Where do you think your core is?
Your answer probably lands somewhere around your abdominal muscles, perhaps towards the lower end. Don’t worry if your answer isn’t specific, because between physicians, trainers and even amongst physiotherapists, your “core” can mean very different things.
That’s why when someone visits us complaining of a “weak core”, we need to examine them closely to find what they mean.
At WLP, when we refer to the core we’re talking specifically about the deep muscles in your abdomen, which are not visible on a surface level and are difficult to isolate during exercise – which makes them very easy to overlook if you don’t know what you’re doing.
The deep muscles are the transverse abdominal, which wraps across your belly from rib cage to pelvis; the multifidus muscle, which lines either side of your spine; the pelvic floor, which forms a bowl like structure beneath your pelvis; and the psoas major, a long muscle that connects the lower spine to the pelvis and thigh.
What Does the Core Do?
Research has been able to show the exact sequence in which muscles activate and how they depend on each other. Here’s a rough outline on how your abdominal muscles are structured:
• Deep muscles (the core)
Your deep muscles aren’t responsible for movement and thus generate very little force. However, they’re also fatigue resistant, meaning they won’t get tired even if they’re activated for extended periods, making their slight but consistent contraction vital for maintaining proper posture.
• Stabilising muscles
Above your core is a layer of muscles that provide stability during movement. They aren’t as fatigue resistant as the deep muscles, so while both layers provide stability, this layer of muscles are most active while a joint is in motion.
• Global muscles
These are the big muscles that get all the attention, such as the rectus adbominis (six pack) and glute maximus. These muscles generate massive amounts of force to cause movement along a joint or hold a position but they can’t do so for long without tiring.
Your deep muscles should be activating about half a second before movement, providing extra support for the stabilising and global muscles. If the deep muscles are activating late or not at all, this results in uncoordinated movements and a feeling of weakness during motion – even if the stabilising and global muscles are strong.
A weak core is just as apparent when you’re not moving as when you are. If your deep muscles aren’t providing enough support for your spine when you’re sitting all day, your other muscle groups will take over. The problem is, these bigger muscles aren’t fatigue resistant, so they spasm and tire over time, causing pain. It’s this imbalance is often what causes lower back pain.
A lack of core activation can even to lead muscle dysfunction. Bigger muscles require more signals from the brain to stay activated, diverting attention away from the deep muscles that should be doing the work to keep you upright. Eventually, the deep muscles can turn off completely. If this goes uncorrected for a few weeks, then muscle wasting will set in.
Why Crunches Won’t Help
The mistake people make when trying to get a “strong core” is they do exercises that put a lot of force through their abdominal muscles, such as crunches. This is great for training your global muscles but does nothing at all for your deep muscles, which actually turn off when overloaded. That means that even if you have a rock hard six pack, the muscles beneath might still be weak.
To rehabilitate someone with a weak core, first we need to make sure they can activate it from a relaxed position, which can be hard to figure out yourself as you need press firmly at specific points on the abdomen to detect if the deep muscles have contracted.
When you’ve learned how to isolate your deep muscles, we prescribe exercises that will gradually increase load on the core without diverting it to your other abdominal muscles, such as keeping your spine neutral while you exercise the joints around it with lunges and squats, or targeting the core directly with rotational exercises such as cable twists.
Once your core is strengthened, just about everything becomes easier to do with less pain, whether you’re sitting or running or playing tennis. A strong core provides the solid foundation that allows all your other muscles to focus on what they do best.
If you have any questions about your core, feel free to get in touch by emailing kam@westlondonphysio.co.uk or calling 0207 937 1628.
Kam Sowman BSc (Physio) MCSP MHCP
Musculoskeletal and Sports Physiotherapist
For any other questions regarding this topic please do not hesitate to contact me at West London Physio on 0207 937 1628 or email kam@westlondonphysio.co.uk
