Scientific Evidence For The Russian Kettlebell In "Fixing Bad Backs"

Steve McNamara Physical Therapist

February 24, 2006 05:18 PM

Anyone who has become a kettlebell devotee is aware of the testimonials purporting that training with the device "fixes bad backs". Others have had direct experience with this claim. This article will explore specifically how the kettlebell accomplishes this from an evidence-based, scientific standpoint.

As an RKC, physical therapist and personal trainer I am specifically implementing variations of Jeff Martone's H2H (hand-to-hand) drills for client low back rehabilitation. My discussion here focuses primarily on H2H drills and then briefly detail how the basic kettlebell drills can benefit low back pain in general. After some discussion of low back anatomy and associated muscle pathology, I will describe some of these exercises and their effects.

It is helpful for an RKC to have a rudimentary understanding of the concept of lumbar segmental stabilization. A segment is two vertebral bodies and all the structures in between including the discs and the facet joints. Segmental stability means, by definition, that there is no abnormal displacement of one vertebra on the other. An oft-used analogy is that of stacked children's building blocks with perfect alignment. Proper segmental stability is the ability of each block to resist "displacement" during movement of the whole unit.

Punjabi's model of stability is a three-tiered system (1). This includes the passive subsystem (osteoligamentous structures), the active subsystem (muscles) and the control subsystem (nervous system). This model allows that if there is a deficit in one system that the other two systems can compensate to maintain a degree of stability. If the capacities of theses systems are exceeded, then segmental "instability" is the result and this yields small micro movements of the vertebrae in relation to each other.

What does all this mean? Essentially, segmental instability leads to low back pain. It is these small, abnormal micro movements that lead to what Kirkaldy-Willis terms the "degenerative cascade". This includes wear and tear on the discs, vertebral end plates and the facet joints.

A group of Australian physical therapists, the Queensland Group, has been able to identify specific patterns of muscle inhibition (weakness) associated with low back pain (2).

The Transverse Abdominis, Lumbar Multifidus and Consequences of Low Back Pain

The Transverse Abdominis (TrA), the deepest of the abdominals is considered a stabilizer of the spine by virtue of its attachment to the transverse processes of the lumbar vertebrae, along with the internal oblique and the latissimus dorsi via the lumbodorsal fascia. It provides stability through a mild compressive effect and by providing rigidity in the coronal plane. The TrA is also involved in end phase exhalation (an indication for Pavel's power breathing in promoting lumbar stability).

The Queensland Group discovered that in normal spines the TrA actually contracted to stabilize the spine prior to an individual simply raising an arm (2). This is anticipatory control. In patients with low back dysfunction, anticipatory control is disrupted and the TrA exhibits delayed or altered firing. This suggests then that patients had a propensity toward lumbar segmental instability.

Further, they did real time ultrasound imaging of the Lumbar Multifidus (MF) muscle (3). The lumbar multifidus muscles are short, local muscles of the spine. They are located midline and deep in the lumbar region comprising the bulk of the "meat" in the lower lumbar region. This important muscle unit has multiple functions but its role in segmental stability can be thought of as a vertebrae pulling back onto it.

The ultrasound imaging revealed that within one week of acute onset low back pain that the lumbar multifidus lost cross sectional area by 25% on the painful side (3). When asymptomatic subjects from the originally painful group were re-imaged at follow-up they did not necessarily recover the muscle fullness. Because of the function of the MF in segmental stability, this finding indicated that early insult to the low back could result in problems in resisting the abnormal micro movements discussed above.

Specific Training Reduces Low Back Dysfunction

The encouraging discovery of the Queensland Group is that specifically training the TrA and MF results in decreased low back pain and much less likelihood of re-injury and patients seeking follow-up medical care (2).

Simply put? "Muscle control = pain control". This is where the kettlebell comes in powerfully.

Specifically training meant facilitating a co-contraction of the TrA and MF. Some of their work was misinterpreted to mean that performing abdominal hollowing ultimately increased low back stability. Stuart McGill, PhD, a Canadian biomechanist, has shown that this is not the case and that abdominal bracing is preferable to hollowing (4). However, the advice to "pull your navel in toward your spine" is common advice dispensed by personal trainers and physical therapists. Pavel Tsatsouline has also confronted this issue in From Russia with Tough Love.

Kettlebell lifters are taught to brace, not hollow. They use "Power Breathing" and "Paradox Breathing" for developing abdominal muscle recruitment. The effort is to create a "virtual belt" of stability for the lumbar spine. These techniques, detailed below, are in line with some of McGill's research in which he found that individuals who are poor back stabilizers tend to cycle their abdominal muscle contractions with the breath cycle; typically losing abdominal muscle tension and therefore stability on the exhale.

In Paradox Breathing, the abdominal muscles are tensed against the descending diaphragm during inhalation. As the diaphragm descends, it wants to displace the internal organs causing the typical bulging of the belly in breathing. Paradox Breathing develops instantaneous abdominal muscle tension with the inhale.

This abdominal muscle tension is maintained and then intensified during exhalation in Power Breathing. The abdominal muscle contraction, the "bracing" sort, is never lost during the breath cycle. Therefore, low back stability is facilitated. Pavel Tsatsouline details this technique in From Russia With Tough Love and elsewhere. All beginning kettlebell trainees learn this important breathing technique during the kettlebell swing.

