“Anatomy for Runners”: Excerpt on Why Runners Get Injured by Jay Dicharry

by Jay Dicharry.

Running is pure. You may run for yourself, seeking to improve your time on your local neighborhood loop, or maybe simply to knock out the stresses of daily life. There are few other sports in the world in which you can compare yourself purely against the clock. It’s just you covering distance against time.

And herein lies the catch.  Information for runners has been tailored to the advancement of training the heart and lungs— the body’s engine. You could fill an abyss in the ocean’s floor with all the information available to help runners and coaches understand the physiology of running. No matter your personal bias or interpretation of this knowledge base, it plays a significant role in your training your engine. However, engines—even big ones—don’t move on their own.

Like most kids from the Nintendo generation, I grew up playing my share of games. I liked racing games when I was a kid and a lot of them followed a similar format. They start you off with a simple car for your first race. As you improve your skill on the racetrack, you win races and get “money” that you can use to upgrade your car. It’s pretty simple really. Spending your prize money on a bigger engine means you can hit very high speeds. Hey, it’s fun to go fast, right? However, you soon realize that all that horsepower leads to a crazy bucking bull in the corners. You just can’t keep it stable in the turns unless you spend some dollars on suspension and tires. The video game almost “forces” you to follow a well-rounded progression of your car because sinking all of your dollars into one category doesn’t give you what you need to win the race.

It’s not just virtual reality—talk to any rally or auto racer and they’ll tell you firsthand that they spend more time tun- ing their suspension and tires than they do on their engine. All of that horse- power needs to be transferred through a stable chassis if you want to see the fruits of your labor.

Apparently, most runners didn’t play video games back then because running has turned into some crazy type of badge-of-courage sport in which you have to pound yourself into shape day in and day out until you emerge on top. Most runners don’t spend time working on their chassis because Coach simply expects more and more miles. There is one incredibly big problem with this idea that more is always better. It’s not true. That’s right. How can anyone make this statement?


Eighty-two percent of runners get injured. That’s an astounding statistic, isn’t it? If eighty-two percent of drivers were getting in wrecks each year, we’d see some pretty major things happen to prevent all these folks from getting hurt, right? So you go see a clinician to get help, and what do you hear? Unless your clinician is a runner himself, like other clinicians, he thinks all runners are nuts. You are told that “running is bad for you” and you should stop. Since this has never been proven true, maybe we should reexamine our approach towards running injuries. Maybe it’s time to educate ourselves a bit more on what running really does to the body so you can better prepare—and stay healthy

Engines develop horsepower. More horsepower is better, but it’s useless unless it sent to the wheels through a stable chassis. The analogy holds true for runners and their bodies.

Recently, headlines have focused on evolving trends in barefoot running, footwear, and “proprietary” one–for–everyone running form. Thankfully, these headlines have given runners reason to think about running technique. However, somewhere along the line, someone forgot about the individual runner. While moving the runner forward against the clock is what counts, it’s how the body uses its chassis to stabilize in the lateral and rotational planes to move forward that affects our injury and performance potential.


What causes injuries? Most runners don’t sustain major traumatic events like falling off of a cliff. The thing that gets runners is compounding microtraumatic loads applied to the body mile after mile. Sometimes we ramp up volume too quickly, add too much high intensity work without enough rest, and then we keep pushing through the soreness, aches, and pains, and end up limping. Does this sound familiar? Likely all of you have been guilty! Well, guess what. Your body keeps putting up with your stupidity until it can’t anymore.

The F.I.T. (Frequency, Intensity, and Time) are just too high to allow proper adaptation of the body’s musculoskeletal structure. What does this mean? If we respect the properties of tissue mechanics, we’ll better cope with keeping things intact. A training plan that is not set up for individual progression, or one that ignores the mechanical nature of the body’s tissues, results in overuse injury.

Sometimes it’s not what we do to the body that causes injury (like following a bad training plan), but rather a breakdown within the runner. Perhaps they don’t have enough mobility at a specific joint, which forces excessive motion at another joint. Maybe a muscle imbalance prevents them from stabilizing the body. Or it may be a limp that has crept its way into their stride over the years of which they are unaware. Any one of these can act independently or in combination to load the body excessively. It’s time to shift our focus to a concept called causative biomechanics, and it’s the aim of the rest of this book.

Injured runners typically are told to “rest” or follow the typical advice of RICE (Rest, Ice, Compression, and Elevation). While resting/RICE are great strategies for acute injuries or some injuries like fractures, they rarely serve a purpose in long-term management, correcting the reason for the specific injury, or prevention. So many runners “wait around for things to get better and go away.”

Why not take the bull by the horns? Find out why you got hurt and fix that problem while waiting for the symptoms to subside. We are not talking about cross-training. We are talking about correcting the biomechanical factors that caused you to develop your injury in the first place. Even having an injury that requires complete rest is not an excuse.
I often have runners working on corrective exercises well before they are back on their feet. If you understand the specific factors causing your injury, you can often speed the healing rate and often emerge a better athlete than you were prior to the injury. If this sounds like a good idea to you, let’s dive in together.

It’s understood that a specific F.I.T. of training is required to improve
 the cardiovascular system—the engine. Athletes tailor their training to im-prove specific outcomes, or limiters. If you want to improve your endurance, the priority shifts to longer distance training at lower intensities so that the body can improve its ability to transport oxygen and utilize fat as an energy substrate. Likewise, if top-end speed is the goal, the emphasis shifts towards higher intensity work with long rest between repetitions so that intensity can be maintained for the duration of the workout. Training is targeted towards specific central and peripheral adaptations. Central adaptations refer to the ability to carry more oxygen and nutrients to working tissue. Peripheral adaptations occur inside the local muscles to improve the extraction and utilization of the oxygen and energy substrates delivered. Just as there is a science that governs the principles that we use to develop the engine, there is a science that governs the development of the chassis.

