Spine Stability: Principles of "Core" Training

My interest in "core" stability stems from my profession as a Pilates teacher. Pilates is an artistic approach to exercise and I was taught to look at movement from a qualitative perspective; and while I learned (and am still learning) a lot, I wanted to take a scientific approach towards the method to truly understand what makes it such an effective movement system. With the former statement being one of the major driving forces behind my Masters' project, the second reason I chose to do this is because fitness professionals need to be able to teach exercise in a safe and effective manner. These days there are rarely any "normal and healthy" bodies, which furthers the need to incorporate evidence-based practice in our work. 

Regarding the title, I decided to use core in quotation marks because it is still a nebulous concept and has a number of different meanings amongst individuals of different academic backgrounds. However, researchers seem to believe that the "core" is made up of muscles and tissues that support the spine; it is the idea that if you're "core" is stable, then you're spine is stable while you're body moves around it (McGill, 2007).

Regarding the stability models, the first two models (Bergmark and McGill) look at the stability of a system by observing the potential energy of it. It follows the idea that if the amount of work done on the system is less than the potential energy of the system, the system is stable. One of the major deficits of Bergmark's model is that it is 2-D and does not consider the 6 degrees of freedom (lateral flexion, flexion/extension, and axial rotation) that the spine can perform. McGill's model takes it a step further by developing a 3-D model of the spine based on the understanding that muscle tension has similar physical properties of springs (Porterfield and DeRosa, 1991). Springs are mechanical devices with stored energy and stiffness. Therefore energy from an outside force or perturbation can be instead stored as potential energy (Porterfield and DeRosa, 1991). 

The last three stability models take into consideration the role of motor control in spine stabilization and the division between the local and global system. The role of motor control is to send feedback to the central nervous system and relay information to the muscles on proper timing, recruitment, and tension required for sufficient stability. 

This is a poster presentation of my work thus far. I still have the next three months to complete the literature review and will have that up and ready when it's done! Thank you for reading!

Link to poster: Click here

Note: None of this is my original data. I am performing a systematic review of previously published research and I take no credit for data analysis.

References:

  1. Bergmark, A. (1989) Stability of the lumbar spine. A study in mechanical engineering. Acta Orthop Scan, 60.
  2. McGill, S. (1997) The Biomechanics of Low Back Injury: Implications on Current Practice in Industry and the Clinic. J Biomechanics 30, 465-475.
  3. Panjabi, M. (2003) Clinical spinal instability and low back pain. J Electromyography and Kinesiology, 13, 371-379.
  4. Comerford, M.J. & Mottram, S.L. Functional stability re-training: principles and strategies for managing mechanical dysfunction. Manual Therapy. 6.1 (2001): 3-14. Web. 5 Sept 2014.
  5. McGill, S., Grenier, S., Kavcic, N., & Cholewicki, J. (2003) Coordination of muscle activity to ensure stability of the lumbar spine. J Electromyography & Kinesiology, 13, 353-359.
  6. Porterfield, J. & DeRosa, C. (1991). Mechanical Low Back Pain. Philadelphia, PA: W.B. Saunders Company.
  7. Cook, G. (2007). Movement. Aptos, CA: On Target Publishing.
  8. McGill, S. (2007). Low Back Disorders: evidence-based prevention and rehabilitation (2nd edition). Champaign, IL: Human Kinetics. 
  9. Gardner-Morse, Stokes, & Laible. (1995) Role of muscles in lumbar spine stability in maximum extension efforts. J Orthopaedic Research, 13, 802-808.