Origin and Insertion

ORIGIN AND INSERTION

When a muscle contracts (flexes), it pulls on the bones and makes one of them move (i.e. the Radius in the example).

The tendon at one end is attached to a non-moving part : the "ORIGIN" (the SCAPULA is the origin in this example).

The tendon at the other end is attached to the moveable bone : "the INSERTION" (the RADIUS in this example) which is the part of the body activated by the muscle.