What is core stability?
"Core strengthening or stability" is a term most people are familiar with, but may not properly understand. Out of interest while I thought about this post, I asked my husband what he understood the term to mean (he works in the digital advertising world and his understanding of muscles and movement would be fairly indicative of the lay person). His response was "it means strengthening the abdominal muscles to help keep the body rigid".
This unfortunately is the idea most people have when it comes to understanding core stability, and it couldn't be further from the truth. "Core strengthening" has become a bit of a buzzword in recent years and this seems to be the basic explanation pedalled out by trainers and the media.
The concept of core stability is a lot more involved than this idea. Firstly the "core muscles" are believed by many to be the abdominals. I've lost count of the number of patients who tell me that they do core stability exercises as part of their training, and when questioned as to the specific exercises they do, they reply "sit ups".
The inner or deep core muscles actually comprise muscles much deeper than your rectus abdominus - this is your outer abdominal muscle, commonly also known as the ‘six pack muscle.’ While a toned rectus abdominus may look good, its ability to contract has no real bearing on core stability.
There are several main muscles compromising your core: a deep abdominal muscle called the transversus abdominus (TrA); a deep muscle running alongside your spine called multifidus; the pelvic floor muscles and the diaphragm. The TrA actually has attachments into your spinal vertebrae and acts a bit like a corset wrapping around your lower back and abdomen. Complimentary (or outer core muscles) include those that help to stabilise the pelvis and spine, including the obliques, gluteals, hip flexors and spinal muscles.
The true concept of core stability can be a little tricky to get your head around, as it differs considerably to regular strength training in the gym. Most of us are pretty comfortable with the idea that to build muscle bulk or strength, we need to do weight training that involves contraction of a muscle, e.g. doing bicep curls will strengthen and build bulk in our biceps. Core stability is a little different to this, as we’re not actually trying to build bulk in the muscles. Rather the concept is to improve the ability of the muscles to activate and fire in correct patterns, as to help control spinal segmental and limb movement.
The traditional (and more well known) core stability exercises are those that use a ‘bracing’ or hold activation of the lower abdominals, often with a flattening of the low back. Clients are often instructed to ‘pull your belly button in’ and ‘tuck the tailbone under’ causing an inward sucking and bracing action. Typical exercises prescribed are the plank or curl ups. However it is now becoming increasingly understood that this type of exercise, and particularly this bracing action, are not necessarily the best way to improve function. In fact, for many back pain sufferers this type of exercise can actually make your symptoms worse.
Why too much ‘abdominal strengthening’ can cause more harm than good.
The whole concept of core stability is thought to have come about following an Australian study that showed that in back pain sufferers there was a deficiency in the TrA to activate. Rather than the muscle being ‘weak’, what they found was that this muscle didn’t achieve and sustain a low-grade contraction as it is designed to do. However it seems that the message people took home from this study was that a bad back equals week abdominals, and the general consensus in the population is that we fix a bad back by strengthening the abs.
The problem with traditional abdominal strengthening exercises is that they involve a lot of flexing of the lumbar spine (as per in sit ups). If this is the only type of exercise encouraged, we are neglecting the other movements of the spine, notably into extension. Overworking the abdominals into this flexed posture can actually create too much tightness in the core region and lead to a multitude of other issues. In my years of practice I have seen a number of women who have developed stress urinary incontinence from overworked abdominals after years of performing ‘traditional’ core strengthening. Think about it in relation to your normal gym program. Would you spend hours of time devoted to strengthening your biceps, but neglect all the other muscles in your arms? Of course not, and the same idea should apply to core stability.
Core stability is about control of movement, not bracing or rigidity
The core muscles in most people are predominately made up of slow twitch or type 1 muscle fibres. These muscle fibres are fatigue resistance and responsible for postural control. Think of them as your endurance runners. Muscles that produce powerful rapid movements in short bursts have more fast twitch or type 2 muscle fibres. These are typically the outer or big global muscles, like the quadriceps. Think of them as your sprinters.
There is now strong evidence to suggest that the type 1 muscle fibres work on a feed-forward mechanism. What this means is that these muscle fibres contract before movement occurs to provide stabilisation of the spine and pelvis. Any movement away from the midline, such as lifting your leg, triggers this mechanism. In other words as soon as the message to ‘lift your leg’ reaches your brain, your core muscles should activate before you even perform the movement. Clever huh! Studies have found that in individuals with back pain, this mechanism is delayed and there is an incorrect pattern or order in the way the muscles fire.
Basically what we have now learnt is that the core muscles are important in controlling the spine and pelvis in relation to movement of the limbs. What we try to achieve when improving core stability in our patients is not simply a focus on performing a one size fits all approach to strengthening the abdominals, but rather looking at how a person’s muscles are activating in relation to controlling movement. This may vary from person to person, and it is therefore really important to have an assessment with someone who has an in-depth understanding of movement and muscle patterning.
We want our endurance runners to be working at a controlled even pace, so that our sprinters can perform short sharp bursts of activity to the best of their ability. In other words the function of the core muscles is to provide a stable base (i.e. the lumbar spine and pelvis) so that we can perform gross motor movements of the trunk and limbs well. Imagine balancing on a tightrope. The tightrope will move, it will bend and straighten and sway from side to side. But when it's tensioned we can still balance and walk along it. Now take the tension completely away. It's impossible to balance on it now. The spine and pelvis is like the tightrope. It's not supposed to be rigid, it's designed to move. The core and surrounding muscles are like the tension, they provide the support to allow the spine to be stable enough for movement to occur in the body.
How does this relate to riding?
More so than many other sports, core control in riding is paramount. Riding differs to most other sports; in that what the rider appears to be doing (if they’re riding well) is not much at all! This type of rider, who makes it look effortless, will generally have excellent core control. This is because their core muscles are producing a sustained contraction and controlling pelvic, spinal and limb movement.
Think of the rider who appears to flop about in sitting trot or the rider who loses control and falls forward after each jump. These riders will typically have poor control and it shows in how they ride and how their horse performs.
Core stability at Sydney Equestrian Physiotherapy
Our approach to core stability is targeted and specific to the individual. We perform a thorough assessment before starting any exercise program, and continue to supervise and modify the program as required. We don’t take a ‘one size fits all’ approach to our classes or therapy. Our focus is always on the prevention of injury (or further injury), and the overall improvement of function, whether that’s sport specific or general day-to-day activity.
So what is a core stability exercise? Click here to watch a video of a basic core exercise for riders.