If patients present to a physiotherapy clinic with pain or other unpleasant symptoms anywhere between the knee and the ankle, their self-diagnosis is more often than not, “shin splints”. We have all heard the term but how many of us actually understand what it is or in fact, if it’s what they actually have? This post discusses the differential diagnosis of shin pain and the best way to go about doing something about it.
Leg pain (pain between the knee and ankle) in the general population is common and has many different aetiologies. The most common causes include muscle or tendon injury, medial tibial stress syndrome (shin splints), stress fractures, and compartment syndrome. Less common causes of leg pain include lumbosacral radiculopathy, lumbosacral spinal stenosis, focal nerve entrapment, vascular claudication from atherosclerosis, popliteal artery entrapment syndrome, and venous insufficiency.
Sometimes, symptoms associated with these conditions often overlap, making a definitive diagnosis difficult which is why comprehensive subjective (you tell us) and objective (we assess you) examinations are imperative to confirm a diagnosis. Confirmation of the diagnosis requires performing the appropriate diagnostic studies, including radiographs, bone scans, magnetic resonance imaging, magnetic resonance angiography, compartmental pressure measurements, and arteriograms if necessary, to parallel physiotherapy.
Read on to learn about how to differentiate and optimally treat shin pain.
Medial Tibial Stress Syndrome (Shin Splints)
This is the inflammation occurring where a tendon or muscle attaches to bone, in this case, the tibia or “shin bone”. Tendons and muscles attach to the bone via a layer of connective tissue called the periosteum. When muscles contract, they pull on the periosteum and, with overuse, poor biomechanics or excess muscle tightness, this pulling can damage the periosteum. Inflammation and hence, pain result as the body tries to repair itself.
Medial Tibial Stress Syndrome is often felt as pain on the medial or inner border of the tibia as is usually painful as you begin exercising however, as you warm up the pain may lessen. As the effects of inflammation are delayed, the pain usually returns post activity. The area may be tender to touch and there may be swelling around the tibia.
It is extremely important that do you not ignore the problem as, even though the pain may ease temporarily, the constant stress on the tibia can lead to further problems such as stress fractures which will be discussed below.
Stress fractures are incomplete fractures or cracks within the tibia/fibula. When the tibia/fibula are loaded or stressed in any weight bearing exercises, the bones respond by increasing production and turnover. This involves the removal of weakened, damaged bone and the laying down of new bone. If new bone formation cannot keep up with bone removal, areas of weakness can occur. There are many contributing factors, similar to those of medial tibial stress syndrome. Changes in training, training surfaces, footwear, commencing a new activity, biomechanical abnormalities, muscle imbalance or fatigue or menstrual disturbances can contribute.
Stress fracture pain usually increases over a period of weeks and the pain is generally localised and made worse with exercise. Initially it may have only been present after activity, however with continued loading and stress, the pain may start to be present during exercise. The pain may become too painful and be present at night.
Compartment Syndrome (Anterior and Posterior)
Compartment syndrome refers to exercise induced leg pain resulting from muscles swelling and hence an increase in pressure in the deep anterior (front) or posterior (back) part of the lower leg.
The muscles in the leg are divided into separate compartments by tight connective tissue. When you exercise, blood flow to the “compartment” increases as the muscles swell with use. When there is not enough room within the compartment for this increased muscle volume, compartmental pressure increases. Pain usually occurs because blood flow to the muscles and nerves in each compartment is compromised. Factors that may contribute to compartment syndrome include an increase in size and volume of the muscles, strenuous exercise or tightening of the connective tissue.
Posterior compartment syndrome is usually pain along the inside edge of the tibia whereas anterior compartment syndrome, which is more common, is usually felt on the outside of the front edge of the tibia (see picture above). Both usually worsen with exercise and do not settle until you stop, as muscle volume and pressure are able to return to normal. In some instances, lower leg weakness and numbness due to nerve compression within the compartment can be experienced.
An accurate assessment and diagnosis is required before a treatment protocol can be put in place. Like with any treatment protocol, treatment is directed towards the underlying cause. If medial tibial stress syndrome is suspected, physiotherapy treatment may involve activity modification, soft tissue treatment such as massage and stretching, acupuncture, taping techniques and the correction of abnormal biomechanics.
If a stress fracture is suspected, the assistance of a sports medicine doctor is imperative. If the diagnosis is confirmed via a bone scan or MRI (and x-ray will not signify the damage), this will then usually involve a period of rest and the use of crutches, pain relief and icing. Activity modification and correcting abnormal biomechanics is then employed. In the meantime, low impact swimming, deep water running and cycling can assist in maintaining an aerobic base without delaying healing.
If compartment syndrome is suspected, whether it be an acute or chronic presentation, compartment pressure testing may be required, measuring the pressure within the muscle compartment before and after exercising. The diagnosis is positive if the pressure is high and takes a long time to settle after exercise. Usually, treatment is then similar to that of medial tibial stress syndrome, however, in some cases, surgery is required to allow the muscle to “expand”, decreasing pressure within the compartment.
Correction of a patient’s lower limb biomechanics is a must for shin conditions. Please take the time to read this blog about the biomechanics of runner’s knee and you will understand how it correlates to the management of shin pain.
Now you understand why your physiotherapist may give you bum strengthening exercises and discuss orthotics to address your shin pain!
It is extremely important not to “push through” shin pain as it can lead to the above mentioned diagnoses. For any situation it is important to correct abnormal biomechanics and modify activity, both which can be discussed with your physiotherapist.
Lauren is the Principal Physiotherapist and co-owner of South Perth Physiotherapy. Lauren has treated many “shins” over the years and enjoys working with all walks of life, from those who have endured a long beach walk and developed aching shins to elite athletes who are required to follow a rehabilitation protocol after a connective tissue release in order to get back on that pitch.
Brukner P, Khan KM, Clinical Sports Medicine 4th Edition. 2012.
World J Orthop. 2015 Sep 18;6(8):577-89. doi: 10.5312/wjo.v6.i8.577. eCollection 2015.Aetiology and mechanisms of injury in medial tibial stress syndrome: Current and future developments. Franklyn M1, Oakes B1.
Stress Fractures: Diagnosis, Treatment, and Prevention. Deepak S. Patel, MD, Matt Roth, MD, Neha Kapil, MD, Am Fam Physician. 2011 Jan 1;83(1):39-46.