Resisted thumb radial adduction (flexion) - palm down (Thumb radial adduction (flexion) strengthening, with band, palm down)

Sit upright in a chair.
Place your affected arm on a table, with your palm face down and your thumb resting away from your hand.
Use your opposite hand to wrap the band once around the base of your thumb, holding the end taut.
Keeping the band still with your opposite hand, move your thumb in towards your index finger without bending the tip.
Control the movement against the pull of the band as you move your thumb back to the start position.