The upper arm consists of the deltoids, biceps, as well as the triceps. The movement is initiated by leaning forwards and loading the deltoids and triceps. The long head of the triceps brachii inserts inferiorly, similarly. Some consider anconeus to be a continuation of the triceps brachii muscle. Passive flexion of elbow meets immediate resistance due to stretch reflex in the triceps muscle. This is where the lateral head of "triceps brachii" is attached. The three muscles have been referred to as the triceps coxae. The other three are the triceps, anconeus, and extensor carpi radialis longus. It is used to perform triceps extensions and hammer curls. This action is performed by triceps brachii with a negligible assistance from anconeus. In humans, the anconeus is sometimes loosely called "the fourth head of the triceps brachii". During Spring training, Darvish began to experience soreness in his right triceps. Ruptures of the triceps muscle are rare, and typically only occur in anabolic steroid users. It is important to work the triceps muscle through its full range of contraction. He sustained chest, shoulder and triceps injuries, ruling out further records in the bench press.