Multiple Sclerosis? Can This Be a Sports Injury?

Hello all
I am writing because I am at my wits end, and don’t know where else to look. My husband was working out on a leg press machine 3 years ago. He did many reps and then felt a pop on his lower back. He felt a little bit of pain but was otherwise ok, but after he got up in the next couple of days he was wobbly and could not balance. He went to the dr. and all they have done is test after test after to prove that what he has is multiple sclerosis, but all test for that have come back negative.

He has had around 8 MRIs, a cat scan, sonogram and x-rays, but nothing comes up as a direct problem with this back. We are going on 3 years and he still can’t walk properly. My questions are has anyone experienced something like this ? He has seen 11 neurologist who only look to prove if he has MS. Should he see a different type of dr. maybe someone who practices sports medicine ?

Also, we have been telling everyone how this happened and they tell us that it’s a coincidence that he can’t walk after using the machine, that his problem must be somewhere else but they don’t know where that somewhere else is. Any help/feedback would be greatly appreciated. Thank you

Any pain right now? Or is it just weakness/loss of musclecontroll that gives him problem walking?