Medial tibial stress syndrome, more commonly known as shin splints, refers to lower leg pain below the knee on the front outside part of the shin (anterior shin splints), or the inside of the leg (medial shin splints). They’re common among runners, but as one of the most frequent injuries in sports they can afflict athletes of any discipline.
Symptoms of shin splints
Athletes will typically feel an aching pain on the inside of the shin when they finish running or exercising. If left untreated, the pain will develop to more of a burning sensation, and can provide discomfort in the middle of a workout. It’s important to distinguish shin splints from other conditions, such as compartment syndrome—a swelling of muscles within a closed compartment. This condition creates pain on the outside of the lower leg, and typically requires special techniques such as surgical “decompression” to diagnose. Lower leg pain may also be a sign of a stress fracture (an incomplete crack in the bone), which may require an MRI to diagnose—especially in cases of severe shin splints in small areas. Pain from shin splints is usually more generalized than that of a stress fracture, and they also feel worse when you wake up in the morning because the soft tissue has tightened during sleep. Bone, on the other hand, has had the opportunity to rest, so stress fractures won’t feel so bad in the a.m.
That’s great—but what the heck is a shin splint?
For a long time sports scientists have disagreed as to what exactly a spin splint is, with theories ranging from muscle inflammation to small muscle tears in muscles that have pulled away from the bone. Yet an article in Runners Connect relays information from anatomic studies that point towards overuse injuries to the tibia (the larger bone in your shin) as a more likely definition.
“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. 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.”
The tibia bears a lot of your bodyweight, so when you run (particularly on hard surfaces) the bone bends slightly backwards as your foot strikes the ground. This puts a lot of shear force on the medial side of the shin.
Other causes of shin splints include:
Flat feet, rigid arches, over-pronation (ankles roll inward on impact)
Your foot and ankle should move slightly inwards when you walk or run, but excessive inwards movement is deemed as over-pronation. This, along with flat feet and rigid arches, are mechanical faults that can cause uneven pressure distribution on the lower legs.
Poor rehab from prior shin splints
Coming back to intense workouts without fully recovering from a previous bout of shin splints raises the risk of having recurring issues with them.
Sharp increases in training intensity, duration and volume
The bodies of more seasoned athletes and runners have adapted to the demands of intense training and long runs, so much so that their bodies know how to rebuild the tibia following the stress that’s placed on it. Newer athletes are more susceptible to developing shin splints since their bone tissue isn’t as adapted to the stressors from running and other high-impact activities.
Downhill running places your foot in a plantar-flexed position (toes pointed down), so there’s additional stress placed on the front of your shin when your foot hits the ground, rather than being distributed evenly across the foot.
Treatment options for shin splints
The first action you take if you’re suffering from shin splints is to rest, and apply ice to decrease local inflammation (though ice should never be directly applied to the skin—wrap it in a thin towel instead).
You should also look to increase your stride frequency when running by about 10%. Your stride frequency is the rate at which you can move your legs when running. It can be measured as strides per minute, per hour, or per distance (100m, 400m, etc.). Increasing stride frequency reduces the impact the tibia has to absorb upon each foot strike with the ground (since you’re increasing your stride frequency, you’re spending more time in the air as you’re looking to run faster, since time on the ground is wasted).
Many experts also advocate the use of proper/new footwear. New shoes can also help treat shin splints as old shoes may not properly absorb shock and have arch supports that have been flattened out.
Strengthening the muscles in your lower legs and reducing tightness is also important. Boosting the strength of the calves and making sure your Achilles’ tendon is supple helps to support a stronger tibia, which makes it better equipped to handle the shock from repeated foot strikes. Low calf strength is linked to high rates of shin splints in runners, so make sure that you don’t skip leg day—and strengthen the leg in its entirety. Some calf-strengthening exercises include:
This is a simple and quick drill that is easy to perform. Simply place your toes on a slight incline (like two 5lb plates) and move into dorsiflexion by bending your knees. Increase the incline as you progress.
-Self myofascial release on the foam roller.
Grab a foam roller (the harder the better) and sit on the ground. Place one leg on the roller, just above the ankle, and rest the base of the heel of your free leg on your toes. Roll up and down the entire length of your calf for 1 minute. If you hit a tender spot, pause and focus on this area for 10-20 seconds.
Stand on the balls of your feet on some stairs or a block. Use the railing or the wall for support. Keep your legs straight and allow your heels to drop down towards the ground. Slowly raise the heels up by pressing into the block with your toes. Repeat for 10-20 reps.
This is a drill I picked up from my days playing basketball to improve my vertical jump. Stand on your tiptoes, legs straight, and hop 2-3 inches off the ground. Land on your tiptoes, and hop again. This is a low impact drill that builds strength in the calves, and incidentally helps with your double-under technique by forcing you to stay on your toes. Repeat for sets of 50-100 (you’ll get through them quickly).