Rehabbing your arm
Your arm's activation will probably start with your bicep, spasticity will kick up in your elbow.
Early Exercises
Try this exercise along with Estimming you arm as pictured.
During this exercise, place stim pads on your arm as shown in the below pic
prevent arm curling
Because your bicep will activate before your tricep, you will likely struggle with arm curling. You can buy braces that will keep your arm straight, or do tricp exercises
We recommend the Alon Twig for an arm brace.Putting on the Alon Twig:
Build Strength
Build strength with pushups and planks. If your fingers keep curling in in a way that prevents you from holding a plank, try wearing a Golden Gate Brace while you do your exercises.
Putting on a Golden Gate Brace: