What Is the Upper Trapezius?

Trapezius is located under the skin of the neck and back, with a triangle on one side and an oblong square on the left and right sides. The trapezius muscles connect the shoulder strap bones with the skull base and vertebrae, and play a role of suspending the shoulder strap bones.

Trapezius is located under the skin of the neck and back, with a triangle on one side and an oblong square on the left and right sides. The trapezius muscles connect the shoulder strap bones with the skull base and vertebrae, and play a role of suspending the shoulder strap bones.

Chinese name

Trapezius

Foreign name

Trapezius

Category

muscle

Location

Superficial muscles of the upper and middle backs

Shape

Outer occipital bulge, top line

Trapezius kinematics anatomy

It starts from the occipital bulge, the upper neck line, the neck ligament, the 7th cervical vertebra, and all thoracic spinous processes. The fibers are divided into upper, middle and lower parts, which stop at the lateral 1/3 of the clavicle, the scapula and the acromion. When near fixed, the upper fiber shrinks, causing the scapula to lift up, gyrating, and retracting; the middle fiber shrinks, causing the scapula to retract and gyrating; the lower fiber shrinks, causing the scapula to descend and swing upward. When distantly fixed, one side contracts, making the head flex to the ipsilateral side and swirling to the opposite side; both sides contract, making the head and spine straight. Developing this muscle in adolescents can prevent and correct hump.

Arteries that supply trapezius

It is mainly the transverse carotid artery, and there are some small minor arteries. The transverse carotid arteries mostly originate from the thyroid cervical spine or subclavian artery, and travel outward through the brachial plexus (or over the front) to the anterior margin of the scapular levator muscle, divided into superficial and deep branches, which are distributed in the trapezius muscle. On the deep side, the deep branches line the deep side of the scapular levator muscle and the rhomboid muscle. There is an anastomosis between the anterior and deep branches, and they are anastomosed with the superior scapular artery and the rotator scapular artery to form a scapular artery network.

Trapezius muscle

The venous blood of the trapezius muscle mainly returns to the external jugular vein and subclavian vein through the transverse jugular vein and superior scapular vein. The carotid transverse vein can be accompanied by 1 to 3 veins. There are 57 arteries accompanied by 1 vein, accounting for 89.06% of the arteries; 5 arteries accompanied by 2 veins. It accounts for 7.81%; there are 2 arteries accompanied by 3 veins, accounting for 3.13%.

Trapezius muscle

The trapezius muscle is innervated by the 11th pair of cerebral nerves and the third and fourth cervical nerves. The accessory nerve enters the deep side of the muscle through the anterior edge of the trapezius muscle, and accompanies the superficial branch of the transverse carotid artery, passes near the root of the scapula, and then accompanies the deep branch of the transverse carotid artery. The length of 56 accessory nerves from the posterior edge of the sternocleidomastoid muscle to the anterior edge of the trapezius muscle was (45.01 ± 1.10) mm, and the thickness of the accessory nerves was (2.12 ± 0.07) mm. The branches of the anterior branch of the third and fourth cervical nerves, after coming out from the cervical plexus, reach down to the anterior edge of the trapezius muscle and contract with the accessory nerves.