The carpometacarpal—or CMC—joint sits at the base of the thumb near the wrist. Its mobility allows the thumb to rotate and oppose the fingers, making pinching and grasping possible. That same mobility also places significant demands on the joint.
In thumb CMC osteoarthritis, the cartilage within the joint wears down over time. Symptoms vary: some people have changes on an X-ray with little pain, while others experience substantial discomfort during daily tasks.
Common signs
- Pain or tenderness at the base of the thumb.
- Pain with pinching, gripping, turning keys, opening containers, or prolonged hand use.
- Weakness or a sense that objects are harder to hold.
- Swelling, stiffness, reduced motion, or a visible bump near the joint.
- Aching after activity or at night.
The goal is not to stop using your thumb. It is to reduce unnecessary joint stress while maintaining useful motion, strength, and participation in the activities you value.
How conservative management can help
Many people begin with nonsurgical care. The right combination depends on symptom severity, medical history, activity demands, and the condition of the joint.
Orthoses and support
A thumb-support orthosis can reduce painful movement and improve stability during selected activities or at rest. Some people do well with a prefabricated support; others benefit from a custom orthosis shaped to their hand. More support is not always better—the goal is the least restrictive option that helps.
Joint protection and task modification
Small changes can decrease the force passing through the thumb. Examples include using larger handles, opening containers with assistive tools, carrying objects with two hands, sliding rather than lifting when practical, and using the palm or whole hand instead of a sustained pinch.
Purposeful exercise
Gentle mobility and strengthening may support joint mechanics and hand function. Exercises should match the individual; repeatedly pushing through sharp pain or using generic strengthening tools can aggravate symptoms. A hand therapist can identify which muscles and movement patterns need attention.
Symptom management and medical options
Heat or cold may feel helpful depending on the person and situation. Medication and injections are medical decisions that should be discussed with an appropriate clinician, particularly when other health conditions or medications are involved. Surgery may be considered when symptoms remain significantly limiting despite appropriate conservative care.
What hand therapy adds
A hand therapist looks beyond the painful joint to understand when symptoms occur and which tasks matter most. Treatment may include a custom orthosis, education, targeted exercise, modification of tools and techniques, and a plan for balancing protection with continued use.
Because therapy can take place in your home, we can work with the actual objects and routines causing difficulty—from kitchen tools and gardening equipment to a musical instrument or work setup.
When to get evaluated
Seek an evaluation when thumb pain persists, is worsening, interferes with sleep or daily function, or follows an injury. Sudden severe pain, marked swelling, deformity, loss of sensation, discoloration, or an open wound warrants prompt medical attention.