Understanding CMC Arthritis and How Occupational Therapy Can Help

Carpometacarpal (CMC) arthritis, commonly known as thumb arthritis, is a condition that affects the base of the thumb, causing pain and limiting hand function. This blog will explore the causes, symptoms, and how occupational therapy can help manage CMC arthritis effectively.

What is CMC Arthritis?

CMC arthritis occurs at the carpometacarpal joint, where the thumb meets the wrist. This joint allows for a wide range of thumb movements that you make every day.  In CMC arthritis, the cartilage that cushions the bones in this joint wears away, leading to bone-on-bone contact. This friction is what causes pain and inflammation in the hand.

Causes and Risk Factors

Several factors can contribute to the development of CMC arthritis. As we age, our bodies start to break down from repeated wear and tear. This condition is most common in people over 40 due to the natural repetitive movement of the joint. Genetics can also be a risk factor for those that are predisposed to arthritic conditions.

Like other forms of arthritis, previous injury can lead to CMC arthritis. Trauma or breaks in the joint lead to additional deterioration. And because we use our thumbs so frequently throughout the day, the continuous stress on the thumb joint can contribute to the development of arthritis.


The symptoms of CMC arthritis can vary in severity based on use and time with the condition. Some of the common symptoms include pain at the base of the thumb, swelling and inflammation around the joint, stiffness, weakness and reduced range of motion in the thumb and in severe cases, thumb deformity.

Occupational Therapy

Whether or not you have surgery to treat the condition, occupational therapy plays a crucial role in managing CMC arthritis. Here are some key strategies used in occupational therapy:

  • Splinting: Custom splints can provide support to the thumb joint, reduce pain, and prevent further deformity. Splints can be worn during specific activities or continuously, depending on the severity of the condition.
  • Heat and Cold Therapy: Applying heat can help relax muscles and improve circulation, while cold packs can reduce inflammation and numb the pain.
  • Activity Modification: Teaching patients how to modify their activities to reduce stress on the thumb joint is essential. This includes using adaptive equipment or altering techniques for tasks like opening jars or turning keys. Educating patients on ergonomic principles can also help them set up their workstations and home environments to minimize strain on the thumb.
  • Thumb Exercises: Specific exercises can help maintain or improve the strength and flexibility of the thumb. Comprehensive hand therapy programs tailored to individual needs can significantly enhance function and reduce symptoms.

CMC arthritis can be a debilitating condition, but with the right management strategies, individuals can lead fulfilling lives and continue to engage in their desired activities. Occupational therapy focuses on pain relief, joint protection, strengthening, and patient education. If you or someone you know is struggling with thumb arthritis, contact Motus to make a significant difference in managing this condition and improve quality of life.

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