Brad G. answered 07/01/19
Sign Language, Guitar, or Basketball Tutor
Great questions. There are some generally accepted signs that have English roots. There are debates in the community about using certain signs that have those root english elements. To delve more into the subject the term disability is a sensitive subject in the deaf community because it focuses on what they cant do compared to what they can do.
I have seen D/A as a widely used term. I have also seen a similar sign where D/A is touching the crux of the thumb and index finger of the opposite hand.
You can also spell disability and then sign D/A to establish that you will use that for the remainder of that communication.
Concussion is described as a verb. So use classifiers to show how the concussion occurred. If it is the subject or noun to be discussed. I could spell it every time or expand the meaning of concussion and sign that. For example: Sign "Brain Injury" similar to Brain Hurt with the classifier of a fist upright whipping back to forward.