Spinal pa of accessory nerve supplies
Sternocleidomastoid and trapezius are supplied by spinal accessory nerve. Both of them develop from brachial arch mesoderm.It is tested by turning the neck against resistance.B D Chaurasia 7th edition Page no: 65 ( refer head and neck volume )
Platysma
Sternocleidomastoid
Stylohyoid
Diagastric
Upper limb