Common Flexor Origin Tendon

tendo communis musculi flexorum

The common flexor origin is the conjoined tendinous attachment of the wrist and finger flexors to the medial epicondyle: pronator teres (most superior), flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and flexor digitorum superficialis (deepest). The pronator teres is the largest and most proximal contributor. The UCL and the origin of the flexor-pronator mass share the medial epicondyle, making them codependent in medial elbow stability.

Region: Forearm

Clinical Relevance

Clinical Notes

Common flexor origin tendinopathy (medial epicondylitis, golfer's elbow) involves intratendinous degeneration at the pronator teres and FCR origins at the medial epicondyle, producing medial elbow pain reproduced by resisted wrist flexion and pronation. It is less common than lateral epicondylitis. UCL insufficiency in throwing athletes produces secondary common flexor origin stress from valgus overload, and distinguishing isolated tendinopathy from UCL-mediated medial pain requires dynamic valgus stress testing and MRI. Surgical medial epicondyle release must preserve the UCL anterior band deep to the flexor-pronator mass.

Pathology

Common Injuries & Conditions

Common Flexor Origin Tendinopathy in Golfer's Elbow

Angiofibroblastic degeneration of the pronator teres and FCR at the medial epicondyle produces medial elbow pain reproduced by resisted wrist flexion; UCL insufficiency must be excluded by valgus stress testing and MRI arthrogram before attributing symptoms solely to the common flexor origin, as combined medial elbow pathology requires different management.