The accessory nerve also referred
The accessory nerve also referred to as the spinal accessory nerve, innervates the sadomasochistic and trapeziums muscles. When both the internationalists contract, the head flexes forward; individually, they cause rotation to the opposite side. The trapeziums can act as an antagonist, causing extension and hyperextension of the neck. These two superficial muscles are important for changing the position of the head. Both muscles also receive input from cervical spinal nerves.
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