A shin splint – also known as medial tibial stress syndrome – is a condition that causes pain and tenderness along the inner border of the lower leg bone or the shin bone (called the tibia). This pain and tenderness are due to the inflammation of the muscles, ligaments and bone tissues attached to the shin bone.
Shin splints commonly occur after running or doing vigorous exercise. Individuals who have just started a fitness program, suddenly changed the intensity of their exercise or routine, or increased their weight-bearing exercise are likely to experience shin splints.
The abrupt load on the muscles and surrounding tissues results in overwork leading to pain and inflammation.
Are certain people more susceptible to shin splints than others?
Individuals who have one or more of the risk factors listed above may be more susceptible to shin splints than others. However, shin splints most commonly affect runners, dancers, military recruits, and athletes who have intensified their training regimen. 
What causes shin splints?
Some common causes of shin splints are:
- Intense running, especially on inclined terrain.
- Exercises or activities that require frequent sudden starts and stops, such as dancing, running, or military training.
- High-impact physical activity. Many athletes that engage in high-impact sports (ie track and field, basketball, soccer, and tennis) are most likely to develop an overuse injury. 
- Increased activity. These injuries frequently occur in individuals who suddenly increase the duration, intensity, or frequency of physical activity. This can include athletes who increase their level of training or shifting from a more inactive lifestyle to one with an exercise regimen. 
- Uneven surfaces. Running on uneven terrain– such as hills, gravel, or mud– increases the likelihood of injury. Similarly, changing the training or playing surface, like from grass to concrete, can cause a shock overload on the legs. 
- Foot structure. Individuals with flat feet or unusually high arches are more likely to develop lower leg injuries, as their foot structure interferes with how the leg muscles normally distribute the shock forces from exercise.  Similarly, using worn-out footwear with inadequate arch cushioning can put more stress on the muscles and tendons of the lower leg. 
- Foot pronation. Running or exercising with improper technique will also increase the risk of injuring the foot and leg. 
- Health history and previous conditions. Individuals who have historically had poor nutrition, vitamin deficiencies, bone health conditions, or previous leg injuries are at high risk of injury and reinjury.  This is especially true for stress fractures, as bones with altered quality or structure are more susceptible to fractures.
Since shin splints and stress fractures share many of the same symptoms, you will often need a medical professional to accurately diagnose the injury. Physicians will usually be able to determine the nature of the injury with an account of the symptoms, an assessment of the patient medical history and risk factors, and a physical examination of the injured leg.
Diagnostic imaging tests are also useful to confirm (or rule out) other possible conditions, like a stress fracture. 
During a physical examination, physicians will ask about past medical history, current work, recreational activities, medications, and other risk factors. 
Next, they will assess the lower leg, beginning with a general observation of inflammation, discoloration, pain, and other obvious changes. Then they will examine the leg in non-weight bearing and weight-bearing positions to assess the severity of the injury.
- “Shin Splints.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 17 Sept. 2019, www.mayoclinic.org/diseases-conditions/shin-splints/symptoms-causes/syc-20354105.
- Alaia, Michael J, and Stuart J Fischer. “Shin Splints – OrthoInfo – AAOS.” OrthoInfo -AAOS, Aug. 2019, orthoinfo.aaos.org/en/diseases–conditions/shin-splints.
- “Running with Shin Splints? What You Need to Know.” Orthopaedic Associates of Central Maryland, 3 Aug. 2018, www.mdbonedocs.com/running-with-shin-splints-what-you-need-to-know/.
- “Stress Fractures.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 17 Sept. 2019, www.mayoclinic.org/diseases-conditions/stress-fractures/symptoms-causes/syc-20354057.
- “Stress Fractures of the Foot and Ankle – OrthoInfo – AAOS.” OrthoInfo – AAOS, Mar. 2015, orthoinfo.aaos.org/en/diseases–conditions/stress-fractures-of-the-foot-and-ankle/.
- “Stress Fractures: Causes, Symptoms, Tests & Treatment.” Cleveland Clinic, 12 May 2020, my.clevelandclinic.org/health/diseases/15841-stress-fractures.
- Hecht, Marjorie. “7 Shin Splint Stretches for Recovery and Prevention.” Edited by Gregory Minnis, Healthline, 6 Mar. 2019, www.healthline.com/health/shin-splint-stretches.
Elizabeth Miclau is an undergraduate at Harvard College, planning to pursue a concentration in life sciences or sociology. As a member of both Puerto Rico’s National Diving Team and Harvard’s Women’s Varsity Swimming and Diving Team, she has a strong background in elite athletics. In the past year, she has contributed to several journal publications and peer-review-funded research projects.