Another physical therapist, Alec Kay in Alaska, did his dissertation on the MF (6,7). He intensely reviewed the literature regarding the anatomy and function of the MF. Mr. Kay concluded that the best exercise for the MF is "rotation on an unstable surface" (5). Here is the indication for kettlebell H2H drills in managing low back pain. Watch Jeff Martone demonstrate H2H exercises. Evaluate what is occurring in the trunk during around the body passing, upper cuts, tactical lunge etc. Rotation! Transverse plane movement! These movements powerfully yet safely recruit the MF.

I am particularly fond of "helicopters" as the movement is produced in a diagonal upper extremity and trunk pattern. The kettlebell moves horizontally on a vertical axis (transverse plane) during the pull-push-release. There is another rotation moment when you catch the kettlebell and I would bet that this is where there is intense activation of the MF. An EMG study could likely confirm this.

To further the effect of H2H drills attempt to perform the training on an unstable surface. I recommend Gray Cook's Reebok Core Trainer. Dyna-discs, Bosu and other unstable surfaces can be too unstable rendering the drills impossible for most folks.

Obviously, H2H drills are for more advanced and coordinated clients but the exercises are a load o' fun. The fun and the novelty of the kettlebell are similar to what Doug Kelsey, PhD; PT has called the 3rd Gravitating Body in rehabilitation. The 3rd Gravitating Body is anything introduced into a system to help overcome the predictable.

The kettlebell beats the drudgery of conventional low back rehabilitation, typically floor or mat exercises and machinery. Hence, H2H kettlebell training is a 3rd Gravitating Body of low back rehabilitation. For more on this concept read Doug Kelsey's essay.

Additional Evidence

This article took a narrow look at a single application (H2H drills) of the kettlebell in low rehabilitation. There is further evidence of the efficacy of the kettlebell in treating low back pain. Specifically, this includes developing endurance of the lumbar extensors.

McGill cites research that suggests a correlation between diminished back extensor endurance and low back troubles (8). He concludes that the lesson for exercise prescription is that programs that emphasize extensor endurance are better than outright extensor strengthening exercises (8). Pavel Tsatsouline has advocated this as a specific benefit of kettlebell swings and snatches.

Vladimir Janda, a renowned Czech MD, for decades expounded on the concept of gluteal inhibition as a common muscle pattern exhibited in people with low back dysfunction. He found that this was associated with shortened and hypertonic hip flexors. This phenomenon is observable in the veteran population that I work with as a physical therapist. The gluteal contours of these individuals are flat; they have no butts! Again, the kettlebell comes to the rescue. Swings with emphasis on "rooting" the feet and a "static stomp" powerfully recruit the gluteals and improve hip extension.

So, there you have it. Scientific proof that kettlebells "fix bad backs".

Now, you must be aware that this type of training is not appropriate for clients or patients with acute, severe and irritable symptoms. This type of training comes in at the chronic or stable stage in a client's recovery. A typical client will require some sessions of kettlebell basics prior to commencing H2H.

I do not mean to give short change to the basics. The swing and other basics are also tremendous training for the low back. There is nothing like high repetition swings for developing the back extensor muscles. I focus on H2H as a way of making low back rehabilitation super dynamic. Also, most clients performing H2H drills should start with the 18 lb. kettlebell and would rarely need to progress beyond the 26 pounder. You really have to be sensitive to load with the low back injured. However, eventually as the client gains function and decrease pain, the other traditional KB exercises can be pursued with heavier loads to challenge the stabilizing mechanism.

It is valuable for RKCs to be armed with evidence-based information to provide to a skeptical fitness consumer or possible medical referral source. I would encourage RKCs to be able to articulate the science discussed in this article in language that is appropriate to their target audience. You may have to "gravitate down" in how you explain these concepts. You may contact me with any questions regarding this article at stevemcnamarapt@yahoo.com.


About the Author

Steve McNamara, PT, RKC, CPT is employed part-time as physical therapist by the Salt Lake City VA Healthcare System. His duties include acting as a Clinic Attending and Clinical Instructor in a nationally recognized physical therapy student intern program. He spends the rest of his time as a personal trainer and spreading the joy of kettlebell training. Mr. McNamara was a Certified Strength and Conditioning Specialist through the National Strength and Conditioning Association in the early 1990s. He was a partner in a private physical therapy practice from 1991 to 1999.


References


1. Panjabi M, Abumi K, Duranceau J, Oxland T 1989 Spinal Stability and Intersegmental Muscle Forces: A Biomechanical Model. Spine 14 (2): 194-200

2. Richardson C, Jull GA, Hodges P, Hides J Therapeutic Exercise for Lumbar Segmental Stabilization in Low Back Pain ? Scientific Basis and Clinical Approach 1998

3. Hides JA, Stokes MJ, Saide M, Jull GA Evidence of Lumbar Multifidus Wasting Ipsilateral to Symptoms in Patients with Acute/SubAcute Low Back Pain Spine Vol. 19, No. 2, pp 165-172

4. McGill Stuart Low Back Disorders Evidence Based Prevention and Rehabilitation 2002, pp 210-211


5. Kay Alec, PT, DMT, ATC, FAAOMPT The Lumbar Multifidus: The Good, The Bad and the Ugly December 15, 2001 Coursebook University of Utah

6. Kay Alec An Extensive Literature Review of the Lumbar Multifidus: Anatomy The Journal of Manual and Manipulative Therapy Vol. 8 No. 3 (2000), 102-114


7. Kay Alec An Extensive Literature Review of the Lumbar Multifidus: Biomechanics The Journal of Manual and Manipulative Therapy Vol. 9 No. 1 (2001), 17-39

8. McGill Stuart Low Back Disorders Evidence Based Prevention and Rehabilitation 2002, pp 218

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