Hello,
As your daughter has a fall from the staircase, the usual mechanism of the
injury will be an outstretched hand.
During this she may have injured the ligament and some bony structures excessive movement.
First thing is to use the hand brace to stabilize the carpal bones is advised as the scaphoid is the usual one which may get trouble.
Doing hot water fermentation will help reduce the swelling, pain and create a soothing effect in the muscle.
Post a week or so you can try doing simple thumb movements within the water and then achieve the Range of motion of the thumb within the pain limits in all possible movements.
Using a small rubber band will be good to strengthen the hand muscles to improve the outcome score.
If you find it difficult then a physiotherapist help can be taken to learn the movements.
Hope I have answered your query. Let me know if I can assist you further.
Take care
Regards,
Jay Indravadan Patel, Physical Therapist or Physiotherapist