Please visit: “The Truth About Back Pain” for more updated information and citations as they relate to ‘core stability’ and back pain.
**Edits to this post were made on May 31, 2017 regarding new information and knowledge I have accumulated since this post was written in 2011.**
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.” Read more