Final answer:
The less moveable end of a skeletal muscle attachment to a stabilized bone is known as the origin.
Step-by-step explanation:
The less movable end of a skeletal muscle attachment, where the muscle is attached to a stabilized bone, is called the origin. For example, during the action of forearm flexion (bending the elbow), the brachioradialis assists the brachialis muscle where the origin remains stationary allowing the insertion at the forearm to move and bend the elbow joint.
This concept is fundamental in understanding how skeletal muscles function in conjunction with the skeletal system to facilitate movement.