The medial head refers to one of the three parts of the triceps brachii muscle, located at the back of the upper arm. It plays a crucial role in extending the elbow joint, allowing for movements such as pushing and lifting. The medial head is situated deeper than the other heads, which are the lateral and long heads. This muscle head is particularly important for stabilizing the arm during various activities. It contributes to overall arm strength and is engaged in many daily tasks, making it essential for functional movements and athletic performance.