This is a technique that helps reduce cervicogenic headaches (tension headaches). 

The objective with this stretch is to improve flexibility of the neck/upper trap muscles. This is not an aggressive stretch, it is to be performed slowly and without pain. 

Flexibility isn't always the problem with neck pain, sometimes it is the lack of muscle firing of the deep stabilizer muscles, this exercise addresses that issue. Only apply approx. 5-10 lbs of pressure in each direction. 5 -10 reps per direction