Pronator teres
Musculus pronator teres
The most lateral superficial forearm flexor. It runs obliquely from the medial epicondyle and coronoid process to the middle of the radius, pronates the forearm and assists elbow flexion.
Overview
Pronator teres has a large humeral head from the medial epicondyle (common flexor origin) and medial supracondylar ridge, and a small ulnar head from the coronoid process. The median nerve passes between its two heads, and the ulnar artery passes deep to it. The muscle crosses the forearm obliquely to the pronator tuberosity at the middle of the lateral surface of the radius, the highest point on the curve of the radius. It forms the medial border of the cubital fossa. It works with pronator quadratus to pronate and becomes more active in rapid or resisted pronation. It also weakly flexes the elbow.
Anatomy
- Origin
Humeral head: medial epicondyle (common flexor origin) and the medial supracondylar ridge. Ulnar head: coronoid process of the ulna.
- Insertion
Middle of the lateral surface of the radius (pronator tuberosity).
- Action
Pronation of the forearm; flexion of the elbow.
- Innervation
Median nerve.
- Nerve roots
C6–C7
- Arterial supply
Anterior ulnar recurrent artery; radial and ulnar arteries.
- Relations
The median nerve passes between its two heads. It forms the medial border of the cubital fossa, and brachioradialis forms the lateral border.
Function
- Pronates the forearm
- Assists elbow flexion
Clinical significance
Pronator syndrome
The median nerve is compressed between the heads of pronator teres, often in people doing repetitive pronation. This causes aching in the forearm and paraesthesia in the median distribution including the palm (palmar cutaneous branch), which distinguishes it from carpal tunnel syndrome.
Compiled from standard anatomy and physiology references — see the Muscular System sources. For education only; not medical advice.