by Frederick C. Hatfield, Ph.D., MSS, and Frederick C. Hatfield II, M.S., SSC
International Sports Sciences Association
Return to Hatfield Home Page
Folks, lets face it! When it comes to others scrutinizing someone elses body -- especially when much of it is exposed -- their focus meanders a bit, going from here to there. But it almost always comes back to the abs. Whether they look rock-hard or pillow-soft, they are the most obvious measure of health and fitness! Any doubts? Compare two people whom youve never met before. One who has a pot belly and the other a washboard. Now, given no additional information, who would you say is in better shape? Hell! These two people look like species from different palnets! Nuff said.
Anatomy is Destiny
The answer to achieving that much-desired washboard appearance lies in studying the anatomy of spinal movement. This is also true of ameliorating or preventing low back pain, a condition of epidemic proportions in our culture. The particular shape any given muscle attains through the administration of progressive resistance is a result of genetic predisposition.
The spine is comprised of 33 vertebrae, only 24 of which form the flexible portion located above the sacrum. There are 7 cervical vertebrae, 12 thoracic vertebrae and 5 lumbar vertebrae.
With the exception of the first two cervical vertebrae, the extent of movement at any vertebral joint is slight, although the total movement at all joints appears to be large. The extent of movement in any given vertebral joint is due to 1) the thickenss of the intervertebral discs (the larger intervertebral discs in the lumbar spine allow more movement there because they compress more), and 2) the tightness of the ligaments holding the vertebrae together (they appear to be slightly less tight in the lumbar spine).
Flexion, lateral flexion and hyperextension in the thoracic region is limited by the presence of downwardly deflected spinous processes (posteriorly) and the ribs (anteriorly). And, lboth rotation and lateral flexion is somewhat limited in the lumbar spine because of the presence of interlocking processes. Rotation is far greater in the thoracic region
Within these anatomical constraints, performing crunchers for abdominal development involves flexion at all of the thoracic and lumbar vertebrae. Study Table One. Youll note that there are five major spinal movements possible:
· Flexion and diagonal flexion;
· extension and diagonal extension (and hyperextension);
· lateral flexion;
· rotation to the same side;
· rotation to the opposite side.
In the case of the spine, rotation is always accompanied by lateral flexion, and lateral flexion is always accompanied by rotation. Circumduction (the movement of any body part which describes a cone) is a combination of flexion, lateral flexion, hyperextension and lateral flexion to the opposite side. There is some rotation involved in spinal circumduction to the extent that it accompanies lateral flexion. All of these movements are accomplished by several muscles acting as a team, each assuming one of six possible roles:
· prime mover (the muscle that produces the most force to move a bone);
· assistant mover (a muscle that assists a prime mover in overcoming resistance);
· antagonist (a muscle that acts in opposition to the movement occurring at the joint);
· stabilizer (a muscle that stabilizes, or fixes, a bone so that movement can occur at another bone articulating with the stabilized bone. For example, the rectus abdominus contracts isometrically in a leg lift to stabilize the pelvis and keep it from tilting forward);
· helping synergist (Two muscles are helping synergists when they cancel each other's normal movement, allowing the desired movement to occur); and
· true synergist (The role of a true synergist is to cancel the undesired movement of a prime mover while not participating in the desired movement).
Innervation for the abdominals is from the anterior divisions of the 7th, 8th, 9th 10th and 11th dorsal nerves (lower intercostal nerves). They terminate in subcutaneous braches (called the anterior cutaneous nerves) near the linea alba (the abdominals midline). The left and right sides of the rectus abdominus are separated from one another by the linea alba, and are therefore independently innervated, just as are all left and right sets of muscles of the trunk (e.g., left and right pecs).
The tendinous intersections you get after stripping away some fat and putting on some muscle are called the linea transversae. These intersections (which rarely extend across the entire abdominal wall) are located on the front of the abdominal wall only -- the tendonous tissue does not separate the left or right recti into functional units. It only appears that way when viewing the washboard effect on an in-shape person.
They are not innervated separately either, as is sometimes assumed (probably because thats the way it looks). Nor do they contract separately.
Electromyographic studies have demonstrated that the upper portion of the recti produced more activity when doing crunches with no weight, but when as little as ten pounds was added, activity was equal throughout the muscle. The same studies demonstrated that reverse crunches can produce greater activity in the lower abs than in the upper abs, but it also produced activity in the obliques. When resistance is applied to the crunch movement, differences in electrical activity disappeared, and contraction became relatively uniform throughout the entire rectus abdominus.
So, contrary to popular belief, all abdominal exercises in which substantial resistance (weight) is being overcome will produce equally strong electromyographic activity throughout the entire muscle. In simple terms, no upper or lower part of a muscle is isolated.
