Friday, May 13, 2016

Clarifying "Shin Splints"

By Dr. Greg Lusk, DC

With warmer temperatures we will notice an emergence of outdoor running enthusiasts.  Unfortunately for some, the efforts towards a more regular fitness habit will be plagued by the development of lower leg pain that may force a hiatus.  Lower leg pain experienced while running, but not exclusive to running, is often broadly referred to as "shin splints"; however, there are a few distinct conditions that you may experience in the lower leg (i.e. shin), each having its own possible causative factors and relieving strategies.
 
True shin splints are known as Medial Tibial Stress Syndrome (MTSS).  The location of pain is the inner (medial) border of your shin (tibia), typically over a broad area, and develops over time.  It is common in newbie runners or when running volume is increased too rapidly without ample time for your body to adapt.  Hard running surfaces and hill running are also potential aggravating factors.  Pain is initially felt after a run or the next morning as the tissues start healing.  Calf muscles which attach along this edge can become irritated.  The bone itself is subjected to more stress as well and can be a contributing source of discomfort.  Over-pronating or having a high arch with a more rigid foot often results in suboptimal loading mechanics which may also play a role.  As such, it is important to wear shoes with the appropriate amount of motion control for your feet and orthotics may be a consideration for some.  Relative rest with cross training (i.e. doing a different activity that doesn't cause pain), treatment to manage pain and inflammation, and then a gradual resumption of running is usually successful in managing this complaint.
 
If the pain does persist despite treatment and appropriate rest, or it becomes localized to a small area along the bone, a tibial stress fracture diagnosis should be considered.  Also, unlike MTSS, symptoms may be better in the morning after a period of rest.  X-rays often miss a stress fracture so a bone scan may be necessary to find the "hot spot" where the fracture is located.  A prolonged period of rest, which may still involve cross training, is necessary for the fracture to heal.
 
Another area in the lower leg where runners may experience "shin splints" is the upper, outer portion of the front of the shin.  Pain here typically comes on during a run and forces you to stop running, but then resolves quickly over time.  This scenario is descriptive of Chronic Exertional Compartment Syndrome (CECS).  Muscles in this part of the leg are surrounded by a dense, inelastic tissue called fascia.  With exercise, the muscles become engorged with blood and expand in a confined space determined by the fascia.  If your body cannot clear the extra fluid quickly enough the pressure in the tissues increases and results in pain.  This is not to be confused  with the medical emergency of Acute Compartment Syndrome where pressures increase due to bleeding as a result of a trauma and are not relieved with rest.  Gradually progressing your running volume and/or adopting a more forefoot running style, which uses the muscles in this area of the leg less, may be effective in managing this condition.
 
So, as you head out in the nice weather to be active, wear good shoes and progress your activity level gradually.  After all, as with most healthy habits, the desired results are achieved only if the change is regular and sustainable.
This article is for general information purposes only and is not to be taken as professional medical advice.