what triceps muscle has an origin within the shoulder joint
Triceps Brachii Muscle (Long Head). The long head of the triceps brachii muscle is a muscle of the back of the arm, originating from the scapula and shoulder to insert at the elbow.The triceps brachii has three heads (connective immovable muscle) and is the only muscle on the back of the upper arm.It connects the humerus (upper arm bone) and the scapula (shoulder blade) to the ulna (longest of the forearm bones) and is the primary extensor of the elbow.lick to read more below. The long head of the triceps brachii muscle is a muscle of the back of the arm, originating from the scapula and shoulder to insert at the elbow. The triceps brachii has three heads (connective immovable muscle) and is the only muscle on the back of the upper arm.