Spinal Accessory Nerve Block for Myofascial Pain on POCUS The needle is being viewed in-plane, approaching the posterior aspect of the sternocleidomastoid muscle. This is a spinal accessory nerve block that effectively relieves myofascial trapezius muscle pain. Dr. Meghan Herbst @EUSmkh #Spinal #Accessory #Nerve #Block #POCUS #Pain #clinical #ultrasound #anesthesia #MSK