The posterior triangle of the neck is bounded by the following Except

Posterior Triangle The posterior triangle is a space on the side of the neck situated behind the sternocleidomastoid muscle. Boundaries Anterior: Posterior border of sternocleidomastoid Posterior :Anterior border of trapezius Inferior or base: Middle one- third of clavicle Apex lies on the superior nuchal line where the trapezius And sternocleidomastoid meet Roof : Investing layer Floor: Formed by a prevertebral layer of deep cervical fascia covering the following muscle: a. splenius capitisb. Levator scapulae; c. Scalenus medius and occasionally scalenus posterior.