A 43 year old woman came with a large abscess in the middle of the right posterior triangle of the neck. The physician incised and drained the abscess. Few days later the patient noticed that she could not extend her right hand above her head to brush her hair. Which of the following has likely occurred? 1. Damage to scalenus medius 2. Injury to suprascapular nerve 3. Cut to spinal part of accessory nerve 4. Spread of infection to shoulder joint
I think 3rd option but i don't get how it affects the overhead abduction
The spinal part of accessory nerve supplies trapezius and sternocleidomastoid. The upper fibres of trapezius raise the acromion process and the lower fibres depress the medial end of spine of scapula. This laterally rotates the scapula — which is essential for abduction of upper limb above 90°
