i.e. (Accessory): (843- Snell 8th) (132-133- BDC-8 5th ed)When a superficial incision is made in the posterior triangle, the nerve most likely to be injured is spinal accessory nerve, because it runs through a tunnel in the fascia forming the roof of the triangle.In the posterior triangle of the neck, the spinal part of the accessory nerve is relatively superficial as it emerges from the posterior border of the stemocleido mastoid and runs down ward and back ward to pass beneath the anterior border of the trapezius.POSTERIOR TRIANGLEThe posterior triangle is bounded posteriorly by the trapezius muscle, anteriorly by the sternocleidomastoid muscle and inferiorly by the clavicle. The posterior triangle of the neck is further subdivided by the inferior belly of the omohyoid muscle into a large occipital triangle above and a small supraclavicular triangle below.Nerves in the posterior triangle of neck (only motor nerve)* Spinal accessory nerve* Two small branches to levator scapulae* Nerve to Rhomboide* Nerve to serratus anterior* Nerve to subclavius* Suprascapular nerve