Injury to R foot 6m ago. Disuse atrophy to lower leg. Muscle twitching along inner aspect of foot, now up to inside of leg to calf. Suggestions?

If the disuse. Is secondary to cast you may have nerve damage from the cast. I would recommend physical therapy. You must get that foot and leg moving. You may want to get a baseline EMG/NCV study and of course follow up with your doctor.