SHIN SPLINTS: THE LOWER LEG SILENT KILLER


MEDIAL TIBIAL STRESS SYNDROME (“SHIN SPLINTS”)


With over four hundred thousand high school athletes getting ready to compete in cross country this year, athletes have to remain vigilant when it comes to staying injury free. With many high schools having their first races in the books already, coaches and athletes are starting to ramp up the volume and intensity. The increase in activity may be ok for some athletes but what about athletes that are new to the sport or are biomechanically dysfunctional?


Most athletes who have run cross country or track, have had at one point what many refer to as “shin splints.” Shin splints or what I will refer to as medial tibial stress syndrome (MTTS), its medical name, is one of the most common lower leg injuries in runners. [1]


The goal of this article is to educate runners and coaches alike on the importance of As the old adage goes “Just because you can do something, doesn’t mean you should.” We all would be mindful to remember that saying when it comes to training.


WHAT IS MTSS?


MTSS is characterized by pain along the inner part of the tibia (“shin bone”) that occurs during exercise and sometimes after the cessation of the activity. [2]. Although not as common, some athletes experience posterior medial shin splints, which is pain on the back inside of the tibia [4]. The tibia is the large bone in the front of your lower leg. For the purposes of this article, I will focus on MTTS since this is much more common among runners.


WHAT ARE THE SYMPTOMS OF MTSS?


The most common complaint of patients with MTSS is vague, diffuse pain of the lower extremity, along the middle-distal tibia associated with exertion [3]. I have heard athletes tell me so many times, “It only hurts when I first start running.” Never ever run through pain. Now repeat that 100 times and repeat it 1000 more times.


In the game Monopoly, this would be the moment when you pick up the Community Chest card and think it is about to be something good but then you start reading and it states, “Go directly to jail. Do not pass Go, do not collect $200”. Stop everything you are doing because the check engine light is on. Pain is a sign to the body to stop whatever you are doing. It is our version of a car’s check engine light. You can ignore the light and keep driving until the engine blows up or you can check under the hood and get it fixed. One is way more costly than the other.

Athletes with MTTS may experience some of the following symptoms:

  • Sharp pain or dull throbbing pain

  • Tenderness or pain along the medial area of the leg

  • Pain gets worse during exercise

  • Sore to the touch

  • Pain towards the middle or bottom of the shin

If you are experiencing any of these symptoms, PLEASE REST!

Here is a test that can be used to see if it is a shin splint or possibly a stress fracture

If the symptoms do not get better with rest and treatment then you may have a stress fracture and will want to see a medical professional.


CAUSES OF MTSS?


The most common cause for MTSS is a training error, known as “too much, too fast” [15,16]. Coaches and athletes have all done “too much, too fast” at one time or another. A sudden increase in frequency, intensity or volume can cause MTSS in runners. [15,16]. Doing all of your running on hard or uneven surfaces is a common risk factor as well.


Studies show that the primary cause of MTSS is likely caused by a bone stress reaction of the tibial cortex as a result of tibial bending and subsequent bone remodelling. due to the repetitive pull of the muscles on the periosteum (outer layer of the bone in which muscles attach) of the inner part of the tibia. [5,6]. The repetitive and excessive amounts of force from running and jumping cause the muscle surrounding the tibia swell and become inflamed. [5,6]. This inflammation can lead to pain if not treated early.



WHAT ARE SOME COMMON RISK FACTORS?


MTSS is typically associated with biomechanical irregularities of the leg [9]. Many of the risk factors for MTSS are preventable but trying to control all of them is impossible. This list below is not meant to be exhaustive.


  • Body Mass Index

  • A BMI > 20.2 has been shown to be an intrinsic factor for cross country runners [7].

  • Bone geometry

  • Studies have shown that there is a clear association between smaller tibial bones and tibial stress injuries. [8-11].

  • Hip External Range of motion (ROM)

  • Both tightness and hypermobility can increase tibial loading during activity or alter the angle of the femoral neck at the hip joint, thereby increasing torque on the lower leg. [3].

  • Muscle Imbalance and Tightness

  • Tightness of the triceps surae (gastrocnemius, soleus and plantaris muscles) is associated with MTSS. [3]. Athletes with weaker and leaner calves are more prone to muscle fatigue in the calves, which can lead to poor running mechanics and strain on the shin. [3].

  • Weak Core

  • A strong core and hips are important in maintaining a strong kinematic chain. Weak core can lead to biomechanical issues which in turn can lead to injury. If the core is weak the body cannot efficiently transfer the force from one part of the body to another and force starts to “leak” into areas that it should not be.

  • Training History

  • Running experience is strongly associated with the development of shin pain. [13]. Newer runners tend to get shin pain more than runners that have been running for years. This could possibly be to the lower leg muscles becoming more conditioning over the years.

  • Pronation

  • Pronation of the subtalar joint foot is one of the most consistently found risk factors in MTSS [2].

  • Individuals with flat feet are more prone to develop MTTS due to foot rolling inward when it lands causing the tibia to twist, which in turn causes stress on the lower leg.

  • Individuals with high arches are also prone to MTTS due to their feet being poor shock absorbers.

  • Sex

  • Females are typically more likely to develop MTTS than males. [2, 12].

  • Female runners typically have a delayed onset of menstruation which can lead to lower bone density in the tibia. [14].

  • No long term studies but other risk factors may include the following:

  • Old shoes

  • Changing to different shoes

  • Orthotics may help although studies are inconclusive

  • Change of training terrain

  • Running intensity


HOW TO TREAT MTSS?


Rest


While it may not be ideal for many athletes, rest is probably the most well known and important treatment of MTSS. [3]. Most athletes do not want to rest and feel that they are missing out on their sport. Cryotherapy such as ice bags on the shins after training may help with inflammation. During this period cross training is most likely the athlete’s best friend, as the athlete does not want to lose aerobic fitness while allowing for the shins to recover.


Change The Training


I feel this may be the most neglected part of many injury recovery programs. The athlete comes back healthy and feeling good but fails to address the underlying issue that caused MTSS. The athlete cannot “jump” back at the same level or mileage. There must be a gradual increase in mileage and whatever caused the biomechanical problems needs to be addressed before the athlete gets injured again. [3]. Athletes can continue to cross train some days while running some days to allow the body to fully adjust to the training. A plan might look something like cutting running by 50% while swimming or biking on the other days.


Lower Leg Strengthening


I am a huge advocate of lower leg strengthening and stretching. In my experience most runners' calves are too tight and too weak. Most athletes do not have to worry about a lack of joint stiffness when it comes to the ankle area. This can be done by doing leg raises on a stair or other elevated area. The purpose should be to work the eccentric part of the calf while working the inner and outer parts as well to ensure that the entire leg is strengthened and stretched.


Manual Techniques