In Plain English
The brachioradialis is the large muscle running along the thumb side of the upper forearm, extending from just above the elbow toward the wrist. Although it’s classified as a forearm muscle, it plays a major role in bending the elbow, particularly when the hand is in a neutral “handshake” position. Its prominent location also makes it one of the most visible muscles of the forearm.
Technical Definition
The brachioradialis originates from the lateral supracondylar ridge of the humerus and inserts onto the distal radius near the styloid process. Unlike most elbow flexors, it inserts on the radius well above the wrist, allowing it to flex the elbow without crossing the wrist joint. It generates its greatest mechanical advantage when the forearm is in a neutral position and also assists in bringing the forearm back toward neutral from either pronation or supination.



















