For a pinched nerve along your spine, an EMG is medically inapplicable and doesn't add anything toward a diagnosis. Evidences from a MRI and a physical exam done by a neurosurgeon will suffice. I was originally pushing for an EMG with the false belief that I need to have one in order to have a rating for my nerve damage. However, with accordance to the results from my CP exam despite not having an EMG, I will be getting at least 40% for my sciatica as an unfit condition.
Based on my experience and observation, radiculopathy will only become an unfit condition if you have a drop foot. From the military perspective, your pain, numbness, and tingling can be controlled with drugs and therefore allow you to perform your duties. With a drop foot, it's hard to justify that you can't shoot, move, and communicate effectively in full kit. Without a drop foot, you can argue radiculopathy to be an unfit condition especially if you lose coordination of your foot, forcing you to often fall and twist your ankles. Regardless, you need to see a neurosurgeon in order to have radiculopathy added as an unfit condition.
For my case, my NARSUM originally lumped my herniated disc with radiculopathy together. However, the PEB separated them and placed them as two unfit conditions.