In short, Yes. Sign Language by its very nature forces users to improve their coordination and dexterity. That aside there are exercises that you can do to help to improve coordination and dexterity. Here is an older video of me explaining Stab and Say in ASL. https://www.youtube.com/watch?v=gnSrJgvJSR8 . There are more exercises that can be done.
Helping kids with dexterity?
2 Answers By Expert Tutors

Gwen T. answered 07/03/19
Sign Language Tutor
I am so sorry it took someone so long to answer this question. I worked in the special education department in a high school with an individual who had Downs, cognitive disabilities, severe Autism, and was hard of hearing. Sign was also their primary language. Message me and I'd love to talk to you about my thoughts and how I helped them. I feel like this is a more personal question that would be able to be addressed more in depth privately.
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