A Handbook of Health

by Woods Hutchinson

The great group of the voluntary, or bone-moving muscles, which move "with the will" and are under our direct control, may be divided roughly into two divisions—those that move the trunk, or body proper, and run, for the most part, lengthwise of it; and those that move the limbs.

On the body, they may be divided into two great sheets—one running up the front, and the other up the back. When those running up the front of the body contract, they naturally bend the back, and pull the head and shoulders forward and downward. Or, as when you spring up and catch the branch of a tree or a horizontal bar with your hands, these same muscles will pull the lower part of the body and legs upward, so that you can climb into the tree.

The largest and thickest bands of these front body muscles are found over the abdomen, or stomach, where you can feel them thicken and harden when you bend your body forward and pull with your arms, as in hauling on a rope. By their pressure upon the intestines, they give the bowels valuable support, assist in their movements, and help the circulation of the blood through them; so that it is of considerable importance to keep this entire group of muscles well toned up by exercises, such as swinging your arms back over your head, and then down between your legs; bending the head and shoulders backward and forward; swinging the legs up over the body, either when hanging from a bar or lying on your back. Proper exercising and toning up of these muscles will often cure constipation and dyspepsia, by their influence upon the bowels and stomach, and also keep one from taking on fat around the waist too rapidly.

THE MUSCLE-SHEET

Showing how the muscles, overlapping and interlocking, give shape to the body.

On the back of the body, the muscle-sheet has grown into great, thick ropes of muscle on each side of the backbone, which you can feel hardening and softening in the small of the back, when you stoop down or lift weights. These are the muscles that hold the body erect, and keep the back straight when you stand, and are the largest and hardest working group of muscles in the body. Every minute that you sit, or stand, they are at work; and that is why they so often get tired out, and ache, and you say you have "a backache." They have to work harder to keep you erect or upright when you are standing perfectly still than when you walk or run, so that standing perfectly still is the hardest work you can do. Next to standing still, the hardest thing is to sit still, as you probably have found out. If it were not for these great muscles of the back and abdomen, we should double up like a jack-knife, either forward or backward, when we tried to stand up. It is not our skeleton that keeps us stiff or erect, but our muscles.

If you want to keep straight and erect, and thus have a good carriage, you must keep these great body muscles well trained and exercised by swinging movements, such as bending the back forward, standing with your feet apart and then swinging your head and shoulders down and between your legs; or, with your heels together, swinging your hands down till the fingers touch the ground; or by the different exercises that either bend your back, or hold it stiff and erect. Swinging from a bar, rowing, digging with a spade, chopping or sawing wood, dancing, rope-skipping, ball-playing, hop-scotch, and wrestling, all develop these muscles finely and are good for both boys and girls.

Other strands of these muscles branch out to fasten themselves to the shoulder blades and shoulders, where they help to draw the arm back as for a blow, pull the shoulders into position when you stand upright, or, when you have leaned forward and grasped something with the hand, help to pull up the arm and lift it from the ground. These muscles are quite important in holding the shoulders back and giving a good shape to the chest and good carriage of the upper part of the body and head. They are called into play in all exercises like striking, batting, tennis-playing, ball-throwing, swinging, shoveling, swimming, as well as in pulling, in lifting weights, in swinging an axe or handling a broom.