pushing a heavy dumb-bell to arm’s length above the shoulder, the extensors of the elbow-joint are the ones usually considered, but the entire muscular system shares in the effort. The grasping muscles of the hand are required, also the muscles that raise the shoulder and rotate the scapula. These are attached to the spine and ribs, which in turn must be supported by the pelvis, steadied on the hips, while the balance of the body is preserved by the muscles of the thigh and legs. A single, simple effort, then, may give rise to fatigue of more than the muscles most obviously employed. Education should be directed to teaching skill in the per¬ formance of such movements—skill that tends to economize the amount of effort required—for it is the common experience of shot- putters to find that their record performance is accomplished with the greatest ease, owing to the smooth, accurate application of group after group of muscles at the proper time; and the perfec¬ tion of balance and speed of the body’s movement. However skilful the performer may be, the whole muscular system participates in any violent exercise of effort. During the intense concentration so necessary for success, the chest-walls are fixed; the glottis is closed, the lungs acting as an air cushion