Osteoarthritis at the base of the thumb is a common overuse or old-age pathology (DeLisa et al., 2005). The joint at the base of the thumb which allows for the swivel and pivoting motions is referred to as the CMC (carpometacarpal) joint.
Main movements of the thumb are: flexion (moving it towards the palm), extension (“hitch a lift” position), abduction (takes the thumb away from the palm in a right angle), adduction (pulls the thumb to the palm) and opposition (unique movement that enables the thumb to touch each finger) (McMillan and Carin-Levy, 2012).
Osteoarthritis of the CMC joint causes damage and swelling (inflammation) making it painful to grip and move the thumb. Because of its design, it tends to wear out and develop arthritis early in life.
When pain and disability of the fingers and hands cause severe pain and problems in a patient’s daily life, physiotherapy focuses on grip and movement modification so over use can be avoided. There are no cures for osteoarthritis however Physiotherapy, splinting, strengthening and medication can assist in managing symptoms.
DeLisa J.A. et al., Physical Medicine and Rehabilitation: Principles and Practice, Volume 1, Lippincott Williams & Wilkins, Philadelphia, PA, p: 775
McMillan I. and Carin-Levy G., 2012, Muscles, Nerves and Movement in Human Occupation, Wiley-Blackwell, Oxford, UL, p: 143