Please note: This is a companion version & not the original book. Sample Book Insights:#1 The neck muscles come in right and left pairings, so all the neck muscles are involved in lateral flexion and extension. Neck flexion is limited not only by the stiffness of the posterior muscles but also by the stiffness of the posterior ligaments, the strength of the flexor muscles, the alignment of the vertebral bodies with the adjacent vertebrae, and the compressibility of the anterior portions of the intervertebral discs.#2 Stretching the neck can be dangerous if not done properly. Some stretches of the neck use a plow position in which the back of the head lies on a surface, with the trunk nearly perpendicular. This position can generate high stress at the bending point, especially in people with low neck flexibility.#3 The stretch is done while seated or standing, and should not be done while hunching up the shoulders. The neck extensor muscles must remain loose to maintain proper posture, and proper posture can help reduce muscle strain and tightness.#4 After the neck extensors become flexible, you can progress from stretching both sides of the neck simultaneously to stretching the left and right sides individually. Stretching one side at a time allows you to apply a greater stretch on the muscles.