Thumb extension is a gentle movement exercise where you take your thumb out to the side, away from your index finger, and then bring it back. You sit with your forearm resting on a table and the palm facing up, so the hand is supported and only the thumb moves. Physios often give it to get a stiff thumb moving again, for example after a thumb or wrist injury or a spell in a cast or splint.

How to do the thumb extension

Sit upright at a table and rest the forearm of the arm you are working on it, palm facing up. In the video the hand sits near the edge of the table and the other hand lies flat beside it.
Let the thumb lie relaxed alongside your index finger, with the fingers loosely straight.
Move your thumb out to the side, away from your index finger, as far as it comfortably goes. It travels level with the palm rather than lifting up toward the ceiling.
Bring the thumb slowly back to rest beside the index finger.
Keep going at a slow, even pace. Your wrist and forearm stay still on the table the whole time.

What you should feel

Light work along the back of the thumb and toward the thumb side of the wrist, with a mild stretch in the web between the thumb and index finger as the thumb opens out.

Common mistakes

Rolling the forearm or tipping the hand onto its side to make the thumb go farther.
Bending the wrist back or sideways instead of moving only the thumb.
Curling the tip of the thumb as it moves out. Keep it long and relaxed.
Flicking the thumb out fast and letting it drop back.

How often

Many programs start with 2 to 3 sets of 10 slow movements, 2 to 3 times a day. Your physio will adjust this.

Stop and check with your physio if

Sharp pain in the thumb or on the thumb side of the wrist.
Tingling or numbness spreading into your thumb and fingers. If one side of your face or body suddenly goes numb or weak, or your speech becomes slurred or muddled, call emergency services, even if it goes away.
Suddenly being unable to straighten the end of your thumb or lift it back, especially in the weeks after a wrist fracture. A thumb tendon can snap, so have a doctor check it within a few days.
Since the fracture or cast, the hand is getting more painful rather than less, the skin becomes very sensitive to light touch, or the hand changes color, temperature, swelling or sweating compared with the other one, or looks shiny. See your doctor or physio as soon as you can, within a few days at most, as this can be complex regional pain syndrome (CRPS) and early treatment may help.

From the clinic

Go only as far as the thumb moves without pain. Keep it small and smooth rather than forcing it wide. If your thumb is stiff first thing in the morning, a few gentle rounds later in the day, once the hand has warmed up, may feel easier.

The tendons that take the thumb out to the side run along the thumb side of the wrist. Ask your physio how far to go before you start if you have pain there, as with de Quervain's tenosynovitis, or arthritis at the base of the thumb. After a broken wrist, hand or forearm, or surgery on any of them such as a tendon repair, start only when your doctor, surgeon, physio or hand therapist says the bone or repair is ready for this, and follow their plan for how much to do. To work the thumb in another direction, see thumb opposition.

Written and checked by the PocketPhysio editorial team. Last updated 2026-09-28.

This page is general education, not a diagnosis or a personal treatment plan. If you have pain, an injury or a health condition, see a physiotherapist or doctor before starting new exercises.

Thumb extension