I’m sorry to see what your husband is experiencing. He’s so young to have such a disabling condition. Was his EMG normal?

I’ll just add that I encountered something similar when I was in my 40’s. I was very active and ran, I suddenly got extremely sore, weak and stiff leg muscles. I posted a long post about it somewhere around here. It’s difficult to explain how sore, weak and stiff my legs were. I could barely function. Multiple tests were not helpful in bringing a diagnosis. I saw primary, neurologist, endocrinologist, orthopedist, and rheumatologist. The rheumatologist wrote my primary a letter saying that it appeared to be polymyalgia rheumatica, except I was too young. I’ve always wondered what it really was. It lasted about 6 months and gradually improved. My legs were not normal for at least a year. If I got it again, I’d work with a therapist to get the stiffness out.

Best of luck with everything. I hope he can find answers and sone treatment that helps.