I found out I had a pinched nerve in my neck a few years ago which caused terrible muscle spasms in my  shoulder.  A doctor addressed the issue of the pinched nerve in my neck, but the PTs addressed all of the residual pain in my shoulder and arms caused by the agony of the pinched nerve.  Dry needling was one of the techniques they used to treat me. The use of dry needling shortened the amount of time I needed in PT and provided much quicker relief to my pain than other PT modalities did.  It was effective, quick and I am certain it also saved my insurance company a lot of money..