The lateral head refers to one of the three parts of the triceps brachii muscle, located at the back of the upper arm. It is situated on the outer side of the arm and plays a crucial role in extending the elbow joint. This muscle is essential for various activities, such as pushing and lifting. The lateral head works alongside the other two heads, the long head and the medial head, to provide strength and stability during arm movements. Strengthening the lateral head can improve overall arm function and enhance athletic performance in sports that require upper body strength.