Thumb flexion and extension takes your thumb through its full range: first across the palm toward the base of your little finger, then back and out wide to the side, away from the index finger. You sit with the back of your hand resting on a table, palm up, so only the thumb moves while the fingers stay relaxed. No band or weight is used. Physios often give it to get a stiff thumb moving again, for example after a hand or wrist injury or a spell in a cast or splint.

How to do the thumb flexion and extension

Sit at a table and rest the forearm of the arm you are working on the tabletop, palm facing up, with the hand near the edge. Rest your other hand flat on the table, as in the video.
Let the fingers of the working hand stay relaxed and slightly curled. They do not move during the exercise.
Slowly bend the thumb across your palm, aiming the tip toward the base of your little finger or ring finger, as far as it goes comfortably. Pause for a moment.
Bring the thumb back across the palm and take it out wide to the side, away from the index finger, as far as it comfortably goes. Pause again.
Keep moving between the two positions at a slow, even pace, with the wrist and forearm resting still on the table.

What you should feel

A gentle pull through the thumb joints as they bend, and light work along the back of the thumb and the thumb side of the wrist as it opens out. A stiff thumb may not reach very far either way at first.

Common mistakes

Curling the fingers into a fist as the thumb bends across.
Turning the forearm or lifting the wrist off the table to make the thumb go farther.
Forcing the thumb past the point where it stops moving easily.
Flicking the thumb quickly from one side to the other instead of moving slowly.

How often

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

Stop and check with your physio if

Sharp pain in any thumb joint or on the thumb side of the wrist.
The thumb catches or clicks painfully as it bends, or gets stuck bent across the palm.
Tingling or numbness in the thumb or 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

The voice guide for this exercise describes a small elastic band looped around the thumb and each finger in turn. The video shows no band. The thumb moves on its own, across the palm and back out to the side, and that is what the steps describe. For the banded version, which works the muscles that open the whole hand, see finger extension with a rubber band.

Keep each movement pain free, and let the range come back bit by bit over the following days. To work one direction on its own, thumb flexion bends the thumb across the palm and thumb extension takes it out to the side.

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. If you have pain on the thumb side of the wrist, as with de Quervain's tenosynovitis, or arthritis at the base of the thumb, ask your physio how far to go before you start. A thumb that catches or clicks as it bends can be a sign of trigger thumb, so mention it to your physio or doctor.

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 flexion and extension