PLE-541

PLE-541

A 55-year-old female, who is obese and has been diagnosed with bilateral knee osteoarthritis, has been using crutches for a year to assist with her mobility. She presents to you with a complaint of difficulty in abducting her right shoulder. Upon examination, you observe a loss of the rounded contour of the right shoulder and a lack of sensation in the lower half of the right deltoid. Which nerve is likely to have been affected?