The bicipital aponeurosis is a flat, tendinous band extending from the biceps brachii tendon in the elbow region. It is not typically referred to as the "brachial aponeurosis". It is also not an aponeurosis of the brachialis muscle. If someone is referring to a brachial aponeurosis, they are likely incorrectly referring to the bicipital aponeurosis.
Bicipital Aponeurosis Explained
The bicipital aponeurosis, also known as the lacertus fibrosus, serves as a crucial component in the structure and function of the elbow and forearm.
- Origin: It originates from the distal biceps brachii tendon, specifically on the medial side.
- Course: It extends inferomedially across the cubital fossa (the triangular area on the anterior elbow).
- Insertion: It blends with the antebrachial fascia, the deep connective tissue covering the muscles of the forearm.
Function
The bicipital aponeurosis plays several important roles:
- Protection: It protects the underlying brachial artery and median nerve as they pass through the cubital fossa.
- Tension Distribution: It helps distribute tension from the biceps muscle to the forearm fascia, increasing the efficiency of forearm supination (rotating the palm upwards).
- Venous Return: Some sources suggest that contraction of the biceps, via the aponeurosis to the deep fascia, assists in venous return.
Clinical Significance
Injuries to the bicipital aponeurosis are relatively uncommon, but can occur with forceful hyperextension of the elbow. Diagnosis is often clinical, with pain and tenderness in the cubital fossa. Conservative treatment is usually sufficient.
