When you talk about core training, the phrase "lateral flexion" doesn't roll off your tongue; however, it is an essential component of building a strong trunk that can help you execute athletic and daily activities with ease, finesse and less risk of injury. Lateral flexion involves multiple muscles of the torso and can help strengthen and stretch your spine.
Lateral flexion involves side bending away from the midline of the body, called abduction, and then straightening back to the center, called adduction. Along with rotation, forward flexion and extension, it is one of the four movements possible by the spine. You use your internal and external obliques at the sides of your abdominals; the rectus abdominus, which is the superficial front abdominal muscle; and the transverse abdominis, a deep stabilizing abdominal muscle, to complete the action. In addition, the quadratus lumborum, muscles located deep in the lower back; the transversospinalis, short muscles found between the vertebrae; and the erector spinae, a group of muscles that lie along the spine.
Slimming the Waist
Side bending, or lateral flexion, does not effectively tone your waist. Spot training isn't possible. Len Kravitz, a professor at the University of New Mexico, also notes that the deeper spinal muscles are more active and efficient during side bending than the abdominal muscles. If you feel sore after a lateral flexion workout, it isn't because you've effectively trimmed your sides. Kravitz says it is usually because you've overstretched the obliques and done the movements too fast.
Increased Range of Motion
Lateral flexion is helpful in increasing the range of motion of the spine. Do the movements in a slow, deliberate manner and alternate from side to side for the most effect. You can perform lateral flexion standing, seated or lying on the floor.
You also can perform lateral flexion at the neck to work the sternocleidomastoid muscle, one of the largest, most superficial muscles of the neck. Lateral neck flexion involves bending the head to the side, so the ear drops toward the shoulder and then returns to center. When you do this move, you also activate the splenius, located at the upper cervical spine; the erector spinae; the levator scapulae, muscles at the side of the neck that elevate the shoulder blades; and the upper part of the trapezius, a trapezoid-shaped upper-back muscle between the shoulder blades. You use lateral neck flexion to improve neck range of motion and to stretch out tight muscles.