What Other Muscles Should Be Worked Following An Ab Workout?

It's common to train the abdominal muscles and neglect the back extensors and quadratus lumborum. The resulting imbalance contributes to lower back pain. Also, the connective tissue that surrounds the abdominal muscles extends into the diaphragm above and the pelvic muscles below the abdominal organs. To be balanced, you need to work the back extensor muscles, diaphragm and pelvic muscles in addition to the abdominal muscles.

Abdominal Muscles

The rectus abdominis, internal oblique and external oblique muscles form the front girdle of the abdomen. The rectus abdominis muscle extends from the lower ribs to the pubic arch and it works by pulling the rib cage closer to the pelvis so that you bend forward at the waist. The internal and external oblique muscles are located on each side of the rectus abdominis muscle. They also connect the lower ribs to the pelvis. These muscles help you flex the spine -- bend forward -- and they help you twist the spine at the waist. Working the abdominal muscles helps to trim your waist and flatten your abdomen.

Back Muscles

The back extensor muscles -- the erector spinae and multifidus muscles -- provide posterior support for the spinal column and control forward flexion. The erector spinae is a group of muscles including the spinalis, longissimus dorsi and iliocostalis. The lumbar, or low back, portions of these muscles oppose the abdominal muscles so that you stand erect and balanced. The quadratus lumborum muscles connect the posterior ribs to the hip bone, as well as the erector spinae muscles to the oblique muscles. The quadratus lumborum helps to maintain your posture and works with the obliques in bending sideways -- lateral flexion.

Considerations

Stress on the vertebral discs varies depending on the balance of the muscles that move the spine. When all the muscles are balanced, the pressure on the discs is balanced. Weak back extensor muscles can't balance the abdominal muscles adequately. Working the abdominal muscles without also working the back extensors puts stress on the anterior edge of the spinal discs, causing them to bulge backward.

Recommendations

Start with a balanced routine of spinal flexion, rotation and lateral flexion to work the abdominal muscles. Add spinal extensions to your routine to work the erector spinae and quadratus lumborum muscles. Standing contractions of the rectus abdominis and oblique muscles is safest, although crunches also are safe if done properly. Avoid sit-ups, which involve the hip flexors and put additional pressure on the low back. Slow, controlled twists and sideways bends strengthen the oblique and quadratus lumborum muscles. Prone upper-body lifts help to strengthen the erector spinae muscles.