SHIN SPLINTS: Not Such a Simple Diagnosis
‘Shin splints’ is one of the most common reasons for exercise-induced leg pain. One of my favourites, too!
The incidence is as high as 6-16% of all running injuries. With this gorgeous weather at the moment and with the prospect of the 2013 marathon season closing in, further awareness of the possible causes of your leg pain is essential in effective management and prevention.
Shin splints, as it is most commonly referred to, refers to pain on the inside of the shin bone. It does not imply a specific diagnosis, but rather the presence of pain over the shin. Specific anatomical and pathological differences exist that lead to differential, and more specific, diagnoses.
The pain felt can be due to problems of the muscles, the bone, or the attachment of the muscles to the bone. Therefore based on your specific diagnosis, management and treatment will vary.
For optimal management and recovery, assessment by a physio should be undertaken to ensure an accurate and specific diagnosis. The three main pathologies that can cause shin pain are:
1) Medial tibial stress syndrome:
Medial tibial stress syndrome occurs when overuse causes irritation and microtrauma to the soleus (our deep calf muscle) at the attachment to the shin bone. Repetitive stress can also cause irritation to the tibialis posterior muscle, and inflammation of the periosteum (the connective tissue that covers the bone.) This is what most people are talking about when they refer to ‘shin splints’ as their diagnosis. Patients complain of a diffuse pain along the inside of the shin, which usually decreases with warming up so they are able to complete the rest of their training. However pain returns after finishing training and is worse the next morning.
2) Medial tibial stress fracture:
This is most common in athletes involved in running, jumping and impact sports. The incidence increases if play is on a rigid, unforgiving surface. It results as a continuum from increased bone strain, to stress reaction, to finally a stress fracture. Pain has often developed gradually, and usually correlates with an increase in training. Pain worsens throughout a training session and often is present at rest or a night. There is often a focal pain when palpating the shin bone, and a bone scan or MRI can accurately confirm the fracture (an X-ray will often not show it in the early phase.)
3) Exertional compartment syndromes:
The lower leg has a number of muscle compartments, each enveloped by a thick fascia which has limited flexibility. Increased blood flow to the muscle with exercise causes the muscle to increase in size- hence increasing the pressure within compartments. This can lead to decreased blood flow and tissue perfusion, which in turn causes pain. The athlete complains of an increasing achy pain and tight sensation with exercise, but these symptoms usually have disappeared within a few minutes of rest, and are absent at night. Treatment is initially conservative; with deep massage therapy, dry needling, lowering the heel in a shoe, and reducing exercise load. However if this is unsuccessful, surgical release may be necessary to release the fascia surrounding the compartment, with 80-90% of people being able to return to their previous level of sport.
The foundation of treatment starts with an accurate diagnosis.
As evidence to date has still not specifically determined a cause, prevention is difficult; however there have been proposed risk factors. Predisposition factors include abnormal biomechanics, (for example pronated feet) ankle instability, weak soleus or tibialis posterior muscles, stiff ankle joints, inadequate shoes, body mass index, inadequate calcium intake or recent growth spurts. Symptomatic relief, (rest, ice) identification of risk factors and treating the underlying pathology are essential for effective management. Regular calf stretches and releases are integral. Increasing the strength and endurance of the soleus/tibialis posterior, controlling over-pronation, and promoting adequate shock absorption via insoles and new shoes is successful treatment. Committing at least one day per week to a pool/cycling/cross-fit session is shown as effective management of medial tibial stress syndrome and also at decreasing load to reduce the risk of medial tibial stress fractures.
Continuing to push through shin pain can have dire effects on not only your sporting performance and event participation, but also cause further damage in the long term. See your physio for an accurate diagnosis and management to maximise your ability this upcoming running season
in other words…. take care of yourself and get a little TLC from your physio!
All the best,
The Office Athlete