In Table One, I have listed only the prime movers (PM) and assistant movers (Asst.), as these are the roles in question for developing the midsection, particularly the internal obliques, external obliques and rectus abdominus muscles.
MOVEMENTS OF THE THORACIC AND LUMBAR SPINES
Abdominal Group Flexion Extension Lateral Rotation Rotation
Flexion to the to the
same side opposite side
Rectus Abdominis PM Asst.
External Oblique PM PM PM
Internal Oblique PM PM PM
Psoas Asst. Asst.*
Quadratus Lumborum PM
Erector Spinae Group
Iliocostalis Thoracis PM PM PM
Iliocostalis Lumborum PM PM PM
Longissimus Thoracis PM PM PM
Spinalis Thoracis PM PM
Semispinalis Thoracis PM PM
Deep Posterior Spinal Group
Intertransversarii PM PM
Rotatores PM PM
Multifidus PM PM PM
*The psoas may at times become a lumbar spine hyperextender.
Training Your Abs
There are three main muscles which make up your abdominal wall. Two of them (the internal oblique and the external oblique) are important for twisting left and right. The other, the rectus abdominus, is responsible for drawing the pelvis and rib cage closer together, stabilize your pelvis, forced expiration of air, fecae, urine and stomach contents (as in vomiting).
There are many variations of abdominal exercises, and there are just as many abdominal exercise devices. All with any value, however, have one thing in common -- in one way or another, they bring the ribs (origin of the abdominals) and pelvis (insertion) closer together (spinal flexion) by contracting the abdominal muscles. Your internal and external obliques aid in this movement.
These simple actions allow your abs to become a powerful link for your upper and lower body. With this in mind, your abs suddenly have a much more important role than simply flexing the spine or stabilizing your pelvis.
Strong abs have been well-documented to protect and support the lower back. In fact, the only longitudinal muscle responsible for maintaining a proper and healthy lumbar curvature (via stabilizing the pelvis) is your rectus abdominis. Furthermore, tight, firm abs are responsible for holding your internal organs in the proper place. This also helps support the spine .
OK, Im sure by now you got the point: your abs are important! Problem is, what can be done about it? Listen to a hundred people, and youll get a hundred answers! Lets look at some myths that surround abdominal training:
* You can isolate upper and lower abs by doing crunches or reverse crunches. Not necessarily. A study done several years ago demonstrated that the upper portion of the rectus abdominis produced more activity when doing ab crunches with no weight, but when as little as ten pounds was added, activity was equal throughout the muscle. The same study demonstrated that reverse crunches can produce greater activity in the lower abs than in the upper abs, but it also produced activity in the obliques. In simple terms, all abdominal exercises produce activity throughout the muscle; no upper or lower part of a muscle is isolated.
· You should do high repetitions for your abs. Like all other muscles in your body, respond best to PROGRESSIVE RESISTANCE training; you must train your abs like you do the rest of your muscles! And since the primary function of your abs (other than taking on the prized washboard appearance) is to stabilize your pelvis your primary training aim should be in developing the "limit strength" of your abs. So resistance should be used. Endlessly doing reps isn't going to give you any better "washboard" appearance.
· If you use heavy weight, youll never have a small waistline. The abdominal wall is a sheet of muscle, unlike, say, your biceps; theyre not prone to bulge like a bicep is. People with large waistlines tend to have either a large pelvic girdle, a beer belly, lots of fat, or a combination of the three.
· Each of the abdominal segments (i.e., the washboard effect) visible on a fit individual individually flex a different part of the spine. In a recent issue of a popular bobybuilding magazine, it was said that each segment moves or rotates a small part of the spinal column about a point known as a piovot point. There are 4 pivot points [relating to the visible segments] along the spine. As the ab muscles contract, the pivot point moves down. This is definitely wrong! While some vertebrae flex more than others, its a function of the anatomical structure of the spine, and NOT the result of a small portion of the abs contracting. In fact, each of the moveable vertebra in the thoracic and lumbar spine is a pivot point, and there are many more than four!
Many exercises have been developed over the ages to build abs. Some are downright harmful. Some are better than others. But as with all things in life that can be good, better or best, there is always going to be only one best way! But first, lets give due credit to all the others.
Heres the most common crunch exercise: Lying on the floor with your legs draped over a bench, "curl" your head toward your knees and contract your abdominal wall so that your abs pull your ribs closer to your pelvis. Your shoulder girdle and upper back will rise up off the floor in the process. Don't raise your lower back up off the floor. Use a weight plate behind your head or resting on your upper chest if this movement is too easy for you.
