The muscles that act on the elbow joint are primarily responsible for flexion, extension, supination, and pronation of the forearm.
Key Elbow Muscles
Here's a detailed breakdown of the muscles involved in elbow movement, incorporating information from the reference:
Muscles Innervated by the Radial Nerve
According to the reference, the radial nerve innervates several key muscles that affect the elbow joint:
- Brachialis (lateral portion): Primarily a flexor of the elbow joint. Notably, only its lateral part is innervated by the radial nerve.
- Anconeus: Assists in elbow extension.
- Supinator: Responsible for forearm supination (turning the palm upwards).
- Brachioradialis: Contributes to elbow flexion and pronation to mid-position.
- Triceps brachii: The main extensor of the elbow.
Table Summary of Elbow Muscles Innervated by the Radial Nerve
Muscle | Primary Function(s) | Nerve |
---|---|---|
Brachialis | Elbow flexion (lateral portion) | Radial |
Anconeus | Elbow extension | Radial |
Supinator | Forearm supination | Radial |
Brachioradialis | Elbow flexion, pronation to mid-position | Radial |
Triceps brachii | Elbow extension | Radial |
Other Important Elbow Muscles
While the reference focuses on radial nerve innervation, several other muscles play a role at the elbow:
- Biceps brachii: A powerful flexor of the elbow and a supinator of the forearm. While it also works on the shoulder joint, it is a key muscle in elbow function.
- Pronator teres: Responsible for pronation of the forearm (turning the palm downwards) and also assists with elbow flexion.
Practical Insights
- The brachialis is a powerful elbow flexor, and it’s unique in that it acts on the elbow regardless of pronation or supination of the forearm.
- The triceps brachii is the only muscle on the posterior side of the humerus responsible for extension at the elbow joint.
- The biceps is a powerful elbow flexor but its strength is significantly reduced when the arm is pronated.
- Elbow health relies on balanced strength and flexibility across all these muscle groups.
Understanding the specific muscles around the elbow joint, along with the nerves that control them, can help in various aspects of fitness, rehabilitation and in the assessment of neurological deficits.