Support the hand on its side
Sit beside a stable table and support the forearm. Let the hand rest on its little finger edge with the palm facing sideways, rather than flat on the table. Keep the fingers relaxed and the wrist comfortably aligned with the forearm. The Bexley active thumb guide uses this supported side position. Do not press through the hand or force it into a rigid shape.
Open a small empty cup space
Start with the thumb near the index finger. Move it away from the palm using its own movement, as though making room to take a cup. The Cambridge hand therapy guide describes that cue for palmar abduction. With the palm upright, the thumb opens out of the palm plane, roughly parallel to the table. It does not simply slide upward along the palm plane. Use a small comfortable path; no cup needs to be held.
Return without squeezing
Bring the thumb back toward the index finger slowly and let the hand relax. Do not pinch the finger or snap the gap shut. The thumb tip joints can remain relaxed instead of being forced straight. Try another comfortable movement only if control stays clear. There is no required L shape, maximum angle or universal repetition count.
Keep the wrist out of the task
Watch whether the forearm rolls, the wrist bends or the whole hand slides to create the gap. Reduce the movement and reset the support if that happens. Do not use the other hand to pull the thumb or add a band or putty. Those change an active movement task into a different exercise.
Respect personal restrictions
Stop for pain, locking, new swelling, numbness or loss of control. Follow individual guidance after injury, surgery or a splint, and seek qualified advice for persistent symptoms. These source leaflets describe hand therapy; their holds and schedules are not general prescriptions. This guide does not diagnose or treat a thumb condition. The beginner mobility guide helps organize a permitted comfortable practice.
Choose a distinct next movement
Thumb opposition takes the thumb toward fingertips, while finger spreading on a table separates the fingers along the surface. Keep those tasks distinct from opening the thumb out of the palm plane. If making a note, record side, support, comfort and whether the wrist stayed quiet. A larger gap is not proof of lasting improvement. Article translations do not mean the Mobility app supports every article language.
If you want to understand movement along the palm plane instead, the flat palm thumb slide explains table support and the source requirement for professional advice.