The Science Behind The Big Three


Professor McGill examined over years, all of the “so called” common sense recommendations for the best exercises to do if you have persistent low back pain.

However, most of these recommendations that he came across were not found to be beneficial at all, even though they sounded as though they might be!

For example

  1. When you lift you should bend your knees and keep your back straight;
  2. If you do sit ups, bend your knees and keep your back straight.
  3. If you increase the flexibility of your low back it will reduce back pain.

Do any of these sound familiar? I’m sure they do!

However, the truth is that scientific evidence shows that on average,

 Those who have more range of motion in their backs have a greater risk of

 future troubles.

So you are not helping yourself at all by doing those lovely stretches that feel good and ‘they say’ ARE good for helping with low back pain. You need to know the balance between stability and mobility that YOU need and this may shift during a progressive exercise program as symptoms resolve, or with advancing age, or as rehab/training objectives change.


Another generally perceived goal of training the back is to increase strength

           and that you should use the   “no pain no gain” philosophy.


Strength has little association with low back health, in fact, many hurt their backs in an attempt to increase strength. Research has been carried out on the military who have had to undergo many sit ups daily in attempt to be ‘superfit’ only to find that a lot of these people trying to increase their fitness actually damage their back in the process.


Performing situps both replicates a potent injury mechanism (specifically posterior disc herniation) and results in high loads on the spine.


On the other hand, muscle endurance, as opposed to strength, has been shown to be protective for future troubles and for most of us it is better to train for stability rather than stretching to increase range of motion.


Recent investigations into injury mechanisms have revealed that many back training

practices actually replicate the loads and motions that cause the parts of the low back to become injured.


For example, disc herniations or ‘slipped discs’ need not have excessive loading on the back to occur, rather repeated forward flexion motion of the spine is a more potent mechanism.


Thus, if full flexion or deviation is avoided in the spine, the risk of herniation is remote.


You injure your low back by damaging the supporting tissues. This damage reduces the normal stiffness in the spine resulting in unstable joints. Thus, while injury results in joint instability, an event characterized by improper muscle activation can cause the spine to buckle, or become unstable.


Hence I advocate doing the Big Three as shown last week – if you have no time or just don’t enjoy exercising – do what I do. Put on some music – set your watch for 15 minutes and do the Big Three for that time, carefully and thinking about what you are trying to achieve. Five minutes of each will feel like a long time when you first start but as you feel better and stronger, you will probably end up by doing 10 minutes of each exercise and you hold the positions for longer or make the surface on which you exercise less stable in order to challenge the muscles more … and just imagine how much better your back will be able to withstand irritation when it is so much more STABLE.


There is no question that instability at low loads is a BIG problem. For example, it is possible to damage the passive tissues of the back while bending down and picking up a pencil, or sneezing, but only


                         If sufficient stability is not maintained.


McGill’s Big Three are all about STABILITY and how to achieve it safely.


The Big Three as I explained last week are based on the latest scientific knowledge of how the spine works, and becomes injured.


In addition, they have been quantified for spine load, resultant spine stability, and muscle oxygenation.


Your goal is to enhance spine stability through grooving motion and muscle activation patterns to prepare for all types of challenges.


Of course, other exercises may be required subsequently to enhance daily functioning, but once again, these will depend upon what you DO daily in your job or in spare time.


Too many patients are rehabilitated using athletic philosophies, or worse yet “body building” approaches. We do not encourage this at the Avenue Clinic. We use these exercises frequently as a basis for rehabilitation when you have low back pain, and we adhere to the evidence provided by Professor McGill because


McGill’s emphasis is on enhancing spine health


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.
  1. The no pain no gain axiom does not apply when exercising the low back, in fact I would say that just the opposite is true
  1. While these exercises are excellent for low back pain recovery and prevention, you should also do some general exercise such as walking. Adding cardiovascular exercise to the Big Three has been shown to be more effective in both rehabilitation and for injury prevention.
  2. Diurnal variation in the fluid level of the intervertebral discs (discs are more hydrated early in the morning after rising from  bed), changes the stresses on the disc throughout the day. Specifically, they are highest following bedrest and diminish over the subsequent few hours. It would be very unwise to perform full range spine motion while under load, shortly after rising from bed.
  3. Given that endurance has more protective value than strength, strength gains should not be overemphasized at the expense of endurance.
  4. There is no such thing as an ideal set of exercises for all individuals… check with your chiropractor before you start that you are doing the best ones for your particular problem.
  5. Be patient and stick with the program. Increased function and reduction in pain may not occur for 3 months.


References for these exercises:


Burton, A.K. (1997) Spine Update: Back injury and work loss. Biomechanical and psychosocial influences. Spine22: 2575-2580.

Callaghan, J.P., Gunning, J.L., McGill, S.M. (1998). Relationship between lumbar spine load and muscle activity during extensor exercises.

Physical Therapy78(1): 8-18

Callaghan, J.P., Patla, A.E., and McGill, S.M. (1999) Low back three dimensional joint forces, kinematics and kinetics during walking.

Clin. Biomech.14: 203-216.

Callaghan, J.P., and McGill, S.M. (2001) Intervertebral disc herniation: Studies on a porcine model exposed to highly repetitive flexion/extension motion with compressive force. Clin. Biom.16(1): 28-37.

Cholewicki, J., McGill, S.M. (1996)

Mechanical stability of the in vivo lumbar spine: Implications for injury and chronic low back pain.

Clin. Biomech 11(1): 1-15.-226.

Hodges, P.W., Richardson, C.A. (1996) Inefficient muscular stabilization of the lumbar spine associated with low back pain. Spine21: 2640

McGill, S.M., Sharratt, M.T., Seguin, J.P. (1995) Loads on spinal tissues during simultaneous lifting and ventilatory challenge.

Ergonomics38: 1772-1792.

McGill, S.M. (1997) The biomechanics of low back injury: Implications on current practice in industry and the clinic. J. Biomech.30: 465-475.

McGill, S.M., Childs,A. Liebenson, C. (1999) Endurance times for stabilization exercises: Clinical targets for testing and training from a normal database.

Arch. Phys. Med. Rehab.80: 941-Physical Therap78(7): 754-765.

McGill, S.M., and Cholewicki, J. (2001) Biomechanical basis for stability: An explanation to enhance clinical ability. J. Orthop. Sports Phys. Ther.31(2): 96