Shin Splints Explained for All Runners and Good News for Sufferers

This is Camille Herron’s second post for the Natural Running Center. Her first on how she became a world-class marathoner by adopting minimalism was exceptionally well-received by readers. Ms. Herron, who has a Masters Degree in Exercise Science, is the newest member of NRC’s advisory board. We would be remiss if we didn’t mention that seven weeks after placing 26th at the  2012 U.S. Olympic Marathon Trials, with a PR of  2:37:14, she won The Woodlands Marathon in 2:37:18. — NRC

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Shin Splints

by Camille Herron

Introduction

I had anterior shin pain on and off again for the first 8 years (1995-2003) of being a runner. I had what is commonly referred to as “shin splints”, or medial tibial stress syndrome. Fortunately, my shinsplints never developed into a stress fracture– just inflammation of the periosteum (the sheath surrounding the bone).  I had tender, crunchy scar tissue I could feel along my shins (mainly my right leg). I tried different shoes (to go along with my orthotics), creams, anti-inflammatories, massage, ice massage, and taping techniques. I actually found I could tape my shins a certain way, almost like what Kinesiotape does today by moving the muscle off the irritated nerve. I also wondered whether my shin pain was due to some sort of muscle imbalance, so I would do exercises like calf raises, stretching, and dorsiflexion exercises (which I don’t remember if these exercises helped or not).

What causes shin pain?

It wasn’t until I started taking my Physics and Biomechanics courses as an undergrad that I really started understanding the mechanics of the human body. I had also taken Anatomy and Kinesiology my sophomore year, which went over where muscles originate and insert on bones and their actions…. understanding this is highly valuable for understanding how any injury occurs! There’s different types of “shin splints”, whether anterior, posterior, or even in relation to the fibula– the location says a lot about which muscle and action is the culprit. If you do a simple Google search on “shinsplints”, you will find a massive load of information, including the Wikipedia page .

The best reference I had at the time was Timothy Noakes’s Lore of Running. This is a book every runner should own.  There’s a lot of factors on why some people are more predisposed to this condition than others. I’ll point out the factors I felt pertained to me:

1. Shin splints is most often a beginner’s injury. This doesn’t always imply someone who’s new to running– it could be that you’ve taken time off from running and you’re starting back. As Dr. Noakes points out on pg. 807, he says this injury largely affects high school track athletes who go from doing little to no training, to spending a month preparing for their first track meet. They do “too much, too soon” for the body/bones/muscles and often under less-than-ideal conditions (running in one direction around a track and/or on unforgiving surfaces). They’ve usually been running for 5-12 weeks, sometimes to lose weight (heavier than ideal), and progress too rapidly. The issue tends to impact more women than men, which might say something about our anatomical build and muscle strength/weaknesses.

Muscles act as shock absorbers that attenuate the stress/impact of running. When a muscles is weak, it’s less fatigue resistant. As the muscle gets tired, more stress is transferred to the bone. Beginning runners likely do not have adequate muscle strength and foot and leg control/coordination to resist the stress and fatigue from the impact of running. Because of doing “too much too soon”, the muscles are overused. The stress and inflammation exceeds the body’s ability to repair and rebuild itself. You’ll develop the crunchy scar tissue along the tibia, as the body tries to repair itself, and possibly have nerve irritation.

As Dr. Noakes points out, he advocates walking, before you begin running, to get the muscles and bones aquainted to the impact/weight bearing.

Given the above, there’s lots of information out there on exercises and treatments for shin pain. However, the problem largely lies in doing “too much too soon”– if you allow the muscles and bones to adapt (and get stronger) at an appropriate rate, the problem should resolve itself. If the problem becomes chronic, continue reading on what the underlying problem could be

2. Shin pain is directly due to a biomechanical incompatibility/imbalance between your feet and shoes. First off, many of the muscles in the lower leg originate on the tibia or fibula and then insert on bones in the feet. It’s the [over]action of the foot (possibly due to a mismatch between foot-shoe) that can impact the amount of stress these muscles receive, and ultimately the stress is transferred to the bone (whether in the lower leg or foot).

