ANATOMY

Long head originates from the Infraglenoid Tubercle of Scapula (shoulder blade) and ends in the anterior of Teres Minor (narrow elongated muscle of Rotator Cuff) and posterior of Teres Major (rounded muscle of upper limb).

Medial head originates from the distal groove of the Radial Nerve , dorsal surface of Humerus, from Medial Intermuscular Septum and Lateral Intermuscular Septum. Long and Lateral Heads cover it.

Lateral head originates from the  dorsal surface of humerus, which is on the lateral side of the Radial Nerve. It also arises from the greater tubercle of the Lateral Intermuscular Septum.

INNERVATION

All heads of the Triceps Brachii Muscle are innervated by the Radial Nerve. Long Head is also innervated by the Axillary Nerve.

BLOOD SUPPLY

The blood and nutrient supply to the muscle is provided by the Deep Brachial Artery.

FUNCTION

Triceps muscle is an antagonist to the Biceps and Brachialis (muscle in upper arm) muscles and its main function is to act as an extensor muscle for Elbow Joint. It also helps in fixation of elbow when hand and forearm are in use for example when writing.

CLINICAL SIGNIFICANCE

The common injury to the Triceps Brachii Muscle is the Triceps Strain. It usually occurs in a region where muscle and tendon meets being the weakest point of the muscle. The common symptoms for it are as follows.

• Muscle inflammation

• Swelling

• Pain

• Inability to freely move the muscle