A 17-year-old male presents to the Emergency Department by ambulance after suffering trauma in a high school football game. The patient is in a cervical collar and Emergency Medical Services personnel states that the patient was unconscious on initial presentation. The patient is currently alert and oriented and states he is in severe pain and is holding his right upper extremity. Physical examination reveals 2+ peripheral pulses bilaterally and decreased sensation to light touch of the right upper extremity. Which of the following physical exam findings would be concerning for a lower motor neuron lesion?