Trapezius

If trapezius: innervation is the spinal accessory nerve (CN XI); actions include scapular rotation/elevation/retraction

What our notes say

If trapezius: innervation is the spinal accessory nerve (CN XI); actions include scapular rotation/elevation/retraction (Aponeurosis — Anatomy Question Bank)
o Trapezius, percussing downwards on lung apex o Above level of spine of scapula o At intervals of 4-5 cm from below the level of spine of scapula down to the 11th rib. (Examination of Respiratory system — Past Paper Questions & Answers)
Ipsilateral cerebral hemisphere supplies contralateral trapezius but ipsilateral sternocleidomastoid — a single UMN lesion can therefore produce signs on both sides (CNS History Taking & Neurological Exam Guide | Clinical Skills)
Ipsilateral hemisphere → contralateral trapezius + ipsilateral SCM (single UMN = bilateral signs) (CNS & Abdominal Exam: Clinical Techniques, History & Neurology)
Ask patient to shrug (trapezius) and turn head against resistance (SCM) (CNS & Abdominal Exam: Clinical Techniques, History & Neurology)