Muscle Anatomy

extensor carpi ulnaris

The Extensor Carpi Radialis Ulnaris (ECRU) muscle is situated in the forearm, contributing to the musculature of the lateral aspect. It possesses a moderate size and elongated structure, playing a significant role in forearm function.

Originating from the lateral epicondyle of the humerus, the ECRU takes its starting point from the bony prominence on the outer side of the elbow joint. This anatomical origin provides the foundation for the muscle's extension along the forearm.

The ECRU inserts at the base of the fifth metacarpal bone and extends to the dorsal surface of the pisiform and the tendon of the flexor carpi ulnaris. This insertion arrangement establishes a critical connection with the wrist and hand, influencing wrist extension and abduction.

Functionally, the ECRU serves as a wrist extensor and abductor. Contraction of the muscle results in the extension of the wrist joint and contributes to the abduction movement. Additionally, the ECRU plays a role in stabilizing the wrist during activities involving gripping and lateral hand movements. Its anatomical location and functional contributions make the ECRU an essential component of the forearm musculature, facilitating a range of movements necessary for daily tasks.