design that is individual, targeted to core causes, progressive in its administration, and holistic with an eye on long-term injury prevention. These strategies can be tailored to apply to any patient, rang-ing from those with lifestyle-related back pain to elite athletes striving for optimal performance. As well, they begin with something as seemingly simple as opti-mal back health and safety as their ulti-mate goal. INTERVIEW WITH DR. MCGILL Canadian Chiropractor: You have written about flawed movement pat-terns leading to cumu-lative trauma and their contributions to pain and/or an injurious Dr. Stuart McGill event. You mention that is a professor of back pain and injury sta-spine biomechanics tistics ignore cumulative at the University trauma, as do rehabilita-of Waterloo in tion strategies for pain Ontario. reduction and return to function. Can you discuss how to incorpo-rate these points into a clinical assessment in order to arrive at an optimal treatment and exercise program? Stuart McGill: In order to identify, and eliminate, the factors that are con-tributing to cumulative trauma that eventually cause pain, we assess three elements through provocative testing: these are motions, postures and loads that exacerbate pain, and those motions, postures and loads that take the pain away. If the clinician looks at the patient’s/ athlete’s daily life and movement pat-terns, “perturbing motions” can be iden-tified that are causing tissue strain and pain. From there, the doctor can proceed to perform provocative testing, replicat-ing the postures and loading that can confirm exacerbating habits. That is, you can replicate the pain by having the pa-tient play out different motions, postures and load bearing until it irritates them. This will help you identify the cause of their pain, whether they are a desk worker or a professional athlete. For in-stance, a flexion-intolerant patient who sits in spine flexion at a desk through-out the day is engaging in the activity that is causing pain. If you can identify this, through provocative testing, you can design and test a way to mitigate the www.canadianchiropractor.ca problem, for instance, by prescribing a lumbar pillow that reduces flexion. Im-mediately, their instability is buttressed and much, if not all, of their pain is re-moved. Activities such as walking, lifting, carrying and pushing can be evaluated in the same manner as the doctor deter-mines the changes needed to remove the pain. Note that these interventions fall along a continuum of stability and mo-bility. Some do better with muscle brac-ing and stiffening, and others with mo-bilization. Now, the doctor can continue with treatment strategies – therapy will have a much higher chance of succeed-ing if you can remove the patient’s pain through eliminating flawed movement or postural patterns. Similarly, with this patient in the example above, the doctor might want to avoid designing exercise routines that involve flexion. CC: You write that strength and mo-bility alone, especially in the spine, with-out control or endurance can actually increase risk. Mobility is often a prime concern, as well as a goal, for clinicians who are trying to help their patients re-turn to optimal function – for chiroprac-tors, this necessarily includes mobility in the spine. Can you discuss assessment of mobility and its role in treatment and corrective exercise design? SM: The spine can be likened to a bending beam – a beam can only be bent back and forth so many times before it starts to crack and fail with the stress/ strain reversals. The spine is like this, and even more so for some people. The spine can only tolerate so many bends before it begins to accumulate damage, eventually increasing vulnerability to in-jury and pain. Through provocative test-ing, the doctor can decide if the patient requires stabilization of the spine before trying to increase its mobility. To the chiropractor, this may mean that certain manipulations might not be the best first line of treatment, especially if specific mobility contributes to the pa-tient’s perturbed movement patterns or pain generators. For example, shear in-stability at a specific segmental level can be tested through a provocative test that also evaluates whether stiffening elimi-nates the pain. We have shown that this is the best predictor of those patients who will do well with a stabilization approach. In this case, it is more justifiable to first stabilize that patient’s spine – not mobi-lize it. Conversely, two or three initial ad-justments might change spinal dynamics enough to reduce pain and better allow for stabilization and other exercise activi-ties. In addition, mobility elsewhere may be the key in addressing some perturbed movement patterns. But only a thorough assessment of the cause of pain can eluci-date this. Mobilization through manipu-lation, and, similarly, exercise involving excessive back movements, might actually not be indicated for every patient. In addressing the strength and endur-ance issue, we have found that exercises to increase strength are not always help-ful. Giving a patient with perturbed pat-terns more strength usually results in more repeat episodes of back pain. How-ever, if they have endurance first, so that they are able to repeat tasks with per-fect form to avoid the pain mechanism, they will be able to use their newfound strength productively. So, the order of progression begins with correction of movement patterns establishing appropriate stability/mobility, developing a foundation of endurance and then, finally, strength. CC: Discuss strategies for stabilization – what does that mean in the context of the spine? SM: Research shows that, in order for the spine to be stabilized, it must be supported by an orchestra of muscles. The interplay between the spine and core muscles allows for stability in bend-ing, lifting, or whatever the individual needs to do. Research also shows that to focus on a single muscle or muscle group, through targeted exercises, will not provide overall stability. In fact, this approach will create patterns that result in decreased stability. Power is the product of force and velocity. Spine power must remain low. This is achieved by keeping one of these two variables low. If the speed is high, such as in a golf swing, then the spine muscle forces must be low. Or if the spine muscle forces are high, as in lift-ing a heavy weight, then the velocity of spine movement must be low. Here, power is developed about the ball and socket joints – the hips and shoulders. The spine transfers the power as a stiff-ened link. We have measured this pat-tern in some of the most elite athletes in the world – it is a hallmark of high per-formance and injury resilience. So, the CANADiAN CHiROPRACTOR | JUNE 2011 • 9
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