Final answer:
The flexor carpi radialis and extensor carpi radialis brevis are the agonist and antagonist muscles respectively, involved in wrist radius deviation. They facilitate the movement and stability of the wrist, with consequences on their function should a fracture affect the adjacent radiocarpal joint.
Step-by-step explanation:
Agonist and Antagonist Wrist Radius Deviation
The muscles involved in wrist radius deviation include both agonists and antagonists. An agonist muscle is one that creates a certain movement. In this context, the flexor carpi radialis is an agonist that flexes and abducts the hand at the wrist, decreasing the angle at the joint. It targets the superficial anterior compartment of the forearm, thus bending the wrist toward the body and tilting the hand to the side away from the body.
On the opposite side, the extensor carpi radialis brevis is an antagonist muscle to the flexor carpi radialis, as it performs the opposite function by extending and abducting the hand at the wrist, thus increasing the angle at the joint. The extensor carpi radialis brevis is located in the superficial posterior compartment of the forearm, straightening the wrist away from the body while tilting the hand to the side away from the body.
Both these muscles assist the extensor radialis longus in extending and abducting the wrist and also play a role in stabilizing the hand during finger flexion. Understanding their function is important in assessing wrist injuries such as fractures of the distal radius. For instance, if the distal radius fracture involves the joint surface of the radiocarpal joint, it could lead to impaired movement and stability of the wrist, affecting both agonist and antagonist muscles.