To optimize the training adaptations of the chassis, the stresses on the tissues need to be kept within their optimal window. Training loads create a stimulus for the body to help you heal and emerge a stronger you. Wolf ’s Law states that tissues in the body adapt to the loads placed upon them. Training breaks the body down. If the rate of recovery matches the rate of breakdown, the body will maintain its current state. To improve the connective tissues that make up the chassis, the load needs to be increased to some point. When the training load falls on either side of the optimal, the repair process is compromised. If the load is too high, such that the body cannot fully recover prior to the next workout, breakdown can occur. Likewise, too little activity results in the body’s tissues becoming weaker. This is why simply resting doesn’t yield stronger tissues. Further, not every tissue in the body adapts at the same rate. Sometimes the body needs to be assisted to help it repair correctly. Specific loading of tissues helps the body repair.

An all-too-common scenario: Paul is a high school runner living in the city who has been carefully ramping up his training volume over the summer to develop a solid base for the fall cross-country season. His workouts have stressed his body appropriately so that he is able to remodel his body at a steady level for the resultant breakdown that occurs with training. This concept has kept him within the “optimal window.” Four weeks prior to the start of fall classes, Paul heads to the scenic mountains to attend a running camp. Here, Paul is challenged with vastly different terrain than his body is used to. Further, his teammates and athletes from other schools are running slightly quicker than Paul is used to. The combination of challenging terrain and slightly faster paces during workouts fatigues Paul to the point where he compensates his gait pattern. The mechanical stresses acting on his body are different from those he had all summer and push him outside of the optimal window. Paul is break
ing his body down faster than he can recover. By the time camp is over, he has developed pain in his Achilles.

Paul returns home and informs his coach that he has pain that is almost too severe to allow him to run. The coach advises Paul to stop running to rest the ankle. Paul respects the advice of his coach and stops running. He also stops all other athletic activity and is determined to be 100 percent by the start of the season—just three weeks away.

Paul’s inactivity over the next few weeks helps the pain subside. He begins to lose focus and gets busy with his summer job and girlfriend. He figures that all the training he did at the beginning of the season is enough to prepare him. While rest can allow inflammation to reduce, he does nothing at all over this period of inactivity. His body is now receiving an insufficient stimulus and actually begins to decondition. The mechanical structures that make up his body actually begin to weaken, even though Paul is now symptom-free.

School is back in session and Paul joins his teammates for workouts. Since the majority of the team had been consistently training all summer long and had a successful training camp, they arrive in better shape than Paul. Paul jumps right back in and pushes things a bit too quickly. Within two weeks, the Achil- les symptoms have resumed, and he is now forced to miss the first four races of the season. He sees the school’s trainer and receives ice and electric stimulation to help reduce the swelling and his symptoms, but he’s not improving.

Does this situation sound familiar to you? If not, replace the words “high school” with “college.” Or replace the “early high school season” with your transition to 5K and 10K training after marathon season. Replace “summer job” with “career,” and swap “girlfriend” for “wife/husband.” Given that 82 percent of runners are injured, the chances that you or your runner could have auditioned for Paul’s role in this story are exceptionally high. If you were cast as Paul, what would you have done differently? Would you have rested completely? Maintained a reduced running volume? Would you have changed shoes? Would you have iced the leg more or less? Would you have done any corrective stretches or exercises while waiting for the area to heal? Cross-training? Are the answers to any of the above questions informed or based on the lore passed down through your friends? Before you can correctly answer any of these questions, it’s essential to understand microanatomy and how the tissues of the body respond to different mechanical stresses.


Jay Dicharry, MPT, SCS built his international reputation as an expert in biomechanical analysis as Director of the SPEED Clinic at the University of Virginia. He also consults for numerous footwear companies, the U.S. Air Force and USA Track and Field. He currently lives in Bend, Oregon with his family, and is associated with Rebound Physical Therapy. To find out more about Jay and “Anatomy for Runners” (including purchasing a copy), go here.

5 Responses to ““Anatomy for Runners”: Excerpt on Why Runners Get Injured by Jay Dicharry”

  1. MarkC says:


    thanks for sharing the piece and for sharing your knowledge with me over the years. NRC readers get off the blog now and order the book…..this is the foundation of all running knowledge.
    Trust me on this one.

    Dr. Mark

  2. Jim Hixson says:

    This past Friday I was talking to Dr. Greg Holtzman, the head of Washington University’s Running Clinic, and I noticed Anatomy for Runners on his desk. He said he was in the middle of it and couldn’t wait to get back to it.

  3. Ryan says:

    Read Jay’s book once and going back for a second dose. Many of our staff members have it and it is a constant source of referral for me when I’m off the sales floor. Thanks Jay and Dr. Mark for all you do for us “students”.

  4. John Binns says:

    Looks like a very interesting read. I would be very keen to review the book on my blog but just wondered if an ebook version would be available soon as I would prefer to buy this rather than print.

  5. johnnydajogger says:

    Wow! What a fantastic book. I’m going through it for the second time. Its not an easy read, lots of actual science. I hope to be able to implement his suggestions on my own. Dont just read this book like a novel. Study it and incorporate its suggestions into your training routine.

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