Dr. Noakes points out how shin pain is most often associated with overpronation, meaning the foot is hypermobile (flat foot). On this note, I’d like to quote Dr. Noakes (3rd edition, pg. 497):

“It seems that runners alter their gaits and muscle activation patterns (Komi et al., 1987) when running in harder shoes or when running barefoot. Thus, the degree of pronation is reduced when one runs barefoot (Frederick, 1986; L.S. Smith et al., 1986), a reduction due to changes in running patterns….. (pg. 500) The major changes that have occurred in the patterns of running injuries since 1970 have been… increases in the incidence of shinsplints (from 10 to 18%) ….The reason incidences of the other injuries have risen may be due, as Cavanagh (1980) suggested, to the introduction of softer running shoes, which control pronation rather poorly…. (pg. 507) Hard shoes are those designed to limit ankle pronation, which are normally prescribed for the treatment of runner’s knee and shinplints. Indeed, it is not uncommon for an athlete treated too enthusiastically for either runner’s knee or shinsplints to return some weeks later with the initial injury cured but with an iliotibial band friction syndrome that has been caused by shoes and orthotics that restricted ankle pronation too effectively.“

We all pronate to different degrees to absorb shock during midstance. There’s nothing wrong with this. You actually pronate most ideally, for you, while barefoot (and after developing proper foot and lower leg strength). It’s shoes that cause some people to over-pronate, leading to injuries such as runner’s knee and shinsplints. Why? Because the shoes are too soft/unstable, making the feet hypermobile, and overusing the muscles in the lower leg. Then, shoe companies have to “correct” the defects of the shoe by making the shoe firmer with “motion control” features, to ultimately limit the mobility of the feet; and/or, a podiatrist may prescribe orthotics to limit the mobility of the feet. While this may correct the shin pain, as Dr. Noakes points out, it may over-correct and lead to a problem elsewhere, like the IT band. Ironically, this is exactly what I dealt with in 2003, after switching from cushioned Nike Pegasus (with orthotics) to Mizuno Wave Riders (with orthotics). I wish I had read Dr. Noakes’s insight sooner!!!

Given what happened above, this is what made me decide to ditch the trainers and orthotics and begin training in racing flats in December 2003.  I figured they were firm (to provide a more stable “base”), but would allow me to use my feet appropriately to absorb the shock, rather than transferring the stress up the leg (~to my IT band). In a racing flat, having less cushioning and being closer to the ground/lower center of gravity), you get the “stability” of a stability/motion control shoe…. without debilitating and “correcting” the feet. The feet are fine, as is…. and need to be able to “do their thing” for the body to “be in balance” and able to absorb shock appropriately. As I mentioned in my post about transitioning to racing flats, it took about 3 months for my lower legs/feet/ankles to adapt and get stronger. I ended up curing both my longtime problem with shinsplints and also my recent incidence of IT Band Syndrome.

The past 8 years, the only time I had a flareup with shin pain was when Brooks changed from the T5s to the T6s. My legs were well-adapted to the T5s, and it seemed that whatever changed with the T6s (Cushioning? Upper? Sole? Curved last?)…. it stressed my lower legs differently, and they had to adapt. I wanted to share this because even a subtle change in shoes, going from one model to another or even an update to a model you normally wear, can impact the stress on the legs. Be mindful if you make a change in anything…. as the body must adapt to that change.

How do you distinguish between shin splints and a stress fracture?

With my background in Bone Biology, I get asked this question quite frequently. Unfortunately, shin splints can develop into a stress fracture if you don’t allow for adequate rest. However, what I’d like to point out is that shinsplints is often either a short term inflammation that goes away (if you’re a beginner and the bones/muscles are simply adapting to the stress)….or it’s a chronic pain/inflammation of the periosteum (pain usually along the whole tibia where the muscle inserts), which you can train through and often manage (as I did for 8 years). If it’s chronic, it’s most often biomechanically related.

A stress fracture is usually sharp, localized-to-one-spot, sudden pain– you absolutely can’t train through it. What I found is I could hop just fine on my leg when I had shinsplints, but I absolutely couldn’t hop on the leg when I had my stress fractures (although none of my stress fractures were in the tibia either). If I remember correctly, my shin splints were often at their worst during the first part of the run, and would get to feeling better as I kept running. With my stress fractures, the pain would get progressively worse, to the point where I couldn’t run. With a stress fracture, you may feel throbbing pain in the tibia, even at rest.

What you also have to understand is that our bones are constantly in a state of remodeling, being broken down and built back up. There’s times I’ve felt sharp pains in my body, and knowing what I know about bone…. I take that as a sign to back off on the intensity for a few days and jog easy. You will often keep a stress fracture from occurring (and let the bone rebuild) if you back off the intensity.

Conclusion

Overall, there are numerous factors involved with shin splints. I highly recommend reading Lore of Running if you’re personally dealing with this problem. What I’ve shared above is purely my own personal experience and thoughts on the etiology of what caused my own shin pain. I am not a health professional either– if this issue is plaguing you, seek out proper medical advice, hopefully someone who understands runners. Hope what I’ve shared above is helpful.

This article originally appeared on Ms. Herron’s website.