I'm On Week 5 Post Op Of Akin Bunion Surgery.

I'm on week 5 post op of akin bunion surgery. Dr has removed bandages and I have to wear just a foam wedge on mid foot area and big toe. He told me I can wear sneakers but I can't fit into them because of the foam wedge. Also noticed weakness in my calf. I wore a cam Walker for first 5 weeks and I dont feel secure without it because of the calf weakness. Is there exercises I can do to strengthen my calf muscles?