There are many crunch machines on the market nowadays that simulate the crunch technique described above. The better known ones are listed in the Table below. Most are good. The best ones, however, add a feature to the exercise that was first seen during the early seventies (in the first generation Nautilus machines) and again three years ago(Scorpion Equipment) -- a head support feature.
Why support the head? Well, since most heads weight from 14 - 16 pounds (more or less), it can be pretty stressful on the muscles and cervical vertebrae supporting that ponderous globe! The sternocleidomastoid, assisted by the 3 scaleni muscles and the prevertebral muscle group (longus coli, longus capitis, rectus capitis anterior and rectus capitis lateralis) are responsible for cervical flexion -- bringing the head forward (or up if youre lying down on your back). Among detrained individuals, this action can cause neck strain resulting in vertebral subluxation.
This exercise has the same basic effect as crunches. However, your knees come toward your face instead of vice versa. Some bodybuilders believe that they can get better "lower abdominal" development with this exercise. I personally doubt it because the research trends to refute this age-old myth. So does empirical observation. Ever see a guy with great washboard upper abs but a saggy lower abdomen? Or vice versa? No such thing! It's more tenable that the entire abdominal wall benefits equally from either.
You can make this exercise more difficult by raising the incline board that you're lying on a bit higher. Begin with your knees and hips completely flexed. When raising your knees toward your face, you shouldn't "swing" them upward, as the ballistic movement will tend to remove some of the desired stress. Instead, raise them up.
The Russians are famous for their great athletes. One of the exercises that all Russian athletes do for the abdominal muscles, the internal oblique muscles and the external oblique muscles has become known as "Russian Twists." Every time you twist, swing a bat, or throw, you use these important muscles. As for its usefulness to bodybuilders, this exercise tightens the entire midsection in a "girdle" effect. Your obliques will probably never grow so large that they bulge out (called Apollos Girdle). But its possible, provided your genetics predispose such massive growth potential.
Your lower back remains in contact with the ground (or, better yet, in contact with an "S.I. pad" tucked under your sacroiliac, or lower back), and your feet are positioned close to your buttocks (knees bent). Holding a small weight directly over your face at arms' length, twist all the way to the right and then to the left several times. Do not allow your torso or shoulders to come in contact with the ground while twisting left and right. And, dont deviate laterally away from your longitudinal axis.
Hanging Leg Raises:
The myth is that hanging while raising your knees upward is going to selectively develop your lower abs. Actually, hanging leg raises is the ultimate version (the highest stress version) of reverse crunches. Re-read the description of reverse crunches, and then attempt to do hanging leg raises. Bet you can't! The only people I've ever seen capable of doing this exercise correctly are accomplished gymnasts.
Your best bet is to do reverse crunches. Remember, flexing your hips during the knee raise is developing your hip flexors (iliopsoas) and your grip (forearm) muscles, NOT your abs!
Of all the exercises I've ever seen, this is perhaps the most ill-conceived. Hanging onto a cable, and then, from a kneeling position (as if praying) pulling downward on it may indeed involve your abs a bit, but really it's your body weight that is pulling the cable down, and NOT your abs. Your abs are only statically contracting in a stabilizing effect while you raise your knees off the floor slightly so your body weight can act on the weighted cable.
You'd be just as well off by merely standing in front of a mirror flexing your abs.
Perhaps staying in the praying position and then praying is the best alternative.
Here's yet another preventive exercise for your spine! This time, you're exercising two very large muscle groups that help stabilize your lower back -- your "obliques" and your "quadratus lumborum" muscles. Both are extremely important to bodybuilders and athletes alike in that they must be strong to prevent back injuries.
Of course, bodybuilders benefit from the fact that (as with Russian Twists) the "Apollos Girdle" effect comes into play. Your toned obliques will tend to "trim" your waist. Simply bend directly sideward toward the side holding the dumbbell. The other arm is behind your head to pre-stretch your targeted obliques.
Some of these exercises are good, meaning theyre better than doing nothing. Some of these exercises are really good. But Ive saved the best for last. All of the aforementioned exercises involve partial movements or movement where either the rectus abdominus, internal obliques or external obliques contract in a static state. These conditions do not produce the best results.
