Advertisers have hooked people on the thought that the only reason they should go to the gym is to get a "six-pack". Most people that I talk to don't seem to know other muscle groups even exist!
Everyday I see some type of new gimmick, device, or exercise system that supposedly gives you a ripped waistline. Most of the individuals that market these devices know absolutely nothing about anatomy and kinesiology, but are great at advertising.
How many of those devices are really producing ripped abs? My guess is very few, if any. Improper training of the abdominal region can alter function of your organs, distort your posture, and cause pain plus dysfunction! It is time to make clear the true principles of training this region.
In this article, we will look into the structure and function of the abdominal wall, the consequences of faulty training, and how to properly train for maximum function and strength. So without further delay, let's get to it!
The Anatomy & Functions Of The Abdominals
It is always important to start with anatomy and function of a muscle group to allow better understanding of the concepts that will be presented later. There are four major muscle groups in the abdominal region, and one muscle that is a synergist to the abdominals that we will discuss here.
The rectus abdominus, better known as the "six-pack" muscle, is a superficial muscle. The muscle originates at the pubic symphysis and inserts into the costal cartilages of the 5th-7th ribs and the xyphoid process. Its primary function is to flex the trunk if the pelvis is fixed (as in a sit up). If the trunk is fixed, it will posteriorly rotate the pelvis. The rectus abdominus, when contracted maximally, will flex the lumbar spine approximately 30 degrees.
The external obliques are also a superficial muscle that is found just laterally to the rectus abdominus. They originate from the external surfaces of the lower 8 ribs, and insert into the anterior half of the outer lip of the iliac crest and the aponeurosis of the anterior abdominal wall. Its function includes flexing the trunk (in bilateral contraction), posterior pelvic tilt, same side flexion, and rotation of the trunk to the opposite side (during unilateral contraction). The external obliques are the largest of the abdominal muscles.
The internal obliques lie deep to the external obliques. They originate from the lumbar spine fascia, anterior iliac crest, and the lateral two thirds of the inguinal ligament, and insert into the 9th-12th ribs and the linea alba. Their function is to flex the spine (during bilateral contraction), same side rotation (during unilateral contraction), and act as a synergist to the external oblique during same side flexion, and during rotation to the opposite direction (during right rotation, the right internal oblique works with the left external oblique).
Upper And Lower Abs
The rectus abominus has 8 sources of innervation (T5/6-T12/L1), while the obliques have innervation from T7-T12. There is partitioning in the abdominal wall, as it performs roles as both a stabilizer and a prime mover-often in the same movement. Below the umbilicus these muscles are innervated by the ilioinguinal and iliohypogastric nerves (which are predominately L1 in origin). This is how to separate the upper and lower regions of the abdomen neurologically. (From Paul Chek's Scientific Core Conditioning correspondence course, 1992,1998).
The transverse abdominus lies deep to all of the other abdominal muscles, and therefore cannot be palpated. It originates on the internal surfaces of the 7th-12th ribs, the thoraco-lumbar fascia, and the iliac crest, and inserts into the linea alba. Its function is to increase intra-abdominal pressure by applying lateral traction to the lumbo-dorsal fascia. It is considered to be a major stabilizer of the lower back.
Iliopsoas (Or Psoas)
The psoas also lies deep to the abdominal muscles. It originates on all five lumbar vertebra and inserts on the lesser trochanter of the femur. The function of the psoas is to flex the trunk when the feet are anchored (as in a sit-up), flex the hip when the trunk is anchored, or lumbar side flexion (during unilateral contraction). Bilateral contraction of the psoas will cause the pelvis to tip forward (anterior tilt).
In a future article, we plan to bring you more info on how the abdominals interact with other muscles in the flexor chain, and how imbalances in this chain can cause postural distortion, respiratory dysfunction, back pain, neck pain, and disrupt the function of your internal organs.
To Learn More About Abs Anatomy & Exercises, Click Here.
- Chek, Paul. The Golf Biomechanics Manual: Whole in One Golf Conditioning. Encinitas, CA: A CHEK Institute Publication, 1999.
- Chek, Paul. Equal, But Not The Same, Considerations For Training Females. Correspondence course and videocassette, A CHEK Institute Publication and Production, 1996.
- Chek, Paul. Scientific Core Conditioning. Correspondence course and videocassette, A CHEK Institute Publication and Production, 1992, 1998, 1999.
- Chek, Paul. Scientific Back Training. Correspondence course and videocassette, A CHEK Institute Publication and Production, 1995.
- Kendall, Florence Peterson. McCreary, Elizabeth Kendall. Muscles Testing and Function. Fourth Edition. Baltimore, Maryland: Williams and Wilkens, 1993.
- Magee, David J. Orthopedic Physical Assessment. Fourth Edition. Philadelphia, Pennsylvania, Saunders Elsevier Sciences, 2002.