Muscle Groups of the Upper Arm: Biceps and Triceps Brachii

Anatomy and Structure of the Triceps Brachii

The triceps brachii is a three-headed muscle located at the posterior aspect of the upper arm. It plays a critical role in the extension of the elbow joint and is essential for various functional movements.

Structure of the Triceps Brachii

• Long Head: Originates from the infraglenoid tubercle of the scapula.
• Lateral Head: Arises from the posterior surface of the humerus, superior to the radial groove.
• Medial Head: Originates from the posterior humerus, inferior to the radial groove.

Function

The primary function of the triceps brachii is to extend the forearm at the elbow joint. Additionally, the long head assists in shoulder extension and stabilization.

Clinical Importance

Weakness or injury to the triceps can lead to compromised arm function. Conditions such as triceps tendonitis and triceps rupture require medical attention and rehabilitation.