Radial groove

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Radial groove is an anatomical feature located on the posterior aspect of the humerus, which is the long bone in the upper arm. This groove, also known as the radial sulcus, accommodates the radial nerve and the deep brachial artery as they traverse the arm. The radial groove plays a crucial role in the neurovascular supply to the arm, particularly affecting the areas innervated by the radial nerve.

Anatomy[edit | edit source]

The radial groove is situated on the posterior surface of the humerus, running obliquely from the proximal to the distal end of the bone. It is located between the medial and lateral heads of the triceps brachii muscle, which partially cover it. The groove provides a pathway for the radial nerve, one of the major nerves of the upper limb, and the deep brachial artery, ensuring their safe passage behind the humerus.

Function[edit | edit source]

The primary function of the radial groove is to protect and guide the radial nerve and the deep brachial artery along the posterior aspect of the humerus. The radial nerve is responsible for innervating the triceps brachii muscle and extending the forearm at the elbow. It also provides sensory innervation to the posterior part of the forearm and hand. The deep brachial artery, a branch of the brachial artery, supplies blood to the triceps brachii muscle and other structures in the area.

Clinical Significance[edit | edit source]

Injury to the radial nerve at the radial groove can lead to a condition known as "Saturday night palsy," where there is a loss of extension at the wrist and fingers, leading to a characteristic wrist drop. This can occur due to prolonged compression of the nerve, often as a result of falling asleep with one's arm hanging over the back of a chair. Fractures of the humerus can also damage the radial nerve at this location, potentially leading to similar deficits.