I was demonstrating Range of Motion in an Assessment class for massage students.  One student had been in an auto accident which fractured her lower cervical vertebrae and injured her shoulder.  After 6 years of physical therapy her shoulder abduction was still restricted to 90 degrees – the arm horizontal to the floor. Just for fun I did a quick (and rather sloppy) IRT to the shoulder which resulted in an increase to 110 degrees abduction.  The following week I remembered to do IRT on the cervical vertebrae and she immediately regained full abduction – 180 degrees.  There was no restriction from the lack of performing that motion for 6 years.