Medial Tibial Stress Syndrome (MTTS), colloquially referred to as “Shin Splints,” is a common lower extremity injury to the inner side of the tibia (shin bone). It predominantly affects an athlete engaged in high-impact weight-bearing activities, such as running and jumping.
What causes MTSS?
When dealing with bone injuries it’s important to understand the multitude of factors that influence the breakdown of the tibia. These factors under the right conditions allows a runner to continually adapt and layer down new bone to withstand their training load. When the delicate balance of their contributing factors falls out of equilibrium, the tibia (bone) starts to progressively breakdown under stress resulting in inflammation, swelling and eventually a stress fracture.
Training Load Errors
Sudden Increases: Increasing mileage or intensity without adequate time for adaptation.
Inadequate Recovery: Insufficient rest between runs hinders tissue repair and increases the risk of PFPS.
Running and recovery need to live harmoniously in order to allow the bone adequate time to adapt. The typical issue that runners face is inadequate rest between subsequent runs. As well as understanding how much load (both pace and distance covered) can a runner add on every week. The reality is that there is no perfect number when addressing the percentage of load increase. Some runners are more resilient than others and thus can tolerate sharper increases in running load, whilst others need to be conservative with their programming.
Hormonal Stressors
Hormonal factors, particularly those related to the menstrual cycle, significantly impact the development of medial tibial stress (shin splints) in female runners. Here are the key points:
Amenorrhoea and Low Estrogen Levels: Estrogen is vital for maintaining bone density by promoting bone formation and inhibiting bone resorption. A regular menstrual cycle ensures a steady supply of estrogen, keeping bones strong. Loss or reduction of the menstrual cycle (amenorrhoea) leads to low estrogen levels. This is often due to low energy availability, excessive physical stress, or weight loss, common in intense sports like running.
Diet & Fuelling
Dietary factors, particularly under-fuelling, can significantly impact the development of medial tibial stress (shin splints) in runners. Here are the key points:
Energy Deficiency: Under-fuelling results in inadequate energy availability, meaning the body doesn't get enough calories to meet the demands of training and basic physiological functions. This leads to compromised performance and recovery. Under-fuelling hampers the body's ability to repair and rebuild tissues. This delayed recovery starts a cascade of events that results in your body’s inability to form new bone and maintain strong bones. In female runners, prolonged energy deficiencies can lead to a loss of their menstrual cycle. As mentioned above, this can have a significant impact on estrogen production and bone remodelling.
Running Biomechanics
Over-striding in runners increases the risk of medial tibial stress (shin splints) by amplifying impact forces, reducing shock absorption, and creating higher braking forces. When runners land with their foot too far in front, it leads to heel striking and inefficient shock absorption, concentrating stress on the tibia. This repetitive strain disrupts the balance of load distribution, heightening the risk of injury. Proper running form is essential to minimise these risks.
Signs and Symptoms
Shin Pain: MTTS manifests as exercise-induced shin pain. The discomfort typically resides in the middle and lower third of the tibia.
Tenderness: Palpation of the lower inner shin reveals tenderness.
Provocative Movements: Explosive movements (like hopping or jumping) exacerbate the pain, distinguishing MTTS from other conditions. In severe cases, walking and performing heel raises can be symptomatic.
Energy deficiencies: has there been a lack of dietary intake resulting in fatigue, reduced concentration and the lack/absence of sex drive (both male and female).
Menstrual Cycle: Has there been a loss of reduction (flow and/or frequency) of your menstrual cycle.
Self-Diagnosis Techniques
While consulting a healthcare professional is essential, you can perform some self-diagnosis steps to give some insights whilst to wait to see a Professional:
Location of pain around the middle to lower inner shin.
Pain with performing heel raises. Here we are looking for not only symptom reproduction but also if there is a significant difference between limbs.
Pain with single leg hopping and/or lack of good quality hops (hopping frequency, height and ability to absorb force on landing).
It’s important to understand that medial tibial stress is an injury with progressive changes to the outside (periosteum) and inside (bone marrow). Left untreated or poorly managed it can lead to the stress fracture as seen in the image (Grade 4b). It’s also important to note that pain does not correlate with damage and hence pain as your only guide can be misleading.
Effective Self-Management Strategies
1. Modify Training Load
Modifying training load is beneficial in managing medial tibial stress syndrome (MTSS) as it helps prevent overuse injuries by allowing adequate recovery time and reducing repetitive stress on the tibia. Adjusting training intensity, duration, and frequency can help alleviate symptoms and prevent the progression of the injury. Based on the Fredericson MTSS grading there are differing levels of time off running with progressive rehabilitation required during this time and after the recommencement of running.
Rehabilitation is essential across all grades of MTSS and its implementation needs to be individualised based on the athlete and their symptoms.
Grade 1: Rest can vary from a few days to 2 weeks depending on the severity of symptoms. Return to running needs to be carefully implemented alongside allowing time for rehabilitation to take effect.
Grade 2: Rest period between 2-6 weeks. Runners may require a progressive run/walk programme.
Grade 3: Rest period of 6-10 weeks. A run/walk programme is mandatory.
Grade 4: Rest Period of 12-14 weeks. A run/walk programme is mandatory.
2. Strength and Plyometrics
Strength exercises, particularly those involving axial loading and plyometrics, are crucial in the management of medial tibial stress syndrome (MTSS). Axial loading exercises, such as squats and deadlifts, help strengthen the bones, muscles, and connective tissues of the lower limbs by applying direct, weight-bearing stress. This strengthens the tibia, improves bone density, and enhances the muscles' ability to absorb impact forces. Plyometric exercises, such as jump training, increase muscle power and improve neuromuscular coordination, which helps to better manage the repetitive stresses of running and reduce the risk of overuse injuries like MTSS. It’s important to add in plyometrics at the right time and more importantly with the accurate dosage to allow for positive adaptation to the bone and avoid any flare-ups with overload.
Continual implementation of these strength exercises after a return to full running and training is essential for maintaining the benefits gained during rehabilitation. Ongoing strength training helps prevent the recurrence of MTSS by ensuring the muscles and bones remain strong and resilient to the stresses of running. It also promotes better running mechanics and endurance, which are vital for sustaining performance and preventing future injuries. Maintaining a regular strength training routine is key to long-term injury prevention and overall athletic performance.
3. Biomechanical Tweaks
Increasing Cadence by 5-10% (whilst maintaining the same pace) can significantly reduce over-striding, By shortening the stride (by increasing cadence) and ensuring the foot lands closer to the body's centre of gravity, runners can reduce excessive forces, improve shock absorption, and distribute the load more evenly across the lower limbs.
4. Nutritional Support
Addressing nutrition and dietary intake to correct underfuelling is crucial in managing medial tibial stress syndrome (MTSS) because adequate energy and nutrient supply are essential for bone health, muscle strength, and tissue repair. Addressing how much and what foods to eat needs to be done in collaboration with a nutritionist or dietitian. They will take into consideration factors such as your age, gender, height, weight alongside your training load and other variables, to provide you with the information of how much energy (calories) to consume to optimise your training.
Remember, MTTS doesn’t always play by the rules. Pain severity isn’t always proportional to the injury’s seriousness. Listen to your body, seek professional guidance, and prioritise your rehabilitation.
For expert help and management please feel free to contact my team at The Running Room (www.therunningroom.net)