Anatomy of a Running Injury – Part 1

A look at how training forces and tissues interact to cause running injuries.

By on March 14, 2012 | Comments

Stay the CourseOne of the best running gifts I’ve ever received was a copy of Dr. Tim Noakes’ formative work, The Lore of Running. In this exhaustive resource on all topics running, Dr. Noakes outlines his “Rules of Running Injuries.” Front and center at number one:

Running injuries are not an act of God.

In the ultra world, there may be a few God-inspired injuries – that root the reaches up and grabs your toe or the rocky formation that gives way beneath you – but that’s a topic for another time.

So if not God, luck, or superstition, then what?

An injury is the result of an abnormality in the interplay between forces – training load, surface, and gait mechanics – and tissues – muscle, tendon, bone, joint, nerve, or anything that’s you! Let’s take a closer look at that interplay:

Normal Forces on Normal Tissue
Normal forces – namely training load and running techniques – are those deemed reasonable and tolerable to the human body. Normal tissues are those deemed to have healthy degrees of strength, flexibility, nutrition (blood flow), and power supply (nerve connection).

Normal is seldom equated to ultrarunning. But via tissue adaptation, we advance our fitness – and ability to survive ultra training and racing – by increasing force loads gradually. This gives our tissues enough time to adapt, creating new normals of both forces and tissues. Simply put, we load the tissue with our easy runs, interspersed with harder, longer runs that over time push the envelope of normalcy to a new level. This is the scenario of the healthy, and often successful, athlete.

Abnormal Forces on Normal Tissue
Problems arise when the forces become abnormal. Any force that the body’s tissue cannot absorb in a finite time – be it a hundred-mile week or a single leap off a high rock – is deemed abnormal. This results in an adverse tissue response: pain, inflammation, and/or mechanical compromise such as a strained calf or tweaked Achilles. These are straightforward examples that everyone has experienced, and they’re typically deemed “training errors.”

Normal Forces on Abnormal Tissue
Abnormal tissues are those that no longer have requisite strength, range of motion, nutrition, or power. This can occur for a variety of reasons: being overloaded by abnormal forces in running or losing flexibility and strength after a long lay-off. Non-running stressors, such as work or home tasks, can also change the nature of your tissues. A common example is traveling: sitting on a plane or car stiffens the spine, resulting in a back strain during an easy run or race.

Abnormal Forces on Abnormal Tissue
This is the area where chronic injury is born and raised. Tissues are made abnormal by the injury process. Inflammation results in tissue shortening: muscles tighten, tendons scar, joints stiffen. But just as likely, the resting process can make tissue abnormal, by taking tissues that were kept fed and flexible by exercise are now lying dormant.

But what about forces? Shouldn’t they be normal, or “better than normal,” due to lower training loads when we come back from injury or a lay-off? Perhaps, but what if running mechanics become abnormal?

A less-recognized – but arguably more threatening – example is when the abnormal force becomes one’s own running mechanics. Abnormal or inefficient running mechanics – occurring either suddenly or gradually – put abnormal forces on tissues that, under previously normal volumes, were well-tolerated. But now, they create injury.

Pain As Your Teacher
Pain is the world’s greatest teacher: it is the feedback system that protects us from danger. Without it, we’d all be dead. As such, it has tremendous ability to change the way we function, without any knowledge or conscious control. Consider if we had to think about whether or not to remove our hand from a red-hot stove burner.

Pain changes how we run. It changes how powerfully we use a muscle, or how much weight we put through a joint or limb. It changes how much we move a limb through space or how quickly. So when we experience the pain of an injury, the potential for changes in our running mechanics – however minor or seemingly insignificant – is substantial and altogether shocking.

Previously normal running mechanics have now become abnormal. Coupled with abnormal tissues equates to poor tolerance to even miniscule loading forces, resulting in chronic injury.

This is why Dr Noakes’ 7th rule rings true: “Complete rest is seldom the most appropriate treatment.” Unless you change the abnormal tissues or abnormal mechanics, the symptoms will invariably return with resumption of running.

