Shin Splints: What are they? Why do they happen? What can you do about them?
Shin splints, technically known as medial tibial stress syndrome (MTSS) affects 5-35% of runners. It involves pain on the inside of the lower leg that occurs with running and typically develops gradually.
Though some aspects of the pathology remain unclear, we do know it involves the interaction of the tibialis posterior, flexor digitorum longus muscles; possibly the soleus muscle; the crural fascia (a connective tissue in the lower leg); and their attachment onto the tibia bone. In prolonged, chronic cases we see a stress reaction in the bone where there is an inflammatory response in the outer layer called the periosteum.
How do I know if I have MTSS?
MTSS has some specific and consistent characteristics that differentiate it from other lower leg injuries:
- Exercise induced pain in the lower 2/3 of the inside (medial side) of the tibia
- Pain during and shortly after physical activity that decreases with rest
- Pain to the touch on the medial side of the tibia that is diffuse, meaning the area of tenderness occurs in an area >5cm
- Absence of cramping, burning, and/or numbness/pins and needles in the foot
- Absence of significant visible swelling along the medial border of the tibia
The location of the pain (medial tibia), size of the pain area (>5cm), and provocation and reduction of pain (increases with activity and decreases with rest) are the characteristics that differentiate MTSS from other conditions such as tibial stress fracture, chronic exertional compartment syndrome, or soleus strain.
Risk Factors for Development of MTSS include:
- Previous history of MTSS
- Fewer years running experience
- Recent rapid or significant increase in running volume
- Higher body weight or BMI
- Decreased hip abduction strength
- Increased ankle plantar flexion range of motion, decreased ankle plantar flexion strength
- Stiffness or tightness of tibialis posterior and flexor digitorum longus muscles
- Decreased ankle dorsiflexion range of motion
- Increased pronation in the foot (at the rear foot and mid-foot)
Management:
Management for MTSS is multifaceted. Here is where you can start:
- Modify running volume and intensity
- If you have ramped up your running too quickly, you will have to back off to allow things to settle back down
- A graded return to running program with the addition of stretching and strengthening of the calves (more on that later) has been shown to be the best and fastest route back to sustainable running
- Refer to a physical therapist or run coach for guidance on how to progress your running volume and intensity. They will be your best resource for knowing when to push through discomfort and when to back off.
- Have your gait assessed
- Limitations in trunk, pelvis, and hip control can lead to increased loads on the tissue in the lower leg.
- Decreased flexion in the knee when weight bearing may also be a contributing factor
- Cadence or step rate can also be evaluated and altered to change the load on the tissues in the leg to reduce MTSS
- Getting your gait analyzed by a physical therapist or provider that has experience in this area will be the fastest way to begin making the appropriate changes to your running technique to return to pain free running
- Improve your mobility and strength
- Ankle dorsiflexion (think toes towards your shin) stiffness is known to be a contributing factor. This is likely due to the tightness of the tibialis posterior and flexor digitorum longus muscles that contribute to MTSS. Increasing the mobility and flexibility of these muscles should reduce the stress on the tibia that is causing the pain.
- Ankle plantarflexion (think pushing a gas pedal) weakness is also a risk factor. Increasing the strength of these muscles will help decrease the symptoms and should help reduce the likelihood that they will return in the future.
- Hip weakness is important as well as it will affect the ability to stabilize the trunk and pelvis as seen in the gait assessment. Making the hips stronger, particularly into abduction, will ensure that the leg remains in the best possible position from the pelvis to the foot to prevent overuse of the muscles in the lower leg as the try to compensate for the lack of stability above
- A physical therapist with expertise in creating strength programs for runners can provide advice on the specific exercises to do and the appropriate amount of each exercise to optimize the outcome.
Medial tibial stress syndrome is a condition that many runners have experienced at some time over their running careers. The good news is, with appropriate management, it does not have to be a chronic or recurrent condition. If you find yourself with the symptoms mentioned above, get an appointment with a physical therapist who works with runners. They can look at the risk factors, your training and running experience, your gait, and your flexibility and strength to create a program that will quickly and sustainably get you back on your feet!
See you on the roads and trails!
