Currently working with a lot of runners, especially high school runners, I am seeing a lot of medial tibial stress syndrome (MTSS) presentations…aka shin splints. Our high school middle distance runners are particularly prone to these injuries. This sort of injury is not uncommon to runners, and can account for up to 30% of all running injuries. It has been a frustrating process of finding what works and what doesn’t from a treatment point of view, and so the idea was to put together an article that can be clinically useful, yet still research based.
To be honest, it is a real struggle treating MTSS. Based on some good systematic reviews of the literature, it has been shown that my struggle is not something new. MTSS can be diagnosed using 3 key symptoms; 1) pain along the posteromedial border of the tibia, 2) diffuse pain, and 3) pain that is activity related. MTSS is an overuse injury, with pain occurring due to traction induced periostitis on the medial tibia because of high muscle forces, or it can be a result of failure of bone remodeling, similar to that of bone stress reactions or stress fractures. A recently published article which received high accolades stated that MTSS can be reliably diagnosed with history and physical examination. This is supported by the fact that MTSS should viewed as a clinical pain condition, as the exact pathology is not always clear.
Studies have shown that there is conflicting evidence for what may actually predispose to getting MTSS. It was recently shown in a systematic review of the literature that of the many intrinsic factors said to be a risk factor, only five had significant risk for MTSS in runners. These are 1) females, 2) high body weight, 3) high navicular drop, 4) previous running injury, and 5) greater hip external rotation with hip flexion. Extrinsic risk factors for developing MTSS should not be disregarded, although there seems to be limited research in this area.
Running kinematics may be one of the biggest role players in development of MTSS. Rearfoot eversion is associated with a lowering of the medial longitudinal arch of the foot (or a navicular drop) and is known to be controlled particularly by eccentric forces. Excessive navicular drop and rearfoot eversion during a gait cycle may place the intrinsic and extrinsic foot muscles under high force loading to eccentrically stabilize the foot and to provide push-off. Higher tensile stress from eccentric muscle action is transferred to the tibial periosteum during high amounts/velocities of rearfoot eversion, with the flexor digitorum, tibialis posterior, or soleus muscles known to be involved. Also, repetition of a prolonged rearfoot eversion action during the running cycle can increase the bending stress on the bone, and if not managed correctly can ultimately lead to bony stress injuries (stress reactions or stress fractures). It has recently been shown that the duration rather than the amount/velocity of rearfoot eversion may be more of a risk factor for developing MTSS. This is because during the push-off phase the foot is to be a rigid lever to transmit forces appropriately; and having the foot still in an everted position (due to a prolonged rearfoot eversion) keeps the bony anatomy in a more flexible configuration, and subsequently a knock-on effect to high loading of medial tibia structures.
So what are the treatment options for MTSS. I think it is safe to say we all have our ‘secrets to success’, but what is actually evidence based treatment for MTSS. You will be surprised to know that NOTHING HAS BEEN SHOWN TO DEFENITIVELY TREAT MTSS. Yip, you read that correctly! That is not to say our treatment options don’t show positive results, but there is no scientifically proven gold standard of care for treating this injury in athletes. This is important when making clinical decisions on behalf of our patients, as there is no evidence to suggest that what we do can explain the improvement of their symptoms or recovery from the injury. Some methods that have been researched but show no conclusive evidence for clinical use are: pulsed EMG, low energy laser, ultrasound, iontophoresis, phonophoresis, periosteal pecking, braces, compression stockings, ice massage, strengthening, and stretching. Low dose shockwave therapy has the most evidence based promise for successfully treating MTSS through a reactivation of the repair process. Methods that are logical and which may be effective in treating MTSS, although currently no studies have been done to verify this, are graded running programs, or the use of plyometric exercises (for bone remodeling). It has been shown that the use of kinesio tape may reduce the rate of medial longitudinal arch loading in athletes with MTSS. This is not useful information for two reasons: firstly, we know that the duration of loading is more of an issue than the rate of loading, and secondly there is no reported reduction in symptoms of MTSS using taping. However, clinically, it may make sense to try and unload the medial tibia structures using this method, especially if it relieves symptoms during initial loading phases (this will be trial and error).
Due to the MTSS best being diagnosed as a clinical pain condition, a patient reported outcome measurement has recently been developed to assist in determination of treatment effects, and may in future be used as a prognosis tool. The MTSS score is a reliable, valid, and responsive four-item scale that addresses the following:
- pain at rest
- pain while performing ADL
- limitations in sporting activities
- pain while performing sporting activities
Based on the evidence based findings represented in the above paragraphs, and from my own personal experience with treating numerous patients with MTSS injury (especially middle distance athletes), I would like to suggest some clinical tips that may be useful:
- Simply ‘releasing’ the calves and medial tibia structures will most likely not resolve the issue.
- Graded loading programs (running, strength, and plyometric) and patient education may be the best option for successful treatment.
- Consult with coaches for commitment to loading programs.
- Do a thorough musculoskeletal assessment to identify and address biomechanical deficits.
- Key biomechanical areas to assess are hip ROM, hip/pelvis/foot static and dynamic stability.
- Don’t use recipes… i.e. one patient may have weak hip abductors, another may not…or one patient may have a high navicular drop, another may not.
- Strapping with rigid taping to reduce medial arch loading rate has proven successful (in my experience) to provide relief of symptoms by unloading the extrinsic foot stabilizing muscles.
- The MTSS score is a useful outcome measure to be used in clinical practice.
- Refer for imaging (xray, CT, MRI, bone scintigraphy, doppler, ultrasound) if stress fractures are suspected.