Radial nerve palsy: What Investigations to be done?

In a case of radial nerve palsy, a thorough clinical examination is most important! But there are some features that may not be very obvious on clinical examination. For instance, the nature of the injury - whether the injury is a neuropraxia and hence transient, or a complete cut of the nerve which will not recover on its own!
Hence it is prudent to order appropriate investigations. But when the patient gets back with the report, we need to understand the findings to be able to interpret it on our own also, as we will want to know certain things that may not have been provided in the printed report.
This video talks about the basic investigations to order, like the X-rays, Ultrasound, MRI and Nerve Conduction Studies, and the interpretation and significance of the results!