Understanding how muscle contraction works can greatly help you in working the muscles you are trying to work. As an example let’s look at the bicep muscle. The bicep muscles (there are 2, hence bicep) originate at the coracoid process (part of the scapula, the shoulder blade) and has an insertion point of the radius bone in your lower arm. To work the bicep muscles we grab an appropriate weight be it a barbell or dumbbell and starting with our arm straight we then bend our arm, bringing the weight up towards our shoulder. Most muscles are worked this way. The muscles will typically cross a joint (the elbow in this example) and we work that muscle by using the joint it crosses. The same with the tricep muscles originating from the humerus (upper arm) and having an insertion point of the ulna (lower arm) crossing the elbow joint. We work the tricep muscles inversely to how we work the bicep muscles. Makes sense.
So knowing this can help in how you work the muscles as the primary movers or secondary movers or stabilizers. Our abdominal muscles are a good example of this. Our abdominal muscles are comprised of the rectus abdominis and the transversus abdominis. The rectus abdominis is what we all understand as our abs, this muscle group is what we see when we have an 8 pack (tough to get, most only achieve a 6 pack). The transversus abdominis we don’t notice that much as sits just below and beind the rectus abdominis but also behind the external and internal obliques. It sometimes is referred to as the girdle muscle as it wraps around transversely. Connected to our illiac crest (pubic area) and the cartilage of the lower ribs it does look like a girdle. With this large muscle having fibers running transversely it is a key component of the core. No joints being crossed.
The rectus abdominis originates at the pubis and inserts on the 5-7th costal cartilages (ribs), and on the xiphoid process of the sternum. No joints being crossed.
So here we have 2 muscle groups that don’t cross any joints in our body. How do we contract the muscles if they don’t cross a joint? Think of that when doing exercises such as leg raises. If the motion of raising and lowering our legs does not cause the concentric or eccentric contraction of our core muscles because those muscles are not connected to our femur (upper leg) bone then how is this an exercise for the core?
This is where it’s up to you. These abdominal muscles will play a stabilizer role in this exercise helping you to keep you core stable as you keep your back on the floor. But, you have to actively think of this, you have to focus on these core muscles engaging and stabilizing your body, your core. What also helps with this is using the isometric contraction to contract the muscles.
Isometric contraction is contracting the muscle without lengthening (eccentric contraction) or shortening (concentric contraction). How can you do this with the abs? Think of tightening your abs as if someone was going to punch you in the gut. The muscles are contracting but not lengthening or shortening. You can also do this: Suck in your abs drawing in your lower abdomen below your naval, and hold it. This is referred to as hollowing or vacuuming. You can do this, and isometric contractions anytime; sitting, standing, working, etc. Do this and hold it for 10 – 15 seconds to start, and be sure to continue to breathe. Then increase the time to 30 seconds, or a minute. Be sure to incorporate this into workouts when planking, etc.
Let’s look at some exercises we can do to strengthen these muscles:
- Russian twist: Starting seated with knees together and bent, raise your feet about 6 inches off of the floor and lean back slightly. Twist from side to side keeping your core tight in that vacuum state and as you twist bring both hands over try to touch the ground.
- Plank: Staring laying down on your belly lift your body up onto your elbows and toes. Keep you hips up imagining a line from your shoulders to your ankle and your hips intercepting that line. Keep the belly sucked in actively engaging the transversus abdominis. To add difficulty lift a hand up straight out ahead and to add even more difficulty do the same with a leg lifting the opposite foot off of the ground keeping the leg straight.
- Crunches: If is very important to keep a neutral spine while doing crunches. This means not pulling on your head and curving the spine while crunching. Most people do this because it makes it easier and makes us feel like we are being successful. Doing more of something that can hurt us is not being successful. Keeping your spine in a neutral position put your hands by your ears and look straight up. Now, bending at the hips, contracting your abs, lift your shoulders up off the ground. Now, lower back down but don’t let your shoulders touch the ground! Keeping the load on the abs by not letting your shoulders touch the ground thus eliminating the rest is really hard but this is what will get you a strong transversus abdominis and will help prevent back injuries and will also help in giving you that flat stomach most people are looking for. Technique is key as always
Working muscles that don’t cross a joint is harder as it requires much more concentration and focus since it’s not as easy as moving a limb. YOU HAVE TO ACTIVELY ENGAGE THE MUSCLES BY ISOMETRIC CONTRACTION OR BY HOLLOWING. Not doing these things will result in putting in lots of time but not getting the results you want and need.
This post is just the beginning of building a strong core. My plan is to break it down even further in upcoming posts. But this should get you started and covers enough to give you a strong back supporting core.
And remember, if a muscle does not bridge a joint, bending a joint does not work it directly.
Yours in health,