Iso means the same, and metric means measurement, so isometric exercises are ones where the joints do not change the degree of their angles. A common example is the plank. Before weight lifting took hold of the fitness world, isometrics were a common way to strengthen muscles. Also called muscle control, they are a type of exercise where a specific muscle is contracted for five to ten seconds and then relaxed. Medicinal Martial Arts uses isometrics to safely target and activate individual muscles. They are used in conjunction with leveraged calisthenics to strengthen the body. By targeting specific muscles, we can improve posture and thereby alleviate pain.