This is assisted by elbow flexors (brachialis, brachioradialis, biceps brachii) which bring the humerus to the forearm.
The tendon of the brachioradialis attaches at its base, and the radial collateral ligament of the wrist attaches at its apex.
When pronated, the brachioradialis is more active during elbow flexion since the biceps brachii is in a mechanical disadvantage.
It crosses brachioradialis to enter posterior of forearm near the back of the wrist and supply dorsum of hand.
It will also allow the transfer of the other muscles crossing the elbow joint (like the m. brachioradialis and m. extensor carpi radialis longus).
When the forearm is pronated, the brachioradialis tends to supinate as it flexes.
Turning the palms inward transfers load from the biceps to the brachioradialis.
One of the three muscles of the radial forearm group, it initially lies beside the brachioradialis, but becomes mostly tendon early on.
