The Science Behind Tighten the Core


To better understand the Core Activator, we need to understand a little about the spine.  The lumbar spine (a/k/a low back) is comprised of 5 vertebrae.  Each vertebra has a disc above and below it and 2 facet joints posterior or towards the back of the spine.  The facet joints are synovial joints very similar to our knuckles.  The disc in front and the 2 facets in back have the spinal cord between them.


The facets – If a person leans back, they place a greater load on the facet joints.  If a person leans forward, it places less of a load on the facet surfaces, but it increases a tensile load on the ligament that encapsulates the facets and loads the disc.  To stay healthy, the facet joints need to move.  Subtle motion allows waste products to move out and nutrients in to the facets.  The joint surfaces (articular cartilage) then has nutrition that bathes them.  Loading and unloading the disc is actually healthy for the disc as long as shear forces are eliminated while loading or compressing.


Three types of back muscles that help the spine function are extensors, flexors and obliques.

  • The extensor muscles (back and gluteal) are attached to the posterior (back) of the spine and enable standing and lifting objects. These muscles include the large paired muscles in the lower back (erector spinae), which help hold up the spine, and gluteal muscles.
  • The flexor muscles (abdominal and iliopsoas muscles) are attached to the anterior (front) of the spine (which includes the abdominal muscles) and enable flexing, bending forward, lifting, and arching the lower back.
  • The oblique muscles (paraspinal, rotators) are attached to the sides of the spine and help rotate the spine and maintain proper posture and spinal curvature.

Now that we have covered some of the anatomy of the lumbar spine and some of the biomechanical features, let’s look at why sitting and exercising is not the best – common is not necessarily good.

Sitting Deactivates Core Muscles:  Scientific Research studies show that by sitting we not only increase the load of our disc significantly but we inhibit the activation and neurological firing of the transverse abdominus and internal obliques. According to research presented in the European Journal of Applied Physiology, core muscle activation is limited while performed in a seated position (*Muscle activity of the core during bilateral, unilateral, seated and standing resistance exercise  Results showed the rectus abdominus: 81% lower in bilateral seated vs. standing.

Sitting places unwanted and damaging compression loads on the spine.  Sitting increases the load on the disc up to 1.8 times body weight.  Forward flexion further loads the disc up to 360% at 30°. Compressing the spine while moving creates a shearing of the discs that can become problematic over time, even causing herniation.


Having a flexible spine is not protective, in fact it is quite the opposite according to Dr. Stuart McGill.  “Muscles of the spine/core/torso are designed to stop movement.  Having a very strong back is not preventative for back injury, what turns out to be important is the endurance.” Dr. McGill notes that sucking in your belly to work your core is a myth.  “This idea of drawing in your belly to active the transverse abdominis when performing exercise is highly problematic, you need to stiffen the abdominal wall.”

True spine stability is achieved with a “balanced” stiffening from the entire musculature including the rectus abdominis and the abdominal wall, quadratus lumborum, latissimus dorsi and the back extensors of longissimus, ilioicostalis and multifidus. Focusing on a single muscle generally does not enhance stability but creates patterns that when quantified result in less stability. It is impossible to train muscles such as transverse abdominis or multifidus in isolation – people cannot activate just these muscles. (McGill, 2009)

People with low back pain find it difficult to engage core muscles without repetitive help.  Low back pain subjects failed to recruit transverse abdominus or internal obliques with fast or intermediate limb movement. Hodges, PhD.  Arch. of Physical Med. Rehab. 1999   Muscular strength of trunk is LESS influential in low back pain than co-activation and recruitment patterns.  O’Sullivan, PhD.  JMPT 1997; 5 (1):20-26   

Caveats for Exercise 1. While there is a common belief among some experts that exercise sessions should be performed at least 3 times per week, it appears low back exercises have the most beneficial effect when performed daily. 2. The no pain-no gain axiom does not apply when exercising the low back in pained individuals particularly when applied to weight training, and scientific and clinical wisdom would suggest the opposite is true. 3. While specific low back exercises have been rationalized in this guide, general exercise programs that also combine cardiovascular components (like walking) have been shown to be more effective in both rehabilitation and for injury prevention. Regarding low back; muscle endurance, as opposed to strength, has been shown to be protective for future troubles (snippet from McGill)  

The Journal of Orthopedic Sports and Physical Therapy 2008; 38(3):101-108 Carolyn Richardson PhD , Julie Hyde PhD.  Conclusion of the study: The multifidus muscle atrophy can exist in highly active elite athletes with low back pain. Specific retraining resulted in improvement in the multifidus muscle cross-sectional area and this coincided with decreased pain. The stabilization program involved voluntary contraction of the multifidus, transversus abdominis, and pelvic floor muscles.  (Note- Same muscles involved in abdominal bracing).

