Q: What comprises the ‘core’?
The core is a term that is thrown around far too much. Having core strength is not about having strong abdominals or a six-pack. Having core strength is about controlling movements with the correct movement patterns and being able to maintain the correct spinal alignment which is associated with the movement. One of the biggest issues I’ve seen in Women’s health is women who have abdominal muscles that are too tight. If the abdominal wall is too tight it can cause the separation of the abdominal muscles to occur at an earlier stage during pregnancy. A second issue with performing too many heavy loading abdominal exercises is that it often causes splinting and bracing which will load and bear down on the pelvic floor.
Spinal stability (1) is a concept that was derived in the early 1990’s and involves a model describing passive, active and neural control systems. From the model of spinal stability the term core muscles become more widespread but I fear that over time the information has been diluted and distorted. This is what I know and teach about abdominal muscles, mostly commonly called the core.
The ‘core’ is another word for the abdominal wall, which is comprised of the rectus abdominus muscles, internal and external obliques and transversus abdominus. The local muscle system is often thought to comprise of deep muscles which have their origin and insertion directly onto the lumbar vertebra, including lumbar multifidus and transversus abdominis. The global muscle system is therefore made up of the more superficial trunk muscles that cross multiple segments and attach indirectly to the vertebrae through fascial connections such as the thoracolumbar fascia.
If we all switch on our stomach and hold it hard then we become a plank and this deprives the spine of being able to control movement through range. It actually leads to higher compressive loads through the spine. During pregnancy there are increasing loads placed on the spine and pelvic floor associated with a growing tummy. This a normal change associated with pregnancy. Knowing which exercises are safe to complete and how to have the best technique is a great way to take care of your body. Firstly, avoid exercises that place excessive load on the spine and pelvis. Secondly, do the exercises well and know that you’re in control.
The take-away message about abdominal muscles is that stronger isn’t always better. We aren’t meant to walk around and move like planks. The deep stabilising muscles are not consciously driven - they are controlled by spinal feedforward mechanisms based on the way we move. Doing exercises during the day to improve our technique and posture is great but don’t do it all the time. It is just not natural. Having rock hard abs is not the answer when it comes to pregnancy. You need to allow for the stomach to grow. In saying that, you don’t want to have poor technique. During exercises there are some tips for making sure your technique is correct and your posture is in the best position. Let’s take a look at that for a moment.
Q: How do I activate my lower abdominal muscles?
After saying all that about the core I’d still like to discuss how to achieve a safe abdominal contraction. After giving birth it can be hard to find the deeper abdominal muscles with good technique. Particularly after having a caesarian birth, where these muscles are cut during the surgery.
A good visualisation and analogy for the abdominal wall and pelvic floor working together is a can of beans. The roof is the diaphragm, the floor is the pelvic floor and the walls are your abdominal muscles. When you activate the pelvic floor i.e. squeeze and lift the floor and combine this with an abdominal wall contraction, the pressure inside the can will increase. In order to keep a normal pressure with these muscles active, you need to breathe i.e. move the top up and down.
Let's look at a second analogy for activating the lower abdominal muscles...
In lying start by placing your hands on your pelvic bone and let your fingers rest on the soft muscle inside the hip bones. First squeeze and lift your pelvic floor. If you feel the muscles under your finger become very firm and push upwards - that is not activating your pelvic floor, that is engaging your obliques which actually bear down on the pelvic floor. When you activate your pelvic floor correctly you’ll feel a faint drifting and sliding movement under your fingers matching the squeeze and lift movement.
To engage the abdominals think about the muscles that connect the two hips bones below the belly button. Imagine the muscles are drawing together and towards the centre. This inward drawing movement is normally accompanied by a drawing inwards of the belly button. If you notice the top of your abs (near your ribs) tensing and pushing down - this is again not a deep abdominal contraction.
In standing place your hand on your stomach below the belly button. If you’re pregnant, imaging giving your baby a hug with your lower tummy muscles (just gently) and your stomach with lift slightly back off your hand. If you’re not pregnant this technique still works or another visualisation is to imaging doing up a tight pair of pants and gently drawing your tummy backwards to do up the button.
Q: How do I do this during exercise?
- The first tip - breathe. When we breathe in and out our abdominal muscles contract to assist with expiration. So go for a walk with a friend, get a little puffed and sweaty and breathe - just breathing helps to keep the abdominal muscles working.
- Posterior pelvic tilting, the action of tucking your tailbone downwards and bringing the pubic bone upwards is a movement that often is associated with reducing the amount of sway back and is accompanied by engaging of the lower abdominals.
- As mentioned above, place your hand on your stomach below the belly button. Without sucking in the upper abdominals or flaring your ribs, gently draw your tummy away from your hand.
- Activating both the pelvic floor muscles and abdominal muscles is a gentle activation. It will not feel strong like doing a crunch or squat where the muscles activate and become hard. These deeper stabilising muscles are not designed to create movement, they are designed to help prepare the body for movement. They switch on early and hold for long times. You should still be able to breathe normally and talk without losing control. The most common mistake is trying too hard.
1. Richardson, C., Hodges, P., & Hides, J. (2004). Therapeutic exercise for lumbopelvic stabilization: Churchill Livingstone Edinburgh.