Patients with neck pain and discomfort may complain of pain in the thumb region with difficulties in moving the painful thumb in abduction.
Pain at the base of the thumb can be felt in cases of pain and spasm in the muscles that arise or attach or cross over the region of the wrist bone of the thumb and knuckle bone of the thumb known as the carpometacarpal phalangeal joint.
Thumb abduction consists of moving the thumb in a 90° angle away from the plane of the palm with the palm facing upward.
The muscles involve in thumb abduction consists of:
- abductor pollicis brevis supplied by the median nerve (C8, T1)
- flexor pollicis brevis, superficial head supplied by the median nerve and deep head supplied by the ulnar nerve (C8 and T1)
- abductor pollicis longus supplied by the radial nerve (C7, C8)
- opponens pollicis supplied by the median nerve (C8, T1)