@swalton1969, It's understandable that you are disgusted with not getting a diagnosis and being able to move on with a treatment. You didn't mention having any pain in the leg which I think would be a symptom if you had a pinched S1 nerve. Might be a talking point you can have with your neurologist.

"In conclusion, muscular hypertrophy has a myopathic cause and a neurogenic cause. To discriminate between these, a proper neurologic examination and laboratory tests such as muscle enzyme test, EMG, MRI, and muscle biopsy are needed. Neurogenic muscle hypertrophy is very rare, but we recommend clinicians consider this problem when patients complain of lower limb hypertrophy and pain."
--- Neurogenic muscle hypertrophy: a case report: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5061645/

Is pain also a symptom?