Brachioradialis is a muscle located in the forearm, that acts to flex the elbow.
Attached to the distal radius and the lateral epicondyle of the humerus, its body can be made visible in certain types of flexion.
If a person half-pronates their arm, to make a fist like they're holding a handled vessel of beer, then puts their fist under a table or desk and tries to flex at the elbow, the brachioradialis will stand out of the forearm, visible under the skin.
It is on the dorsal side of the forearm, so is innervated by the radial nerve.
Where muscles are connected with its skin, they lie as a flattened layer beneath it, and are connected with its areolar tissue by larger or smaller bundles of fibers, as in the muscles of the face.
In some muscles, which otherwise would belong to the quadrilateral or triangular type, the origin and insertion are not in the same plane, but the plane of the line of origin intersects that of the line of insertion; such is the case in the Pectineus.
In a muscle with parallel or nearly parallel fibers which have the same direction as the tendon this corresponds to the anatomical cross-section, but in unipinnate and bipinnate muscles the physiological cross-section may be nearly at right angles to the anatomical cross-section as shown in Fig.