- Adjustable Height Slant Board (old technology dating back to early 1900s)
- Adjustable Height Slant Board With Curved Back (circa 1950s)
- Adjustable Height Slant Board With Inverted "V" To Hook Knees Over (circa 1950s)
- Seated Ab Crunch Machines (Began Appearing As Of Circa 1980)
- The Abdominizer (Rocking Chair Seat -- appeared on TV late 80s)
- Bungee Cord Pulls (Crunches using an anchored cord as resistance)
- Suitcase or Jacknife Raises (Raising both shoulders and less at the same time)
- Medicine Ball Throws (Partner throws a medicine ball to you while youre seated and have feet anchored, you catch and throw it back)
- Ab Flex and Ab Roller (head rest, rocker assembly forces exerciser to maintain good technique while reducing unnecessary and nonproductive strain from neck)
- Ab Crunch (Uses isometric contraction...no better than pressing a brick against your abs)
- Tony Little's cute li'l gimmick (holds knees in flexed position while you do regular crunches, but no better than a short piece of rope looped around your knees)
- Nordic Track's AB Works
Partial Movements Versus Full Range Movements:
Partial movements have their place in weight training. Bodybuilders use them when working on limit strength or sticking points, and athletes in many sports use them for both these purposes as well as in simulating sports-specific movements. However, it's safe to say that full range movements are generally more productive in improving strength, tone and mass. So, let's explore one of the reasons why full range movements are so productive. It has to do with the amount of work being accomplished.
Let's say you squat with 500 pounds, but only go half way down. Your normal "stroke" (distance over which you move the weight) equals two feet, but you only go one foot down. And, let's say the upward movement takes one second.
Power = force X distance divided by time;
P = 500 X 1 foot divided by 1 second = 500.
Now, let's say you did the full squat movement of two feet in the same amount of time:
P = 500 X 2 feet divided by 1 second = 1000.
Clearly, you've done twice the amount of work:
Work = force X distance;
Work = 500 X 2 = 1000.
Even if it took you twice the amount of time to perform the full range of movement, you've still done twice the work:
P = 500 X 2 feet divided by 2 seconds = 500, but
Work = 500 X 2 feet = 1000.
You don't have to be a rocket scientist to understand that twice the work makes for a much more efficient workout! But, let's look at one more reason why full range movements are often more productive in bodybuilding and sports. This time, we'll look at what's going on at the cellular level -- inside the contracting muscle itself.
When you stretch a muscle to it's full length, the myofibrillar elements (actin and myosin) are fully stretched. That means that the overlap between the actin and myosin myofibrils is minimal, and you're not as capable of producing force. Remember, the "cross-bridging" going on between the actin and myosin strands is what causes contraction.
Over a few weeks of time, however, the actin and myosin myofibrils "adapt" to this new requirement of having to produce force while stretched. They do so by growing longer in an attempt to increase the amount of overlap between them. This, of course, has the net effect of increasing the amount of force you can generate even while stretched!
Applying The Full-Range Principle to Abdominal Training:
I would like to introduce to you the only machine on the market which offers a full-range while doing abdominal crunches. The secret is the curved back padding.
There are some good reasons why the curved back design is so effective in ab development. One is the therapeutic effect it has on your lower back. The position of the overhead pulley is such that an unloading (or decompression) of the vertebrae comprising the spine is accomplished. While the abs are contracting, effecting this mild decompression, the effect on the intervertebral discs is such that trauma from compressive and shearing forces is eliminated. Imagine, for example, performing ab crunches while hanging upside down. Your body weight decompresses your spine. With this patented design, this is accomplished with the weight at the end of the pulley cable.
Of course, another is that the amount of work you're accomplishing is virtually doubled.
Your thoracic vertebral joints are capable of a few degrees of flexion and hyperextension, and the lumbar vertabrae slightly more. The patented curvature of the ab machine's bench is precisely matched to the range of movement Mother Nature intended for your thoracic and lumbar spines. This ensures non-traumatic movement from an unforced hyperextended position to an unforced hyperflexed position -- which further ensures the greatest possible range of motion and the least possible intervertebral trauma.
For those of you with "bad backs" (almost all of you, if statistics can be trusted), it has become axiomatic that ab work is the best therapy for your condition. And, for those of you whose backs are virgin to troublesome herniations, subluxations and ruptures, it is as much the case for prevention.
A few points to ponder:
* You can't put your obese client on the ground to do crunches without causing severe psychological trauma (it's embarrassing to them when they try to get up or down);
· The other ab machines on the market are difficult to get into and out of, are principally hip flexors (the abs are forced to statically contract while the iliopsoas concentrically contracts to bring your torso forward or your knees toward your chest), and -- if at all -- involve only a half range movement capability;
· Full range crunches are 100 percent more productive than half range crunches;
* Decompression of the intervertebral discs during the crunch movement is desirable;
* Abdominal muscle cells are no different from other muscles' cells, and therefore will respond optimally based on the specific fiber type(s) comprising the muscle;
* Prestretch ab crunchers is the ONLY exercise capable of solving all these problems.
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