A good case study was a friend of mine with left knee pain. She’s had pain for three months since running a 50k race. Prior to the race, she had no knee pain, so we can assume pre-race forces and tissues to be normal. She successfully finished the 50k, but experienced minor knee soreness in the week afterward (assumption: the race was an abnormal force). Following a three or four day rest, she completed a short run without pain (normal force). But upon her next run, she experienced knee pain.

Since that time, every subsequent run, despite taking days to weeks off running, and returning with very light trial runs, resulted in pain.

Why would this scenario – tons of time to rest, then significantly shorter and easier runs – result in the same pain?

Upon examination, I found the following issues:

  • Range of motion losses in the ankles and knees, namely the quadricep and patellar tendon on the left side. These represent abnormal tissues.
  • During run gait, she was pushing off less powerfully, resulting in a valgus (sidebending) force during landing. Also, she bent her left knee less during the swing phase. These represent abnormal forces.

Without addressing the abnormal tissues and forces, my friend would continue to have pain. Therefore, to successfully treat this injury, we addressed the tissue mobility and the gait mechanics. Once those two issues are ameliorated, there is no reason why she cannot return to running soon, and eventually run another 50k.

* * * * *

Given that, the most effective way to both treat injury – and remain injury-free – is, quite simply, to keep both forces and tissues normal. This is easier said, than done. But here are some brief things to focus on:

  • Be Consistent. Consistency in training and life keeps both forces and tissues near-normal. Abrupt changes can result in overload and changes to both tissues and gait mechanics.
  • Know “Your Normal” and Keep It That Way. I am frequently asked, “What do I need to stretch as a runner?” My answer is, “Whatever needs stretching.” Know your norms: can you normally touch your toes or your heel-to-your-butt? Can you squat down and keep your heels down (e.g., ankle flexibility)? If so, keep it that way.
  • Know How You Run. This is a tough one (and fodder for more than one subsequent post, for sure). Do you know how you run, or how to sustain your stride when fatigued, or sore? Keep your mechanics consistent at all costs: consider working with a coach or knowledgeable runner to provide feedback or develop drills that help maintain a consistent stride. Even in an absence of pain, the natural aging process can – and does – change our stride by slowly making our tissues stiffer. Stay flexible and stay consistent. Don’t go down without a fight!
  • Never, Ever, EVER Limp.* We have but one rule at our clinic, “No Limping Allowed.” Limping, or compensatory gait, changes both tissues and forces: over- (or under-) loading tissues, and changing our mechanics. Most people suffer a slight injury, compensate, then suffer greatly from the compensatory changes in tissues and mechanics. Don’t do it!

(*unless you’re on the Placer High School track at Western States)

In our next article, we will delve into Part II and talk about how to make Abnormal become Normal again, and how subtle changes to mechanics in response to pain can create chronic injury.

Call for Comments

  • Do you have any examples of abnormal forces and abnormal tissues resulting in injury?
  • What do you do to maintain “normal tissue” (e.g. strength, flexibility)?
  • How mindful are you about your own running mechanics? Have you ever sought out assistance from a coach or health care provider to improve your form?

[The contents of this column as well as the author’s comments are provided for general informational purposes only and are not intended as a substitute for professional medical advice. Do not use the information on this website for diagnosing or treating any medical or health condition.]

Joe Uhan

Joe Uhan is a physical therapist, coach, and ultrarunner in Auburn, California. He is a Minnesota native and has been a competitive runner for over 20 years. He has a Master’s Degree in Kinesiology, a Doctorate in Physical Therapy, and is a USATF Level II Certified Coach. Joe ran his first ultra at Autumn Leaves 50 Mile in October 2010, was 4th place at the 2015 USATF 100k Trail Championships (and 3rd in 2012), second at the 2014 Waldo 100k, and finished M9 at the 2012 Western States 100. Joe owns and operates Uhan Performance Physiotherapy in Eugene, Oregon, and offers online coaching and running analysis at