Hi Spike, I'm glad they have checked your gait. Muscle wasting is an unfortunate aftereffect of injuries in early life.
I have a friend here who has that issue after a long-ago broken ankle. He now wears an ankle brace and uses a cane for stability. I know we never want to admit it might be necessary, but...perhaps better than broken bones.
Another question to ask the physio is whether nerve/muscle stimulation might "wake things up." It's great that you are persisting - nobody wants to watch life from the sidelines.
Sue