In musculoskeletal medicine, healthcare professionals do a reasonably good job of treating the tissue injury. Treating the person is a tad more challenging. Just take back pain for example. It’s the leading cause of years lived with disability (Vos et al., 2012) in the western world, so collectively as health advisors, we could be doing a whole lot better in that department and humanity needs to consider appropriate lifestyle choices. I will only speak from the clinical viewpoint and highlight that the problem is some allied health professionals are still treating the tissue or body part, viewing the body as machine and not helping or supporting the person. Physios, osteopaths, chiropractors, massage therapists, there are many of us that are still encouraging a passive dependency and cautious approach to treating injury and pain, when we should be advocating more of an active approach for the person to be engaged in their rehab.
‘I would venture to suggest that you cannot become an expert practitioner unless you quickly realise that a patient’s body as a machine is largely inadequate for the real world of practice.’ (Nicholls, 2017)
I am frequently told by patient’s messages they have received from other health professionals about what they should and shouldn’t be doing. Honestly, the mind boggles sometimes! What really irritates me is when people are told they shouldn’t be doing any physiotherapy or more specifically any rehab for the injured area, or they’ve been told not to do an activity but have not been told for how long or if they should ever do the activity again. This is usually something stupid like bending and last time I checked it is nigh on impossible not to bend in most activities of daily living.
Now it’s fair to say that most health professionals are aware of the poor relationship between pain and tissue damage and hopefully they are also aware of the potential behaviours and beliefs that can coincide with pain, particularly fear avoidance and catastrophizing and these contribute to the biological construct of persistent pain (B. Smith et al., 2017). Something that tends to occur more regularly than not is people experiencing pain when they exercise. Anybody with persistent pain is highly likely to be aversive to the idea of exercising for fear of increasing their pain levels. Furthermore, the evidence also points to clinicians fear being a large deterrent to people exercising with pain (Littlewood, Mawson, May, & Walters, 2015).
In the same token, clinicians are also aware of the benefits of exercise or activity in reducing chronic disease and improving tissue resilience. So, let’s look at few effects of exercise that will benefit the injured body part and the pain but doesn’t specifically involve movement of the affected body part.
At this point I should highlight that we certainly don’t want to add to a person’s avoidance behavior, by not getting them to move the injured body part. In fact, when it comes to persistent pain that’s exactly what I want to do. However, I have found these approaches have helped people to understand the variety of benefits exercise or activity can have on their road to recovery and can use it as a means to increase someone’s confidence to move and be less aversive to pain.
Metabolism and dosage
We have all known for a long period of time about the effects of anabolic and catabolic metabolism on tissue health and regeneration and even on your mental well-being.
Simply, anabolic is ‘to build up’ and catabolic is ‘to break down.’ What happens when we exercise? Well, you begin to stress your tissues and you utilize energy stores (catabolic process). As a result, your tissues start to adapt (anabolic process) and become more resilient. So, when you exercise you actually make your tissue more resilient, and it’s not just the injured tissue, it’s a whole-body effect.
So, stress is good for us but there’s always a but.
The stress you place upon your body must not exceed its capacity to adapt.
Prolonged periods of stress including exercise can have a negative impact upon our body and mental health. Periods of recovery are hugely important as it help to replenish energy stores and regenerate tissue. Yet too much rest can also have a negative effect. So, it’s all about balance and dosage of your rehabilitation. It’s important to find a dosage that works for the person and finding one that is minimally effective (encourages an anabolic / catabolic process) is usually a good start as you can always progress their program.
A take home message, if you push too much too soon you’re likely gonna end up sore or if you are not used to doing an activity and you push through, yup, you’re likely gonna end up sore. So, thinking about how much you do (volume) how hard you do it (intensity) the number of times you do it (frequency) and how long you do it for (duration) is all part of what makes up the dosage of the activity. If you go beyond all that you have capacity for then you’ll likely end up sore. It’s also important to monitor what happens to your pain following activity. Does your pain ease down to base line within a couple of minutes or does it have a latent period of being grumbly? If this is the case, physiologically you are likely sensitized and you want to respect pain and not push through it.
In summary, when a medical professional says not to continue with exercise for the injured body part, general exercise has it benefits for the whole body and it’s worth identifying what the appropriate dosage might be for the injured body part.
