The opponens pollicis muscle contributes to pain in the lower thumb and wrist.
The adductor pollicis muscle contributes to pain in the thumb and thumb pad.
The lumbrical muscles of the hand contribute to pain in the back of the hand and the fingers. Pain in the index finger and the little finger are the most common. Stiffness in the finger joints mimics arthritis pain. Stiffness and pain when opening and closing the hand is also common.
The extensor digitorum is located in the back of the forearm. It contributes to pain in the back of the hand and middle finger which sometimes radiates up into the back of the wrist and the back of the forearm. Pain is occasionally felt in the front of the wrist, just below the palm.
The extensor carpi radialis brevis muscle is located in the back of the forearm on the side of the thumb. It contributes to a burning pain in the back of the hand that sometimes extends up to the forearm. Twisting the wrist can cause excruciating pain. It also can cause a weakened unreliable grip.
The extensor carpi radialis longus contributes to pain in the elbow, forearm, back of the hand and first finger. It contributes to tennis elbow and can cause a weak unreliable grip.
The brachioradialis is located on the outside of the arm and is a contributor to tennis elbow. It can cause pain on the outside of the elbow, forearm and often descends down into the wrist and thumb. It can contribute to numbness around the thumb as well as a weakened grip.