Sally, 9-year-old girl, just did an awesome backflip on her trampoline. Instead of landing in a similarly awesome manner, she miscalculated and landed on her neck. Sally stood up with pain in her neck and does not appear to be able to extend her left arm very well. An x-ray shows a fracture of her C6 vertebrae that is compressing down on her C7 vertebrae impacting the spinal nerve located between C6 and C7 vertebrae. Which spinal nerve did Sally likely injure

The C7 spinal nerve exits on each side through the intervertebral foramen between the C6 and C7 vertebrae. The C7 spinal nerve has both a sensory root which is composed of sensory fibers and a motor root. This nerve is required to control motor functions including shoulder movement (i.e., adduction, abduction and rotation). The C7 dermatome is a region of skin that receives sensory inputs from the C7 spinal nerve.