Anconeus

Origin and insertion (Structure)

The anatomical structure of the anconeus muscle is characterized by the following attachment points:

• Origin (Origo): muscle fibers originate from the posterior surface of the lateral epicondyle of the humerus (epicondylus lateralis). An additional attachment point is the radial collateral ligament (lig. collaterale radiale).
• Insertion (Insertio): the muscle runs inferiorly, attaching to the posterolateral surface of the ulna (ulna). The insertion site is located at the base of the olecranon (olecranon).

What is the function of the anconeus muscle?

In the biomechanics of the upper limb, the m. anconeus performs two main tasks:

• Forearm extension: the muscle participates in extending the arm at the elbow joint. In this movement, it acts as a weak synergist to the triceps brachii muscle (m. triceps brachii).
• Capsule tension: the anconeus muscle tenses the capsule of the elbow joint.

According to classification, the anconeus muscle belongs to the posterior compartment of the arm (extensors). This group also includes the triceps brachii muscle and the articularis cubiti muscle (m. articularis cubiti).

Blood supply and innervation

• Blood supply: the blood supply to the muscle is provided by the recurrent interosseous artery — a. interossea recurrens. This artery is a branch of the posterior interosseous artery (a. interossea posterior). Additional blood supply comes from branches of collateral arteries.
• Innervation: the muscle is innervated by the radial nerve — n. radialis. In the myology section, spinal segments C7–C8 are indicated for the anconeus muscle.

Topography and syntopy of the elbow joint

The anconeus muscle belongs to the structures of the posterior elbow region:

• Relation to the joint capsule: posteriorly, the capsule of the elbow joint is covered unevenly. The upper part is covered by the tendon of the triceps brachii muscle, and the inferolateral part by the anconeus muscle (m. anconeus). Medially, the capsule is not protected by muscles; it is covered only by the deep fascia and skin.
• Adjacent structures: in dissections of the posterior elbow region, the muscle is visualized near the posterior border of the ulna (margo posterior ulnae), arm fascia (fascia brachii), and subcutaneous olecranon bursa (bursa subcutanea olecrani). The posterior antebrachial cutaneous nerve (n. cutaneus antebrachii posterior) is also marked in this area.
• On transverse section: at the level of the elbow joint, the m. anconeus is identified along with the tendon of the triceps brachii muscle, olecranon, lateral epicondyle, extensor carpi radialis longus muscle (m. extensor carpi radialis longus), and brachioradialis muscle (m. brachioradialis).
• Layers of the forearm: on anatomical diagrams of forearm muscles, the anconeus muscle is visualized in the superficial and deep layers of the posterior region.

Class and exam questions

What else to study on this topic

• Triceps brachii muscle (m. triceps brachii)
• Radial nerve (n. radialis)
• Topography of the elbow joint
• Posterior arterial network of the elbow joint (rete articulare cubiti)

Other topics in the "Anatomical Structures" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.