Choose from Three Options
- $39 for one 60-minute therapeutic massage ($75 value)
- $49 for one 90-minute therapeutic massage ($100 value)
- $135 for three 60-minute therapeutic massages ($225 value)
Muscular System: The Meat of the Matter
The joys of a massage or the relief of a chiropractic adjustment—and the stresses of physical work—play out partly in the muscles. Learn just what pumps the body up with Groupon’s guide to the muscular system.
The human body has more than 630 muscles keeping it upright and mobile. They make up almost half its weight and power the movements of the bones, the blood, and even the food in the stomach. Perhaps the most familiar muscles are those seen in bodybuilding contests and facial-expression contests: the skeletal, or voluntary, muscles. They’re attached to our bones and controlled by our brains, which zap them with electrical signals to cause their fibers to contract. During a muscle contraction, filaments inside the muscle fibers slide together, stacking up on one another so that the larger fiber shortens. In shortening, the fibers gain thickness—a phenomenon we notice as flexing. Whatever muscles do, they accomplish by this single pulling action. If a bicep (part of a category of muscles known as flexors) flexes to lift a barbell, it needs a tricep (an extensor), pulling in the opposite direction, to bring the arm back down.