Anatomy Of The Trapezius Muscle - Everything You Need To Know - Dr. Nabil Ebraheim

Dr. Ebraheim’s educational animated video describes anatomy of the trapezius muscle.

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Anatomy of the Trapezius Muscle
The trapezius is a large superficial muscle that extends from the back of the skull, back of the neck, and back of the thorax. The upper fibers of the trapezius muscle arise from the external occipital protuberance and the medial third of the superior nuchal line. The middle fibers arise from the ligamentum nuchae and the spinous process of C7. The lower fibers arise from the spinous processes and supraspinous ligaments of all twelve thoracic vertebrae. The trapezius is inserted into the lateral third of the clavicle, and from the acromion process and the spine of the scapula. The trapezius muscle allows for rotation and lift of the scapula. Dysfunction of the trapezius muscle may cause lateral winging of the scapula. Winging can occur after radical neck surgery, but it usually occurs after biopsy or tumor dissection. The spinal accessory nerve will be injured, and the patient will have difficulty with overhead activity. If injury to the spinal accessory nerve occurs early, explore the nerve. If injury is late, do a muscle transfer. The spinal accessory nerve provides motor innervation to the sternocleidomastoid and the trapezius muscle. The spinal accessory nerve courses obliquely across the posterior triangle on the surface of the levator scapula muscle and reaches the trapezius. Within the posterior triangle of the neck, the nerve is vulnerable since it is superficial and only covered by skin and subcutaneous fascia. Extreme caution should be taken for any surgical procedure done in the posterior triangle of the neck.