New Study from Dr. Stuart McGill’s Biomechanics Laboratory at the University o
f Waterloo
As many of our patients know, we favor research based exercise and rehabilitation at our clinics. For many types of low back pain, spinal stabilization exercises are very commonly used. For patients with back trouble, the back’s load bearing capacity is often diminished so that many commonly prescribed exercises can excessively load the back and are usually inappropriate.
One of the exercise protocols we use for improving spinal stability while minimizing excessive loading is based upon research out of Dr. Stuart McGill’s laboratory at the
Dr. McGill’s publishes exceptional papers more often than some people change underwear. But we found the recent article published this year in the Archives of Physical Rehabilitation titled “Exercises for spine stabilization: Motion/motor patterns, stability progressions, and clinical technique” especially relevant for patients and clinicians.
The article investigates three well researched and commonly used spine sparing exercises that are used in our clinics for spinal stabilization. Three exercises and their progressions were studied: (1) curl-up (2) side bridge, and (3) bird-dog (the “Big 3”). With these exercise, they studied muscle activation, 3D spinal mechanics and the effect of theclinician offering corrective input during exercise.
While I rarely see anybody doing the neutral crunch at the gym I do occasionally see the side bridge and bird dog. However when performed, they are usually done too fast and without the control, neutral spine posture, or attention to muscle co-contraction that is talked about in McGill’s methodology.
One of the co-contraction techniques widely used is an‘abdominal brace” where the patient contacts the abdominal muscles like they are bracing for a abdominal muscles like they are bracing for apunch. Not pushing the belly out or sucking the belly in. Dr. Mcgill’s research showed that raising the elbows off the floor during the neutral curl up increased rectus abdominis activity. Co-contraction with an abdominal brace during the neutral curl up increased the internal and external oblique to 30% of maximal voluntary contraction.
The studies involving the side plank exercise showed clear progression in muscle activation from ½ bridge to full bridge (with legs straight) with the most muscular challenge moving from side bridge to plank resulting in muscle challenge of 50% of maximal voluntary contraction in the rectus, abdominis internal and external obliques.
The bird dog progression was from the all fours position to just arm, then just leg and then both arm and leg, using abdominal bracing and then abducting the arm slightly. The study again showed a clear progression of muscle activation through the progression of the exercises.
When evaluating clinical guidance, factors such as addressing patient asymmetries and applying fascial raking (using firm fingers pressure on the abdominal musculature to add feedback and better activation) were assessed. The fascial raking resulted in increased oblique muscle activation and decreased rectus abdominis activation, therefore improving the neutral spine posture. It was also especially useful in decreasing the amount of twisting (or uncoupling) of the torso during the plank to side bridge.
Although we currently use employ feedback on abdominal bracing and clinical corrections for asymmetry during the exercises, strive for neutral posture and promote abdominal bracing, we have not used the abdominal fascial raking to any large extent. Given the findings of this study, I think patients should expect to start seeing our practitioners digging their fingers in some abdominal musculature during stability exercises.
Mark Pitcher DC, Msc
chiropractor, exercise physiologist
For additional information read Dr. McGill’s Books:
Low Back Disorders and Ultimate Back Fitness
Visit www.backfitpro.com for more information.
