During some backyard football, you dove for the ball and dis…

During some backyard football, you dove for the ball and dislocated your shoulder. You were relieved when you stood up and felt it slide back into place. Unfortunately, after you started to move your shoulder around, you notice you could not abduct it past 15 degrees. What nerve of the brachial plexus did you injure?

A 14-year-old patient reports to the emergency room followin…

A 14-year-old patient reports to the emergency room following a cycling accident where he fell off his bike and struck a tree with his arm.  X-rays show that this patient has a fractured humerus. The patient presents with significant weakness with elbow and wrist extension. Based on the patient’s motor weakness, you suspect that the fracture occurred in the region of which bony landmark of the humerus? (Hint: First ask yourself which terminal branch of the brachial plexus is likely affected.)