Free Stretching Anatomy-2nd Edition by Arnold Nelson, Jouko Kokkonen

slowly and not let the back straighten. By bringing the legs to the chest, you can easily raise the buttocks off the floor and prevent a straight back by allowing the spinal column to curl. Finally, do not try to bring the knees too far below the chest (do not try to touch the knees to the floor), as this could negate the safety benefits of this stretch.

Beginner Lower-Trunk Lateral Flexor Stretch

Execution
     
Sit upright in a chair.
Interlock the hands behind the head, with the elbows in a straight line across the shoulders.
While keeping both elbows back and in a straight line, laterally flex the waist and move the right elbow toward the right hip.
Repeat these steps for the opposite side.
Muscles Stretched
     
Most-stretched muscles: Left external oblique, left internal oblique, left rotatores
Less-stretched muscles: Left intertransversarii, left multifidus, left quadratus lumborum
Stretch Notes
Research has shown that the inability to do lateral flexion is a risk indicator for recurrent nonspecific low-back pain and injuries. Also, athletes who perform overhead actions for maximum distance or force, such as baseball players, football quarterbacks, and javelin throwers, need loose lateral flexors. They are also important for overhead hitting (e.g., racket-sport serves and smashes) and when reaching up as high as possible (e.g., rebounding a basketball or spiking a volleyball). Gymnasts, modern and ballet dancers, and divers need these muscles to be loose. In addition, tight lateral flexors can lead to a form of scoliosis. The quadratus lumborum’s only action is lateral flexion, and tightness in this muscle results in a loss of lateral stability of the spine, causing the spine to curve to the left or right.
Flexing or extending at the waist will reduce this stretch’s effectiveness. Also, keep the buttocks and thighs in complete contact with the chair. The closer the elbow gets to the floor, the harder it will be to remain seated in the chair. Wrapping the lower legs and feet around the chair legs will help keep the buttocks and thighs in contact with the seat.

Intermediate Lower-Trunk Lateral Flexor Stretch

Execution
     
Stand upright with the feet together and the left side of the body facing a wall about an arm’s length away.
Place the palm of the left hand on the wall at shoulder height. Place the heel of the right hand at the hip joint.
While keeping the legs straight, contract the buttocks and slightly rotate the hips in toward the wall.
Use the right hand to push the right hip toward the wall.
Repeat these steps for the opposite side.
Muscles Stretched
     
Most-stretched muscles: Left external oblique, left internal oblique, left rotatores
Less-stretched muscles: Left intertransversarii, left multifidus, left quadratus lumborum
Stretch Notes
Many sports rely on lateral trunk flexion. Since many of these activities stress one side of the body more than the other, it is easy for the two sides of the body to become unbalanced. The active side can become tight from being overworked. If the nonworking side goes unused for extended periods, the muscles can become short. Unbalanced body sides also can result from heavy lifting, especially if one side is substantially stronger, or from participation in activities such as martial arts and football in which the body receives heavy blows. This exercise is better suited than the basic lower-trunk lateral flexor stretch for restoring flexibility because the person is in a standing position similar to the detailed sports activities.
It is very easy to lose balance while doing this exercise, so stand on a nonskid surface. Keep the left arm straight, but do not lock the elbow. You can increase the amount of stretch by moving the feet farther from the wall, by resting the left forearm instead of the hand on the wall, or both.

Advanced Standing Lower-Trunk Lateral Flexor Stretch

Execution
     
Stand upright with legs 2 to 3 feet apart (60 to 90 cm), with the right foot about