Understanding Pain
By Ned Dowling
In seeking to describe musculoskeletal pain–that is pain originating in muscles, connective tissue, bones, or joints–we have historically relied on biological models. A visit to an orthopaedic physician is very likely to include imaging and diagnostics aimed at finding an anatomical structure to blame for the pain you’re experiencing. This is not useless information. It very much serves a role in guiding medical intervention, especially when it comes to more invasive procedures like steroid injections or surgeries. It also puts a name to the pain and gives us something to blame. However, identifying the offending structure, or even qualifying it with a grade (“severe,” “Grade IV,” etc.) does not tell us exactly how to make it better, how long it will take, or a clear picture of what the individual is experiencing.
Pain is a defense mechanism to keep us from doing things that would cause harm to the body. Self-preservation is a primary part of survival, and survival is high on the list of a human’s objectives. To this end, our bodies are built with a multitude of monitoring, regulatory, and defensive systems to maintain homeostasis and survival.
The Pain Cave is a place endurance athletes frequently go (and oddly enjoy going). The body’s response to near maximum heart rate efforts is not pleasant. It’s not meant to be pleasant because there’s a point where that level of intensity is perceived as a threat. The body doesn’t like threats so the nervous system responds with unpleasantries. If we slow down enough, the unpleasantries go away and we’re pretty much back to normal.
Musculoskeletal pain is a different kind of threat and not necessarily “back to normal” as soon as we stop. But it is still a nervous system response to a perceived threat. The origin of all musculoskeletal pain is an imbalance between loads being placed on the body and the body’s ability to tolerate those loads. Sometimes that load happens in large quantities very quickly like an ACL tear, a fracture, or a sprained ankle. With endurance athletes, the imbalance tends to arise more slowly with small amounts of overloading accumulating over time. Eventually, it becomes more than the body can handle, or thinks it can handle, and the nervous system triggers a pain response.
The magnitude of pain is not always consistent with the degree of injury. A papercut hurts like hell, but it’s not going to kill you. Interestingly, the pain also tends to go away before the skin is fully healed. In this case, the nervous system is still sending the “danger” signal to the brain, but the brain no longer perceives the papercut as a threat (“oh it’s just a stupid papercut, we’ve had those before and it’ll be fine–nothing to worry about”) so the pain goes away. Until we squirt some lemon juice in there and the threat level escalates, then the pain returns.
Imaging is not always accurate. It is very precise–MRIs are incredibly good at finding things. So good, in fact, that they will often find things that don’t matter. There have been numerous research studies that collected asymptomatic people and performed MRIs only to find that a large percent of those people with no musculoskeletal pain had adverse findings (the likelihood of a positive finding is roughly the same as your decade of life–50% of 50-somethings will have an adverse finding even when they don’t have any pain). Again, the imaging isn’t useless; it just doesn't tell the whole story. It needs to be taken in the context of the symptoms and clinical presentation.
Because of the way that we experience pain, because it is a product of our brain’s interpretation of a nerve signal, we can have minor injuries that are quite painful, we can have pain that doesn’t appear to have a clear anatomical culprit, and we can have pain that lingers long after the injury has healed. Researchers and clinicians are discovering that the individual’s perception of pain may have as much influence on their symptoms as the injury itself. This is especially true in athletes whose identity, self-efficacy, social network, and potentially livelihood depends on their ability to train and compete. When pain is the prohibitive factor and influences so many aspects of mental health, it tends to gain a greater piece of headspace than it deserves.
Ultimately, we need to balance the relationship between load and tolerance. On the load side, this means modifying the training plan (at least in the short term) and potentially addressing inefficiencies for the long term (decreased efficiency = increased load). On the tolerance side, this means calming it down and then building it up. This applies to both the physical aspects and the mental/psycho/emotional aspects of the symptoms. Sometimes this process is relatively quick and easy, but sometimes it is long, drawn-out, and frustrating. But our bodies really are quite good at healing and adapting as long as they are given the right conditions, time, and opportunity. Surround yourself with a good team of both medical providers and emotional/social support providers. Trust the process and trust your body.