The forces responsible for stretching a muscle can broadly be categorized into active stretching and passive stretching. Active stretching is a type of stretching that involves assuming a position with no assistance other than using the strength of the agonist muscles. The tension of the agonists in an active stretch helps to relax the muscles being stretched (the antagonists) by reciprocal inhibition. An example would be bringing the leg up high and holding it in place without anything (other than the leg muscles themselves) to keep the leg in that extended position. Active stretching is also referred to as static-active stretching.