The Extensor Carpi Radialis Brevis arises from the lateral epicondyle of the humerus, by the common extensor tendon; from the radial collateral ligament of the elbow-joint; from a strong aponeurosis which covers its surface; and from the intermuscular septa between it and the adjacent muscles. Wiki
Posterior base of the 3rd metacarpal.
The fibres end approximately at the middle of the forearm in the form of a flat tendon, which is closely connected with that of the extensor carpi radialis longus, and accompanies it to the wrist; it passes beneath the abductor pollicis longus and extensor pollicis brevis, beneath the extensor retinaculum, and inserts into the lateral dorsal surface of the base of the third metacarpal bone, with a few fibres inserting into the medial dorsal surface of the second metacarpal bone. Wiki
Extends the hand at the wrist.
It is an extensor, and an abductor of the hand at the wrist joint. That is, it serves to manipulate the wrist so that the hand moves away from the palm and towards the thumb. The muscle, like all extensors of the forearm, can be strengthened by exercise that resist its extension. A wrist roller can be used and reverse wrist curls with dumbbells can be performed. Wiki
Innervation – Nerve control
Deep branch of the radial nerve.
The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin. Wiki
The radial artery arises from the bifurcation of the brachial artery in the cubital fossa. It runs distally on the anterior part of the forearm. Wiki
Flexor carpi ulnaris muscle.
The flexor carpi ulnaris muscle (also known as the FCU) is a muscle of the human forearm that acts to flex and adduct the hand.
Pictures of muscles
Trigger Point Referrals