We use EMG all the time to diagnose nerve and muscle disorders.
Some Physiatrists do none, most do some, some do a lot.
We use electrical stimulation to study motor and sensory nerves for how fast they conduct and how large the responses are to gauge nerve damage.
We use a needle to test the stability of the electrical membrane of muscles to determine primary muscle problems like myopathies, or secondary issues due to neuropathies?
http://www.aanem.org/Education/Patient-Resources/Learn-About-an-EMG.aspx
Is that the kind of information you are looking for?