WHAT ARE SHIN SPLINTS?
Shin Splints is a catch-all term that commonly refers to runners suffering from pain along the medial tibia (inside shin). Medial Tibial Stress Syndrome (Shin Splints) is one of the most common running musculoskeletal injuries affecting up to 20% of runners. Although it is one of the most common injuries, there can be many causes for the pain.
The main symptom is dull pain at the lower two thirds of the back inside border of the shin, but can also be on the front outside portion of the lower leg. The pain is non-focal but extends over at least 5 cm.
To better understand the causes of shin splints, it is important to have a basic understanding of the anatomy of your lower leg.
Anterior (front): this compartment contains the tibialis anterior muscle, the extensor hallucis longus, the extensor digitorum longus and the peroneus tertius.
The tibialis anterior dorsiflexes (lifts up) the ankle and inverts the foot.
The extensor hallucis longus extends the great toe.
The extensor digitorum longus extends the other toes and assists in eversion as does the peroneus tertius.
Deep posterior (back): this contains the flexor digitorum longus, the tibialis posterior and the flexor hallucis longus.
The tibialis posterior plantar flexes (curls your foot downward) and inverts the foot.
The others are predominantly toe flexors (curls your toes downward).
These muscles are "sandwiched" between your other calf muscles (gastrocnemius and soleus) and the tibia (shin bone).
The three most common causes of shin splints are:
Improper running form
Rapid Increase in Training
Improper Running Form: This is the number 1 cause of shin splints that we see. Let's look at how improper running form can cause shin splints.
Notice how the runner has their foot flexed upward, the anterior (front) muscles contract to lift the foot up and the heel contacts the ground. This causes high impact forces into the flexed anterior muscles. As the foot comes down in a slapping motion, the posterior (rear) muscles of the lower legs are placed under heavy strain and shock trauma to try and stabilize the foot and lower leg. This overworking of the lower leg's anterior and posterior muscle groups is what can be the major cause of shin splints.
Rapid Increase in Training: Shin splints is most common with running and jumping athletes who have made training errors, especially when they overload or when they run too fast for their potential. This injury can also be related to changes in the training program, such as an increase in distance, intensity and duration.
Improper Footwear: Running on a hard or uneven surface with worn-out or improper running shoes (poor shock absorbing capacity) could be one of the factors related to shin splints. Running specific shoes are made with higher quality materials to withstand the pressures of running. Did you know that at just a jogging pace we place 3-4 times our body weight in pressure on our joints and shoes? Proper running shoes will help dissipate these forces and protect your body.
Gender. Women have an increased risk to incur stress fractures, especially with this syndrome. This is due to nutrional, hormonal and biomechanical abnormalities.
Obesity. Individuals who are overweight are more susceptible to getting this syndrome. Therefore it is important that people who are overweight, combine their exercise with a diet or try to lose weight before starting therapy or a training program. These people, along with poor conditioned individuals, should always slowly increase their training level
Cold Weather. Hardened surfaces caused by colder conditions put extra stress with each footstrike of the ground. These greater impact forces wreak havoc on the feet and lower legs leading to conditions such as plantar fasciitis, Achilles tendinitis and shin splints. Be sure to properly warm up before you begin your run by engaging in simple dynamic stretching to warm the muscles and increase flexibility.
Ice the affected area.
IMPROVE RUNNING FORM
Over-striding is one of the biggest causes of shin splints. Click here to see our in-depth article on how to correct over-striding. An increase in your cadence of as little as 5% has been shown to vastly reduce the risk of shin splints. In the image below we can see on the left how the runner landed in front of his center of balance, foot flexed, on a straight leg. With just a 5% increase in cadence cued by a metronome, the runner landed much closer to their center of gravity on more of a bent knee.
PROPER TRAINING PLAN
It is very important for runners to be patient with themselves. We all want results now. Or for most of us our worst enemy is our past, knowing what we USED to be able to do and thinking that we still can do it. It is essential that runners ease into their training plans and slowly build, following guidelines such as the 10% rule.
Running specific shoes are made with higher quality materials to withstand the pressures of running. Did you know that at just a jogging pace we place 3-4 times our body weight in pressure on our joints and shoes? Proper running shoes will help dissipate these forces and protect your body. Your local run specialty store can help educate you on proper footwear and help you find what shoe would be best for your individual needs.
*Always consult with your medical professional. We do not claim to be medical professionals, these are observations of things that we have seen to work in our own experience. These are here for your own personal knowledge and study not for any medical diagnosis.
Kaplan, A. (n.d.). In Physiopedia. Retrieved January 31, 2020 from https://www.physio-pedia.com/Iliotibial_Band_Syndrome
Mayo Clinic Staff (2019, January 14). Shin Splints: A Runner's Worst Nightmare. Retrieved from https://www.physiospot.com/opinion/shin-splints-a-runners-worst-nightmare/
Way, D. (2016, November 29). Winter Running Injuries to Watch Out for. Retrieved from https://runningmagazine.ca/sections/training/injuries/winter-running-injuries-watch/