The Ultimate Guide to Shin Splints for Runners
Medial tibial stress syndrome, more commonly referred to as “shin splints,” is probably the most universally-known running injury.
Shin splints classically present as an aching pain on the inside of the shin, near the border of the tibia and the calf muscles. The area will often be sore when poked or prodded, and will initially hurt at the end of a run. As the injury progresses, the pain will sometimes move to a more sharp, burning sensation, and may hurt during your entire run, or even when just walking around.
Shin injuries can be diffuse, spreading out over many inches along the length of the tibia, or be localized to a small area less than two inches long. Serious cases of medial tibial stress syndrome, especially when localized to a small area, need to be distinguished from a tibial stress fracture, which can be accomplished with an MRI or a bone scan ordered by an orthopedist or podiatrist.
While not the most common running injury, medial tibial stress syndrome, or MTSS, still accounts for about 5-6% of all total injuries.1, 2
Unlike many injuries, which seem to strike at runners of all fitness levels, shin splints are much more common among less experienced athletes. In a typical three-month high school cross country season, for example, between 12 and 15% of the runners on a typical team will suffer from shin splints.3, 4
Woman are 2-3 times more likely to develop shin problems than men.5 Additionally, among studies of military recruits, soldiers and sailors in poor physical condition (who likely have little history of athletic activity) are much more likely to suffer from shin splints.6
In contrast, very few experienced runners have to deal with shin pain on a regular basis. Understanding the mechanism of injury can help explain why.
Causes of shin splints and what makes the injury worse
For a long time, shin splints were postulated to be a soft tissue injury. Many of the muscles of the lower leg, including the calves and the smaller muscles above the ankle, insert along the tibia. It was proposed that tightness or weakness of these muscles caused them to tug at their insertion point, irritating the periosteum, a thin, skin-like structure that envelopes the tibia itself. This distinguished medial tibial stress syndrome from tibial stress fractures and stress reactions, which are indisputably true bone injuries.
However, more precise anatomic studies have demonstrated that the muscular insertions blamed for causing shin pain do not correspond to the location of the injury;7 instead, advanced medical imaging studies have illustrated that all overuse injuries to the tibia, from mild cases of “shin splints” to true stress fractures, exist on a spectrum of bony injuries.
The most telling fact is localized bone density: in CT scans of the tibias of runners with shin pain, pockets of low bone density appear at the location of pain. After these runners have recovered, these pockets of low density have disappeared.8 Additionally, runners with tibial stress fractures often have larger areas of lowered bone density around the fracture.
With this new information, scientists now hypothesize that the root cause of shin splints is repeated stress to the bone during running, caused not by straight-on impact, but a slight bending of the bone when it is loaded.
Much like a beam on a bridge or in a skyscraper bows slightly when it’s supporting a lot of weight, your tibia bends backwards slightly on impact with the ground, putting compressive forces on the medial side of the bone.
In healthy runners, the bone stress after a long, hard run is not a problem. The body responds to the stress on the bone by remodeling the tibia to be stronger and thicker. This is why shin problems are more common in less-experienced runners: their bone has not yet adapted to the stresses of a high-impact activity like running.
Unfortunately, this remodeling process takes several weeks to a few months to complete, and there is a period where the bone is actually more vulnerable to damage.
Just like remodeling your house entails tearing out some walls before adding new construction, your body has to tear out some of the old bone tissue before strengthening it. As a result, having a small tibia or weak bones puts you at an increased risk for shin splints, since your weakened tibia is more vulnerable to injury when it is remodeling its bone structure.
Research backed treatment options for shin splints
The current theories for treating and preventing medial tibial stress syndrome revolve around reducing the relative amount of stress on the tibia. Reducing impact and tibial loading, strengthening the supporting muscles, and strengthening the bone itself should all lower your risk of developing shin splints and may also speed recovery.
Unlike some other running injuries, there are no solidly vetted treatment protocols. Rather, what follows is an extension of work on the precipitating factors for shin splints.
- Reducing impact loading should be a priority for anyone with shin problems. Increasing your stride frequency by about 10% (bringing it close to 180 steps per minute or more) will markedly decrease the impact your tibia has to absorb each time your foot strikes the ground.9
- You might think that running on a softer surface or in more cushioned shoes would also reduce impact, but because the leg adjusts its stiffness to compensate, the actual forces going into the ground hardly change at all. In fact, there is even a little evidence that running in thinner shoes on a harder surface might be a better idea, since it lowers your leg stiffness!10
- Strengthening your calf and shin muscles might absorb some shock, reducing the strain on your tibia, but more importantly, will lead to a stronger tibia in response to the increased muscular strength and size. It’s been demonstrated that female runners with a small calf circumference have a much higher risk of developing a tibial stress fracture,11 so it is no surprise that runners with shin splints have poor calf strength.12
While there is no set protocol as of yet for increasing calf strength, a program of standing calf raises to fatigue twice daily will go a long ways towards building your lower leg strength. There is also a lower-leg-strengthening routine we’ve developed, outlined below. These can also be done once or twice daily, and ought to be done barefoot on grass if possible.
