|Origin||Humeral head: Medial epicondyle of humerus via common flexor tendon|
Ulnar head: Olecranon and upper 2/3 of posterior border of ulna
Base of fifth metacarpal bone
|Action||Flexes hand at wrist joint|
Adduction of hand at wrist joint
Very weak flexion of the elbow joint
|Nerve||Ulnar nerve (C7,C8, T1)|
Ulnar recurrent artery
Location & Overview
The flexor carpi ulnaris muscle is the most powerful wrist flexor. It has two heads, a humeral head and an ulnar head, which are linked by a tendinous arch. It is located in the anterior compartment of the forearm. It is one of the superficial flexor muscles of the forearm and the most medial of these superficial flexor muscles. The other superficial forearm flexors are: the palmaris longus, pronator teres, flexor carpi radialis, and the flexor digitorum superficialis .
The flexor carpi ulnaris muscle plays an important role in various activities. For instance, it is helpful in weightlifting exercises that involve wrist flexion and adduction. In racquet sports such as tennis or badminton, the flexor carpi ulnaris stabilises the wrist during hitting and provides the required force for wrist flexion and adduction during the swing. Similarly, in golf, it assists with generating the necessary force for wrist flexion and adduction during the swing, particularly in the follow-through. The flexor carpi ulnaris muscle also assists in everyday activities such as typing, writing by hand, and DIY home improvements by aiding in stabilising and holding tools like hammers and saws.
Origin & Insertion
The flexor carpi ulnaris muscle has two heads, a humeral head and an ulnar head. These two heads arise at the origin points of this muscle. The humeral head originates from the common flexor tendon, on the medial epicondyle of the humerus. The ulnar head originates from the olecranon and the upper two thirds of the posterior border of the ulna. The two heads converge via a tendonous arch. The muscle then continues down the forearm crossing the wrist joint to insert onto the fifth metacarpal bone, the hook of hamate, and the pisiform bone of the wrist. The flexor carpi ulnaris inserts into the hook of hamate through the pisohamate ligament and inserts into the fifth metacarpal bone through the pisometacarpal ligament  .
The actions of the flexor carpi ulnaris are flexion and adduction of the hand at the wrist joint (radiocarpal joint). In addition to flexion and adduction, the flexor carpi ulnaris can also flex the elbow joint. However, it is very weak when it comes to elbow flexion and this is by no means a main action of the flexor carpi ulnaris  .
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Flexor Carpi Ulnaris Flashcards
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|↑9, ↑10||Sharpe F, Barry P, Lin SD, Stevanovic M. Anatomic study of the flexor carpi ulnaris muscle and its application to soft tissue coverage of the elbow with clinical correlation. J Shoulder Elbow Surg. 2014 Jan;23(1):82-90. doi: 10.1016/j.jse.2013.07.057. PMID: 24331124.|
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