Use EMG to help find causes of back pain

How to use EMG to help find causes of back pain Electromyography (EMG) detects the electrical potential generated by muscle cells, and can test nerve function. EMG can help physiatrists pin down the cause of back pain in cases such as spinal stenosis -- a narrowing of the spinal column -- in which the diagnosis can be tricky just relying on imaging techniques such as MRI.