What it Does
Stretch external and deep neck muscles, while activating the weaker deep neck muscles.
How it Does It
The angle of the neck creates the stretch. The strengthening of the deep neck muscles seems to happen (we discovered this phenomenon by accident so still need to work out the exact mechanical explanation) due to the body's desire to keep the neck straight, and while the compensation muscles are being stretched the weaker deep neck muscles get a change to activate.
Strengthening and balancing the deep neck muscles can lead to a variety of physical and psychological benefits.