Stand up straight and position a strap or belt across the top of your shoulder.
The middle of the strap should lie across your shoulder, near the base of your neck, on the same side as the muscles you would like to stretch.
Hold the front end of the strap in the same hand, and hold the other end, dangling down your back, with your opposite hand.
Bring this hand around to join your other hand.
Keeping some downward tension in the strap, tilt your head away from the strap, then add on a slight tilt backward.
You should feel a stretch down the front side of your neck on the same side as the strap is positioned.
Hold this position.