Effects of pelvic stabilization on lumbar muscle activity during dynamic exercise:  This study demonstrates that pelvic stabilization enhances lumbar muscle recruitment during dynamic exercise on machines. Exercise specialists can use these data when designing exercise programs to develop low back strength.  Department of Exercise and Nutritional Sciences, San Diego State University, San Diego, California, USA.

Concept of neural plasticity:  Neuroplasticity is your brain’s ability to create new neural pathways and reshape existing ones.  While holding an abdominal brace and performing repetitions we are grooving a neurological pattern.  As we activate core muscles, we exercise an appropriate neurological pathway. The more we exercise that pathway the more efficient that pathway becomes.


While abdominal bracing, you are simultaneously co-activating multiple layers of core muscles.  This means the entire abdominal wall is activated from all angles, sides, and directions, causing the three layers of the muscles to actually physically bind together.  Abdominal bracing of the muscle belt all around our spine includes, but not limited to rectus abdominis, transverse abdominis, internal obliques, external obliques, quadratus lumborum, multifidi.  A functional abdominal brace requires all these muscles to be activated to stabilize the spine and minimize any shear of the disc.  When these core muscles are in poor condition, additional stress is applied to the spine as it supports the body, and back injury or back pain is more likely. Multifidi, external and internal obliques, rectus abdominis were found to activate in all ranges of motion with abdominal bracing on the Core Activator.

SO HOW DOES IT WORK?  The Core Activator places the user in a biomechanically safer and more efficient, spine neutral position.  Since your core muscles have three-dimensional depth and functional movement in all three planes of motion we designed the Core Activator to allow you to train on multiple planes and vectors.  The angle of the Core Activator takes SIGNIFICANT compression loads off the spine, and causes you to utilize the deeper stabilizing muscles of your core.  Your core muscle belt, 360° around your spine, activates together which increases power, stamina, and caloric burn.

EMG tests show the entire core muscle belt, 360° around the spine is activating at the same time.  THIS MACHINE HELPS YOU BURN MORE CALORIES AND GAIN STRENGTH FASTER BECAUSE YOU ARE RECRUITING MORE MUSCLES.


Dr. Jeff’s credentials: click on to enlarge


Research Sources:

1  National Institute of Neurological Disorders and Stroke:

2  Rainville, MD, et al.  Exercise as a treatment for chronic low back pain. Spine J; 2004, 4(1): 106-15. 

3  Liddle, SD et al.  Exercise and chronic low back pain: what works? Pain; 2004 107(1-2): 176-90.

4  Danneels LA et al. CT imaging of trunk muscles in CLBP Pts & healthy control subjects. Eur Spine J 2000; 9:266-72.

5  Mooney, V. MD. How to have a health back, 2003.

6  Solomonow, PhD, MD et al. Spine 1998; 23 (23): 2552-2562.

7  Mooney, Vert, MD.; 2001 & 2003.

8  Mooney, MD. J Musculoskeletal Medicine 1995; Oct: 33-39.

9  Dickenson A., Bennett K: Clin Sports Med. Vol. 4, No. 3, July 1985. Chiropractic Rehabilitation Vol. 1, p. 41.

10 Keller, MD, et al.  Trunk Muscle Strength, Cross-sectional Area, and Density in Patients w CLBP Randomized to Lumber

   Fusion or    Cognitive Intervention and Exercises.  Spine; 2004 29(1): 3-8.

11 Adams Hutton WC Gradual Disc Prolapse, Spine 1985; 10:524-531.

12  Callahan J., McGill SM, Intervertebral Disc Herniations, Clinical Biomechanics 2001: 16(1) 28-37.

     Callahan and McGill have been able to consistently produce disc herniations by mimicking spine motion and load patterns seen in workers and in replicating the motion and loads of some lumbar extension exercise machines (12, 13 ).

13 Liebenson C.,Rehabilitation of the Spine, 2nd edition pp.96-97

14 Carpenter N., Low back strengthening , Med. Sci. Sports Exercise,1999;31(1):18-24

15 Lee J.H.,et al., Incidence of Low Back Pain, 5 yr study. JNMS 1999;7(3):97-101

16 Takahashi I., Mechanical Load on the Disc. Spine 2006:31 :18-23.

17 Vuori I.M.,Physical Activity and Low Back Pain,O.A., Med. Sci. Sport and Exercise. 2001:33:S55-S586

18 Christensen K., Chiropractic Rehabilitation. Vol.1 p.41

19 Liebenson C.,Rehabilitation of the Spine. 2nd edition pp15-16

20 Leibenson C., Rehabilitation of the Spine. 2nd edition .pp300-301

21 Solomonow M. et al., Biomechanics…Low Back disorder. Spine 2003:28:1235-1248

22.Liebenson C., Rehabilitation of the Spine. 2nd edition.  pp303-305

23 Slosberg, Dr. Malik, Review of Literature, Ref. 1-8, 14-17.

24 National Committee for Quality Assurance;

25 Wall Street Journal, May 16, 2007 (Personal Journal; D1) ‘Better Ways to Treat Back Pain’