Shin Splints in Runners

 

Cause of Shin Splints in Runners

Shin splints are an overload condition of the muscles on the front of the leg. The muscles on the front of the leg have to work to slow down the foot when striking the ground. When running at slower speeds, the muscles on the front of the leg have to work harder to decrease the force of the foot landing on the ground. 

Risk Factors for Shin Splints 

Risk factors for the development of shin splints include: 

  • Increased body mass index (BMI)
    While actually a poor indication of body fat, a higher BMI suggests there is move force for the foot to absorb with each stride.  
  • Increased navicular drop
    The navicular is a small bone that makes up the inside arch. An increased navicular drop is an indication of a smaller arch height. 
  • Increased plantarflexion range of motion
    Plantarflexion is when the toes point away from you. It is unclear why increased plantarflexion increases the risk of shin splints, but may have something to do with the smaller arch height.
  • Increased hip external rotation range of motion
    Again, it is unclear why increased hip external rotation is a risk factor for shin splints. 

Tibial Stress Fractures in Runners

A tibial stress fracture occurs when the bone is unable to tolerate the loads placed on it. With repetitive loads, as in running, the loads lead to small fractures in the bone. 

Treatment of Shin Splints in Runners

At home, self myofascial release therapies can be used to decrease the pain and tightness experienced with shin splints. These often include using either a lacrosse ball or a foam roller over the muscles on the lower leg. 

A combination of soft tissue work to the anterior and posterior tibialis muscles along with joint mobilizations to the ankle joint can help decrease the pain of shin splints in the clinic. Soft tissue work can be performed by hand (pin and stretch or myofascial release technique) or by instrument (Graston technique). Kinesiology tape, such as RockTape, can also be used to stimulate the receptors in the skin which decreases pain (think of rubbing your elbow after you hit it on a wall). 

The rehab program for shin splints involves strengthening the lower leg muscles, especially during eccentric movements. Eccentric movements are when the muscle lengthens as it contracts (often called negatives). This is the type of contraction the anterior tibialis muscle does when lowering the foot towards the ground with running. 

Other treatment options include changing running cadence and shoe wear. Increasing the running cadence will reduce the force on the muscles of the front of the leg. Speeding up the running cadence shifts foot strike from a heel strike to a mid-foot or toe strike instead. As for shoe wear, if the running shoe has lost it's shock absorption ability, then the force is absorbed in the muscles instead.