Plaster, Straw and Arthritis

[Simon Scott]

I'm currently working on a piece of fiction focusing on an old man who used to paint in his youth and, going back to it in his retirement, finds he has a great deal of difficulty in holding a brush with enough dexterity to produce the kind of work he would like to. I'd quite like for him to embark on sculpting in plaster and straw by the end of the piece; I've heard that this medium is quite close to sketching. I'm really just wondering how feasible it is for an artist with arthritis to work in plaster and straw. Can anyone here with experience of either or both enlighten me?

Many thanks in advance,

SHS.