The cross-over phenomenon
This is a weird and groovy phenomenon whereby if you exercise the non-injured body part the injured body part also becomes stronger. This likely due to neural adaptation (Hendy, Spittle, & Kidgell, 2012)although the research in this area is still limited. Studies have failed to identify if the reason for strength gains in the untrained limb is due to muscle adaptation and so it is likely due to neural mechanisms, it appears, primarily in the cortex of the brain. The reason why this happens is understood to be due to the corpus callosum which connects the left and right hemispheres of the brain. So, any training you do on the uninjured side will stimulate the corresponding sensory motor cortex and also the opposite sensory motor cortex. I also suspect that there’s likely a contextual factor in this as we tend to do use both hands for a lot of tasks we do throughout the day such as typing, lifting, driving, eating, communication. Therefore, injured or not there will always be activity in the brain working reciprocally between left and right hemispheres. What makes this even more interesting is when pain starts to develop in the non-injured side when using the injured side. This is something I have experienced in a lot of the people I see.
The final effect in our exercise arsenal is exercise-induced hypoalgesia (EIH). Exercise has been shown to have a pain suppressing effect. Many studies have shown in a few different ways how we can induce the pain suppressing effect. Aerobic exercise and isometric exercise has been shown to provide pain suppressing effects in healthy individuals and people with various persistent pain problems including Low Back Pain, Knee Osteoarthritis, Chronic whiplash and even fibromyalgia. In terms of aerobic exercise to induce EIH evidence points to high-intensity exercise for a duration of up to 30 minutes or as little as 10 minutes (Vaegter, Handberg, & Graven-Nielsen, 2014). Other studies have found that aerobic exercise at 70% – 75% of VO2 max is enough to promote EIH (Jones, Booth, Taylor, & Barry, 2014; Nijs, Kosek, Van Oosterwijck, & Meeus, 2012).
Isometrics have also been shown to promote EIH either after direct contraction of the affected limb or contraction of muscles distant from the injured body part (Rio et al., 2015; Vaegter, 2017). Examples include a clever study identifying that an isometric wall sit for 3 minutes produced widespread EIH in people with chronic whiplash. Interestingly in the same study researchers found that 30 minutes of aerobic exercise had no effect at all on people with chronic whiplash (A. Smith et al., 2017).
Weight lifting of low or high loads over a 6 week period found an improvement in pain intensity and disability in people with low back pain in the short-term and long-term follow up (Michaelson, Holmberg, Aasa, & Aasa, 2016).
So generally, exercise is good for a number of conditions however there does appear to be a relationship between something called conditioned pain modulation (CPM) and EIH. That CPM predicts EIH (Lemley, Hunter, & Bement, 2015). What is CPM? It is a central or supraspinal inhibitory mechanism or more simply pain inhibits pain (Lewis, Rice, & McNair, 2012). Now because exercise in some cases is perceived to be painful (think about pushing yourself on a spine bike for 30 minutes at full intensity and tell me that’s not painful!) it has been suggested that individuals with persistent pain have a inhibited CPM mechanism and therefore the effects of EIH may be suppressed in these individuals (Lewis, Rice, & McNair, 2012). So how do we assess CPM clinically? Well that’s for another blog.
So, next time your patient is told not to exercise by another health professional or you as the patient is told that you should stop exercising the body part, maybe consider chatting to your health professional first about how exercise can work for you rather than against you. Remember this message:
Thanks for reading.
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Jones, M. D., Booth, J., Taylor, J. L., & Barry, B. K. (2014). Aerobic training increases pain tolerance in healthy individuals. Medicine and Science in Sports and Exercise, 46(8), 1640–1647. https://doi.org/10.1249/MSS.0000000000000273
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Rio, E., Kidgell, D., Purdam, C., Gaida, J., Moseley, G. L., Pearce, A. J., & Cook, J. (2015). Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy. British Journal of Sports Medicine, 49(19), 1277–1283. https://doi.org/10.1136/bjsports-2014-094386
Smith, A., Ritchie, C., Pedler, A., McCamley, K., Roberts, K., & Sterling, M. (2017). Exercise induced hypoalgesia is elicited by isometric, but not aerobic exercise in individuals with chronic whiplash associated disorders. Scandinavian Journal of Pain, 15(November 2016), 14–21. https://doi.org/10.1016/j.sjpain.2016.11.007
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