If you have ever been to a physiotherapy consultation, you would likely have left with a little bit of ‘homework’ in the form of strength or mobility exercises. Now as a physio myself, I am fully aware that people complete their ‘homework’ to varying degrees. Some are incredibly diligent, some will do it once or twice, and some immediately leave the clinic and forget the exercises in the hope the physio does not ask about them next time. Exercise prescription may seem like an annoying part of the treatment process, but it is often the most important factor in your rehab, addressing problems found within the assessment to help you return to a pain-free level quicker and for longer1. The exercises physios give are planned, specific and structured, with a purposeful reason behind the delivery and application in the hope of achieving a desired result.
Exercise can work through multiple methods, but the two reasons I most commonly prescribe exercises for are, firstly, to improve the capacity of the injured tissue to tolerate load, and secondly, to change the way the brain is interpreting painful movement1,2,3. Each factor is important in its own right, and they are uniquely intertwined throughout the rehab process. Figure 1. demonstrates the unique load management interaction between injured and uninjured states, highlighting how improving tissue capacity is a process of progressively increasing the load/stress placed on the area.
Figure 1. Rehab training and loading principles
Through prescribing specific and progressive strengthening exercises, physiotherapists aim to improve the strength of the injured and surrounding areas by improving the tolerance and capacity to take load and control movement. Tissue capacity improves through a process called ‘mechanotransduction’, which is essentially the body converting a stimulus (action on the body) into an internal response2. For example – a force is applied to the body (strength exercise), in response, cells communicate with each other to increase production of that tissue/muscle = improved strength (capacity)2. In order for this process of mechanotransduction to occur, the load applied to the tissue has to be higher than normal (but not too high that the area is overloaded), which is an important factor in the rehabilitation process2.
Another factor rarely considered is that of exercise induced pain relief, which can have positive effects on both acute and chronic injuries. One of the primary theories of this pain relief is the mechanism of enzyme release from the body which acts at the painful area to decrease pain and improve function following exercise3. Consistent and increasing exercise over a period of time can cause an increase in both enzyme AND receptor production, which can cause a sustained increased in this pain relief (long term improvement in pain)3. An equally important aspect of pain relief following exercise is the change in brains perception of pain. Pain is a complex process that is not just related to damage to a particular area, rather it is a multifaceted process which includes both tissue injury and the brains perception of noxious/pathological stimuli4. Through progressive movement/exercise (specific and guided) involving the injured area, the brain begins to change its processing of movement from being noxious/negative to normal and we improve both our strength and control4. As movement is now seen as ‘normal’ by the brain/body, we can overcome this process of fear of movement, which is incredibly important, particularly in longer term rehabilitation.
Now, you do not have to think of this the next time you see a physio and they send you away with a few strength exercises, however, just appreciate that your body is strong and adaptable, and movement is key to keeping it that way. Here at Bayside Sports Medicine, we use a program/app called Physitrack to help with your exercise prescription, making it easily accessible on your phone/tablet and allowing effective communication with your physio between consults. If you have a nagging injury you think needs to be strengthened, come see one of our experienced clinicians to help you get back to full strength!
References
1. Elizabeth Anderson, & J. Larry Durstine. (2019). Physical activity, exercise, and chronic diseases: A brief review. Sports Medicine and Health Science, 1(1), 3–10. https://doi.org/10.1016/j.smhs.2019.08.006
2. K M, K., & A, S. (2009). Mechanotherapy: how physical therapists’ prescription of exercise promotes tissue repair. British Journal of Sports Medicine, 43(4), 247–252. https://doi.org/10.1136/bjsm.2008.054239
3. Joseph B., L., & Kathleen A., S. (2020). Mechanism of exercise-induced analgesia: what we can learn from physically active animals. PAIN Reports, 5(5), e850. https://doi.org/10.1097/PR9.0000000000000850
4. Ongaro, G., & Kaptchuk, T. J. (n.d.). Symptom perception, placebo effects, and the Bayesian brain. PAIN, 160(1), 1–4. https://doi.org/10.1097/j.pain.0000000000001367