If you are recuperating from a sport injury or perhaps something more health oriented (carpal tunnel, arthritis, stroke, etc.) and want some more fine dexterity skills, you should try FingerWeights!
Just like you have free weights for the larger muscle groups. FingerWeights are a products specifically for your fingers. They come in several weights and you progress from one group to the next. They slip on your digits and are easy to use.
They come in a little pouch, so you or your physical therapist can easily bring them wherever you like!