Inadequacies in current care and prevention
Many back patients can testify that the care they have received for their troubles is not satisfactory. Conversations with family doctors give the general impression that they do not know what to do with cases of back pain except to provide analgesics and perhaps a referral to a surgeon or therapist. They have neither the time nor the expertise to provide specific help matched to the patient, and suggesting that they engage in a non-specific activity such as yoga may be equally helpful as harmful – the net gain is zero, begins Stuart McGill.
Carey and colleagues (2009) documented practice patterns in 5,357 households in North Carolina, USA. Of the 732 adults with chronic lower back pain, 60% had used narcotics in the previous month, and more than one-third had advanced imaging in the previous year, yet only 3% had engaged in formal spine rehabilitation. The discrepancy between the over-emphasis on expensive treatments and the under-utilization of pain-reducing movement and exercise is clear.
What are some of the factors that contribute to the inadequacy of patient experience? One factor is certainly that the epidemiological evidence on which many professionals base their treatment recommendations can be quite confusing. The following are some examples of the issues that can cause such confusion.
Plethora of studies on ‘backache’
Non-specific backache is nearly impossible to quantify, and even if it could be quantified, offers no guidance for intervention. As such, any study of treatment interventions on non-specific backache is of little use. Some people suffer from discogenic problems, for example, and will respond quite differently to those with ligamentous damage or facet-based problems. Efficacy studies that do not sub-classify bad backs end up with non-specific average responses. This has led to the belief that nothing works – or that everything does, but to a limited degree. More studies on non-specific backache treatment will not be helpful, nor will the large epidemiological reviews of these studies offer real insight. In contrast, patients with treatments matched to their conditions experience greater short- and long-term reductions in disability than those receiving unmatched treatments (Brennan et al., 2006; Fritz, Cleland and Childs, 2007).
U-shaped function of loading and resulting injury risk
Like many health-related phenomena, the relationship of low back tissue loading to injury risk appears to form a U-shaped function – not a monotonically rising line. For example, virtually every nutrient will cause poisoning with excessive dosage levels, but health suffers in their absence; thus, there is a moderate optimum. In the case of low back loading, evidence suggests that two regions in the U-shaped relationship are problematic – too much and too little. Porter (1987) suggested that heavy work is good for the back, but how does one define heavy? Porter was probably referring to work of sufficient challenge and variability to reach the bottom of the U and hence lower symptoms. From a biological perspective, sufficient loading is necessary to cause strengthening and toughening of tissues, but excessive levels will result in weakening. In other words, it is not a matter of doing exercise or not, or engaging in activity or not. Heneweer, Vanhees and Picavet (2009) expressed the need to match the appropriate activity and its level for seeking the optimal point on the U-shaped relation for back pain.
Relationship of intensity, duration of loading, and rest periods
As Ferguson and Marras (1997) pointed out, some studies suggest that a certain type of loading is not related to pain, injury or disability, whereas others suggest it is, depending on how the exposure was measured and where the moderate optimum for tissue health resides for the experimental population. The subjectivity of such studies is further underscored when we consider the question of whether there is a clinical difference between tissue irritation and tissue damage. Loading experiments on human and animal tissues to produce damage reveal the ultimate tolerable load beyond which injuries cause biomechanical changes, pain, and gross failure to structures. In real life, any of us could irritate tissues to produce tremendous pain at loading levels well below the cadaver-determined tolerance by repeated and prolonged loading. In fact, evidence presented by Videman and colleagues (1995) and Niemelainen and colleagues (2008) suggests that the progressive development of conditions such as spinal stenosis results from years of specific sub-failure activity. The fundamental question is, could such conditions be avoided by evidence-based prevention strategies that include optimal loading, rest periods, and controlling the duration of exposure?
About the author
Dr. Stuart M. McGill is a professor emeritus, University of Waterloo, where he was a professor for 32 years. His laboratory and experimental research clinic investigated issues related to the causal mechanisms of back pain, how to rehabilitate back-pained people and enhance both injury resilience and performance. This produced over 240 peer-reviewed scientific journal papers, several textbooks, and many international awards. He mentored over 40 graduate students during this scientific journey. For more information, visit: http://www.backfitpro.com/about-us/
This extract is from ‘Low back disorders’ – evidence based prevention and rehabilitation by Stuart McGill. Visit Human Kinetics to find out more about the chapters and to purchase the book: http://www.humankinetics.com/products/all-products/Low-Back-Disorders-3rd-Edition-With-Web-Resource
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