1. Heel walk x 15 each foot
2. Toe walk x 15 each foot
3. Feet out walk x 15 each foot
4. Feet in walk x 15 each foot
5. Ankle in walk x 10 each foot
6. Ankle out walk x 10 each foot
7. Eccentric calf straight leg x 25 each foot
8. Eccentric calf bent leg x 25 each foot
12. Shin exercises with thera band x 10 each foot
Other possible treatment options for shin splints
With respect to orthotics, a few studies have demonstrated some success in using custom shoe inserts to treat shin splints.13 This is a good sign, as many other injuries respond poorly to treatment with orthotics. Custom inserts might shift the distribution of pressure on the bottom of the foot, which may be associated with shin pain.
Nevertheless, orthotics are not a panacea and shouldn’t be your only treatment method. Many runners find good success with over-the-counter semi-rigid orthotics like the SuperFeet or PowerStep insoles, and these are much cheaper than custom orthotics, so give them a shot first.
Among more exotic treatments, extracorporeal shockwave therapy (ESWT) has emerged in recent years as a treatment possibility. In ESWT, shockwaves are applied directly to the tibia to encourage new bone growth. Only one study has tested ESWT, and it suffered from some design flaws, but it showed a significant reduction in recovery time.14 ESWT treatment may be expensive and difficult to find, and its experimental evidence is still not up to snuff.
Outline of Treatment for Shin Splints
These are methods that are fairly simple, inexpensive, and can be done on your own at home.
- Work to reduce stress on the tibia by increasing your stride frequency by 10% or so to avoid overstriding and excessive impact.
- Ice your shin using ice cups several times a day, and always after running
- Calf raises starting with one set of 20 repeats and building to three sets of 20 (or more), twice per day.
- Our preventive foot drill routine. Once per day:
- 1. Heel walk x 15 each foot
- 2. Toe walk x 15 each foot
- 3. Feet out walk x 15 each foot
- 4. Feet in walk x 15 each foot
- 5. Ankle in walk x 10 each foot
- 6. Ankle out walk x 10 each foot
- 7. Eccentric calf straight leg x 25 each foot
- 8. Eccentric calf bent leg x 25 each foot
- 12. Shin exercises with thera band x 10 each foot
- Modify your training so you don’t put as much stress on your tibia. Reducing mileage, intensity, and duration of your runs will all help. Remember, it can take several weeks to a few months for the tibia to heal.
These are treatments with more cost and less certainty about outcomes, but may prove useful in recalcitrant cases.
- Custom shoe orthotics or over-the-counter semi-rigid orthotics (SuperFeet, PowerStep) may be able to modify how forces are transmitted up the tibia, though this is unproven. Many runners find that orthotics greatly improve their shin pain, but possibly just as many find that they are no help.
- Consider running in a thinner, firmer shoe on a harder surface. While the actual benefit for people with shin pain is as-of-yet unproven, biomechanics research has linked soft surfaces and soft shoes with higher leg stiffness, which is itself connected to higher shocks going up the tibia on impact.
- Also consider taking a calcium/vitamin D supplement with 200% of your RDV of both. One study found that doing so reduces the risk of tibial stress fractures by 25%. Since MTSS is on the same “injury spectrum” as a tibial stress fracture, it’s possible that supplementation can help prevent medial tibial stress syndrome too.15
- If conservative treatments don’t help, you also should be evaluated by a doctor for a tibial stress fracture. X-rays are very inaccurate for diagnosing stress fractures, so your doctor should use either an MRI or a bone scan. MRIs are slightly more accurate and allow your doctor to get a better idea of the severity of the injury, so they are generally the preferable imaging technique.
Return to running
You will need to modify your training program to allow your body time to strengthen your shin bone.
Mild cases of shin splints may only require modifying your running form and doing some lower leg strength, but more serious cases will require at least a few weeks off. Keep in mind that shin splints are the same type of injury as a stress fracture, so if you feel like your shin injury is getting worse, you should not continue to run on it.
While many coaches recommend that a “10% rule” for increasing mileage is best to avoid injury, the dynamics of the tibia’s healing mechanism suggest that perhaps a stress/adaptation cycle would be better. So, instead of increasing mileage every single week by 10%, you might increase by 10% for three weeks, then take a “down week” to allow your tibia to recover (ex. 40mi-45-50-40-50…).
Good luck with your shin splints. Let us know in the comments section if you have any helpful remedies or if you have questions we can answer.
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12. Madeley, L. T.; Munteanu, S. E.; Bonanno, D. R., Endurance of the ankle joint plantar flexor muscles in athletes with medial tibial stress syndrome: A case-control study. Journal of Science and Medicine in Sport 2007, 10 (6), 356-362.
13. Beck, B. R., Tibial Stress Injuires-An Aetiological Review for the Purposes of Guiding Management. Sports Medicine 1998, 26 (4), 265-279.
14. Moen, M. H.; Rayer, S.; Schipper, M.; Schmikli, S.; Weir, A.; Tol, J. L.; Backx, F. J. G., Shockwave treatment for medial tibial stress syndrome in athletes; a prospective controlled study. British Journal of Sports Medicine 2011, 46 (4), 253-257.
15. Lappe, J.; Cullen, D.; Haynatzki, G.; Recker, R.; Ahlf, R.; Thompson, K., Calcium and vitamin d supplementation decreases incidence of stress fractures in female navy recruits. Journal of Bone and Mineral Research 2008, 23 (5), 741-749.