What does Core Stability really mean?
Whether you are preparing to hit the ski hills this season, play golf next season, perform fall yard work, or simply are wanting to continue to walk and perform all your household chores with ease and efficiency, it might be helpful to be knowledgeable about the term ‘core’ and how timing of our core contributes to quality of movement whether we are participating in sports or activities of daily living.
The ‘core’ can be interpreted in many ways, depending on who is explaining it. Some leading spine researchers debate that a true ‘core’ even exists (O’Sullivan 2012 interview here). Scientific reviews of high level (level 1) evidence conclude that there is not any one superior exercise for chronic low back pain. The popular belief that core stability exercises are essential to prevent and address back pain is not supported by research (don’t shoot the messenger) (Smith et al 2014). Sure, these exercises may help some people; but not for the reasons we may think. This debate is for another post. That said, we all likely have heard of the ‘inner core’ described as a group of muscles surrounding the trunk and described as a cylinder. The main function of these muscles is said to create spinal stability and control the intra-abdominal pressure (IAP) when the rest of the body is in motion. There are 4 main muscle groups that make up the inner core: Transversus Abdominus (TA), Multifidus (MF), Pelvic Floor muscles (PFM), and the respiratory diaphragm. TA is the deepest abdominal muscle that wraps around your abdomen like a corset, and is connected to tissue surrounding the spine. When TA engages, it assists in increasing the pressure inside the abdomen, which
can be one of many factors that contribute to trunk stability. MF is a deep spinal muscle which makes up the back part of the core. It is a postural muscle that helps keep the spine erect. The PFM’s are the bottom part of the ‘cylinder’ or core. More information about the role of the pelvic floor and the factors that influence its function is here.
The respiratory diaphragm makes up the top part of the cylinder. When all of these muscles engage in a coordinated manner, they help to maintain the pressure in the abdomen which then provides the stability to the spine and pelvis. It is important to note that the timing of these muscle engagements is needed for efficiency of movement and function, which is why I often like to refer to this phenomenon as “core timing” instead of “core stability.” For optimal core function, these muscles will activate in a sophisticated and coordinated during movement and are ideally engaging at a variety of intensities, automatically, throughout all movement, all day! Julie Wiebe, PT, describes the core strategy system as ‘piston science.’ Antony Lo, PT, discusses the refined recruitment that continually changes in response to each task as “tension to task.”
A common misconception is that “strong abdominals protect the spine”. In fact, as described above, the abdominal muscles make up only one part of the core. Furthermore, coordinated ‘timing’ of the engagement of the TA is important and not just the mere ‘strength’. The famous “6-pack” or Rectus Abdominus muscle that many fitness fanatics train is not the muscle we are trying to target here. Instead of engaging TA adequately, you may be using or over-recruiting the Rectus Abdominus (as evident by the abdominals popping out and up) to compensate for the TA that may not be recruiting appropriately.
Core timing or core training can play an important role in any rehabilitation program. A healthy core means a healthy foundation from which our limbs can move with more power and efficiency. However, can we actually volitionally ‘train’ each muscle to engage in a perfectly timed and refined way? It’s quite a sophisticated and automated system: there is debate on whether or not we can actually cue the timing of the core adequately. That is also for another post!
For now, I will say that in my clinical experience, cueing breath and ease of movement seems to improve core timing (therefore movement efficiency and performance) more than actually cueing TA, PFM’s or MF to voluntarily ‘engage.’
Brent Anderson, PT, PhD, explains a similar approach, and uses two real-time ultrasounds to illustrate this concept here.
Core timing can be an essential part of any regular workout routine. Whether you enjoy recreational sports, competitive sports, pilates, yoga, or enjoy working out at the gym, addressing your core (through breath) can improve your abilities and enhance your overall performance.
If you experience low back pain, then a visit to your physiotherapist or other trained health care professional would be a good idea. See “Truth About Back Pain” for more info on myths vs truths about back pain and the myth of core stability here.
**This article is not intended to act as medical advice, nor to diagnose or replace your current treatment. Please seek clearance and guidance from your licensed healthcare professional prior to participating in any of the tips, advice, practices or movements mentioned in this article.
By Shelly Prosko, PT, PYT, CPI, Blissology 200-hr YTT graduate
Check out Shelly’s teacher profile to learn more.