I get many of my blog ideas while running. You may be surprised to know how much random thought a cortex can generate with blood pumping through it at 150 beats per minute. I began thinking about how lucky I am to be training as much as I do, but have yet to encounter an overuse injury. Overuse injuries sidelined my first attempt at training for a marathon back in 2000 in the form of heel and medial knee pain. I have been eager not to repeat my mistakes of the early millennium, and fortunately (currently knocking on wood) have avoided any roadblocks.
Many of our patients in an outpatient orthopedic setting haven't been so fortunate. Activities such as running, bicycling, and swimming can be physically demanding enough to overwhelm a vulnerable weak link within the patient. It is very likely that the body does its best to compensate for this vulnerability. However, just as in life, in the absence of a fundamental change in training load, a weak link is nearly always exposed. In the case of physical activity, the stereotypical "overuse" injury results.
Mechanisms of Overuse
Overuse injuries can occur for a variety of reasons including a premature increase in training load (distance, speed, intensity) or inadequate recovery between bouts of activity. Most injuries are capable of healing in the standard inflammatory-nociceptive pattern if afforded the right environment.
However if you've treated what some refer to as obligatory exercisers, you'll realize that some folks have a tough time giving themselves the best opportunity to heal. The condition transitions from medial knee pain to chronic medial knee pain. Even more frustrating for the patient is that the medial knee pain will persist despite reductions in training load and attempts at standard and even non-standard rehabilitative care. Pain may begin occurring at lower training thresholds or even at rest, leaving the patient feeling painted into a corner of inactivity. It doesn't take long for frustration to deteriorate into depression and eventually dropout.
It's important to note that even the best training programs and access to care will not prevent some injuries. If that were the case, professional athletes would never develop an overuse injury. The ones that do would be rapidly rehabilitated and miss very little playing time. Obviously even professional athletes encounter these kinds of issues, and suffer greatly for them. This despite well planned primary preventive and treatment programs.
Let's face it, we all understand the inflammatory process and concepts related to overuse. We are capable of explaining these concepts to our patients and assuring that they understand the means to avoid overuse injuries. Yet these problems continue and occasionally flourish! I propose taking a hard look at how we manage these injuries with the following observations in mind:
- Chronic overuse injuries often persist well beyond cessation of the precipitating activity such as running or throwing.
- Overuse injuries often persist in the presence of normal strength, flexibility, and normal variations of posture and biomechanics.
- Overuse injuries such as lateral epicondylalgia and anterior knee pain often show no clinical or histological signs of a local inflammatory process.
- The pain associated with overuse may persist following a well-planned rehabilitation program consistent with our current standards of care.
Recent evidence suggests that the longer a painful condition exists, the less likely it will behave as a traditional inflammatory/nociceptive condition. It has been fairly well-established that peripheral and central neurophysiologic mechanisms can maintain a condition long after the tissue has healed. Factors such as up regulation of receptor volume at the site of injury, dorsal column, and even supraspinal regions make central sensitization a likelihood for chronic overuse injuries. The trouble is how to incorporate an understanding of these events into our treatment plans?
Unfortunately, this isn't a simple matter. We are just now (over the last 10-15 years) years) becoming aware that central mechanisms play a role in the maintenance of these conditions. As a result there are scant outcome studies and no CPRs. All we can rely upon right now is the best available evidence, our clinical judgement, and the interests of the patient to guide our interventions. My own approach is to educate the patient about the local and central physiology of their chronic condition. Education has been a fairly well established way to manage disability in patients with persistent low back pain, and I believe their is some carryover in the "overuse" population.
The focus of my education is along the same line as David Butler's user-friendly educational book Explain Pain. It starts with a very simple explanation of what causes the initial onset of pain and the mechanisms of how it can become chronic. Having a clear understanding of the physiology of pain is helpful here because the patient will often ask many very good questions.
There are two very powerful benefits to this approach. Firstly, the patient loses the notion that "something MUST be wrong". Often these folks have been told that there are minimal radiographic or clinical findings to correlate with their symptoms. This often leaves the patient with a sense of dread regarding their condition's prognosis. You can relieve this stress through a fairly straightforward educational session about the mechanisms of their pain. The patient leaves the session with a sense of understanding and confidence about their potential to recover from their condition. The physiologic mechanism behind this process includes supraspinal descending inhibition through structures such as the periaquiductal grey, anterior cingular cortex, and amygdala of the brain. These structures are felt to be responsible for the analgesia produces by events such as positive expectation, placebo, and other psychosocial factors.
Secondly, the patient now has a well-informed basis for action. This has tremendous advantages in that the patient will be less likely to undermine your care plan when they aren't in the clinic. There is strong evidence to suggest an informed individual will engage in conscious and subconscious movement patterns that foster a good healing environment. This will allow for a more complete resolution of damaged tissue and reduce the likelihood that pain will persist. The patient will eventually take a more logical approach to their activity progression and maintenance. The end-result is an informed patient who has all the skills they need to get out of their current condition and reduce the likelihood for a relapse.
This educational probably isn't entirely different from what many other therapists are doing in their clinics, but I believe it does require some effort. Not every patient has the same educational background and learning style. As a result, your teaching methods will need to vary considerably between patients. Secondly, it requires the therapist to have a well-developed understanding and integration of the inflammatory process, pain science, and principles of training and conditioning. A more complete understanding of these fields can be very beneficial for patients suffering from chronic overuse injuries.
I hope this glimpse into my approach to this troublesome condition is useful for you mainly as a primer for further study into these disciplines. It has definitely helped my practice over the last year. After submitting this entry, I'm going to walk outside and try to set a personal record in my 10K. Wish me luck and an injury-free morning!
Take care and feel free to comment on this or any other blog. I always welcome the discussions.