Why a post about ab machines and abdominal muscle anatomy? Well, everyone wants a trim, firm abdomen (if not an absolute ripped 6 pack). However it’s pretty obvious that most people fall sadly short of that goal. Maybe that’s why it’s so highly valued and why you see so much hype around various approaches to abdominal fitness.
While information is good, too much can be overwhelming. To help you sort through it all, I though it would be a good idea to get back to basics and review abdominal muscle anatomy, especially as it relates to ab machines.
I guess we should begin with the muscle most people think of when they think of a fit belly: the one on the front of the abdomen, the rectus abdominus. This is the muscle that, when well-developed and not hidden under fat, people refer to as a “6 pack” (in point of fact, there are normally 8 segments of the rectus muscle, but why quibble about details).
The muscle runs from the bottom of the rib cage to the pelvis. Like any muscle, when it contract it shortens the distance between its two points of attachment. The classic move to develop this muscle was the sit-up.
However, as you imagine the motion of the sit up, you’ll note that shortening the distance between the rib cage and the pelvis is only a small part of the movement involved. Hip flexion, which uses a whole different set of muscles, constitutes a major part of the movement.
For this reason, various people have recommended dropping sit ups from your fitness routine, replacing them with crunches in one form or another. Crunches focus on rectus contraction. While that’s true, that means that crunches are an isolation exercise. That’s a disadvantage because in the real world, muscles rarely work in isolation. I’ll more to say about that in a moment.
Another rap against sit ups is that they can possibly put you back at risk. This is because major hip flexor muscles run along either side of the spine. As these muscles contract during a sit up they can generate compressive forces along the spine, putting pressure on the disks. In addition, there’s a risk of developing an abnormal curvature of the spine.
In truth, most of the problem associated with sit ups are caused more by people doing them with poor form, often because they have inadequate abdominal muscle strength to do them properly. This causes over use of the hip flexors and the problems caused by muscle imbalance I just mentioned.
You can think of a sit up as an advanced dynamic exercise, in the same way you might think of a power clean or snatch. While such exercises are extremely effective, and moreover develop complex muscular coordination, they can be dangerous if form is poor.
If you want to use sit ups as part of your abdominal routine, here are some tips to avoid injury.
First, perform them on a lightly padded surface, such as a carpet, yoga pad, wrestling map, etc., rather than a hard floor. Do not use anything to anchor your feet. If you can’t do them without an anchor it means your abdominal muscles are not as yet strong enough to do them correctly. Do other exercises to build strength and try again in a couple of weeks.
Placing a small rolled towel (4 inches or so in diameter) under the small of your back helps maintain proper alignment. If you have $30 or so to spend, you can buy a pad designed for this purpose.
Finally, cross your arms over your chest rather than clasping them behind your neck. The later is likely to lead to neck strain.
An advantage of a good ab machine (and there are several on the market) are that they overcome most of the weaknesses of both crunches and sit ups. They can develop integrated, multi-muscle development, including the rectus, while almost “forcing” proper form so injury is avoided.
Lets move on to some of the other abdominal muscles.
Unless you’ve been hiding under a rock in the middle of the fitness world, you’ve probably at least heard something about “the core” in the last few years. When most people use the phrase, they are thinking of muscles that stabilize the body.
Some used it to refer to what used to be called the obliques – the muscles on either side of the abdomen. I think it best to consider the core as a functional rather than an anatomic concept. Before I explain what I mean by that, let’s get back to the anatomy.
While the rectus muscles get all the attention, they’re only part of the abdominal musculature. Three major muscles compose what is sometimes collectively referred to as the obliques. All of these muscles run generally from the back the outside edge of the rectus muscles.
The inner most of these muscles is the transverse abdominus. When you’re standing, the fibers of this muscle run parallel to the floor.
The next layer as you move out toward the skin is the internal oblique. These fibers slant upward going from back to front.
The final layer is the external oblique. Fibers of the external oblique slant downward, crisscrossing those of the internal oblique.
I think you can imagine how these multiple layers of fibers all contracting in different directions allow for a great mobility in multiple planes of action.
Other muscles that make up the core lie along the spine. They help to stabilize it.
One way of thinking about the core is that it connects the upper and lower part of the body. Imagine for a moment that you’ve used the bench press as the main way of developing your upper body strength (unfortunately, this is all too true for a lot of guys). Also imagine that you’ve developed your legs slowly using a leg press machine.
With both of those exercises, the body is supported by a bench or seek and the strength development is confined to the arms and legs respectively. You may get quite strong but the strength will be limited to specific muscle groups.
Now imagine that someone who’s trained like this is trying to help push the car out of the ditch. While they may have great strength in their legs and arms and chest they won’t get maximum effect because they aren’t well connected to each other. The core muscles acting together create that connection.
That’s why it’s crucial for anyone who’s interested in functional strength, and certainly for any athlete, to develop their core, which includes all the abdominal muscles.
As an aside, I’ll admit to having spent too much time in the past doing bench presses. These days I spend a lot more time doing different variations of push-ups. The standard push-up is a great core exercise in itself and there are lots of variations.
I think developing a well-rounded core is one of the great advantages of a well-designed ab machine. You can certainly do it with standard exercises would have machine makes it possible to get the muscles from multiple directions and to do it safely.
If you do want to develop your obliques side planks are good way to go. If you want to develop greater strength and athletic capabilities exercises that work across the body with a twisting motion, such as wood choppers using a cable machine, get the job done.
I hope this review of abdominal anatomy and how it relates to performance helps you design the ab program that works for you.
If you’re considering getting a machine, check out what you can learn from ab glider reviews.