Shin Splints

By Glenn Lindsay

Introduction

Most medical experts agree that the term ‘Shin Splints’ is probably inappropriate. It is inappropriate because the term can often be describing differing clinical problems involving the lower leg, such as an inflammatory reaction of muscle and tendon or a bone stress response. A diagnosis of ‘shin splints’ may, for example, actually be describing a stress fracture, compartment syndrome or tibial periostitis. The involved anatomy can indeed vary and thus opinions differ on what a more appropriate generic term may be. Some prefer the term ‘medial tibial stress syndrome’. However, for the purposes of this article, ‘shin splints’ are usually associated with pain along the tibia (or shin bone) of the lower leg. This pain is usually located postero-medially (ie toward the back and inside of the lower shin bone), or antero-laterally (ie toward the frontal and outer part of the lower shin) depending on the muscles involved.

What are Shin Splints?

What many experts do agree upon is that ‘shin splints’ are often most likely a stress reaction involving the periosteal (ie outer layer) bone of the distal (or lower) tibia. This stress reaction takes the form of an inflammation of the involved area in response to overloading. The overload can take numerous forms eg excessive mileage (particularly on hard training surfaces), excessive ankle pronation or tight calf muscles (in particular the soleus muscle) causing excessive tractional (pulling) forces where the muscles meet the bone. Hence the term ‘Traction Periostitis’. Other muscles sometimes thought to be implicated in shin splints are Tibialis Posterior, Flexor Digitorum Longus or Flexor Hallicus Longus, all with attachment along the inner aspect of the tibia. Shin Splints can be thought of as an early stress fracture. ie If not treated or rested and you continue to run with pain, this may result in an actual stress fracture.

Diagnosis

Whilst the stress reaction is involving bone, X-rays are in fact poor in regards to indicating this periosteal reaction. Acute shin splints usually show patterns of periosteal changes and bone marrow oedema (ie swelling). Magnetic Resonance Imaging (MRI) is often a good indicator of bone marrow oedema, which in turn may relate to this bone stress response. However, according to some experts, those with chronic shin splints can have a normal MRI. Thus, a bone scan tends to be the most reliable diagnostic indicator, with a ‘Triple Phase Bone Scan’ probably being most sensitive. This type of scan is useful in ruling out an actual stress fracture, and the different phases of the scan can help to detect how acute the condition is.

Clinically however, the differentiation between shin splints and an actual stress fracture is not always clear. Stress fractures do, however, tend to produce a greater localisation of pain (eg. an area less than 5cm), with tenderness increased markedly by percussion (ie tapping).

The pain of shin splints is usually worsened with activity, and eased with rest. Running is the most common causal activity, particularly on hard surfaces or in footwear with worn or inadequate cushioning qualities. Shin splints are also seen in jumping activities, for example gymnastics.

Treatment

Precise treatment obviously depends on the actual diagnosis, but basically speaking the most important thing to do is ‘rest’. This does not mean stay in bed, but to avoid the impact activity causing the problem. Eg Stop running completely and continue other forms of non-impact training which do not aggravate your condition such as swimming or cycling. If the condition is mild and has only just begun, you may get away with immediately purchasing more appropriate running shoes, running in water or simply cutting back on mileage. However, if pain persists then you would be wiser to avoid running altogether and to seek professional opinion. You will definitely not achieve a PB whilst carrying a stress fracture!

In the acute stages, ice is a particularly effective home treatment tool (Eg 15 minutes, 3 times a day). Your doctor may also prescribe anti-inflammatory medications such as ibuprofen. An Air Cast Splint or some methods of taping may allow continued training, as these for example may produce a counter force to muscle or fascia tractional forces on the bone.

In the case of chronic shin splints, the condition may respond to friction massage or ultrasound. Chronic shin splints can be difficult to treat, and in some cases surgery may even be indicated. The biomechanics of your running action can be assessed, often indicating such problems as over-pronation or muscle weakness or imbalance. In the case of excessive pronation, anti-pronation running shoes or corrective orthotics may be prescribed. For muscle imbalances, certain strengthening or stretching exercises may prove useful. Eg Stretching a tight soleus muscle.

Often the basic problem is that the rate of loading is greater than the rate of adaptation. Ie You have simply increased your training intensity or duration too rapidly.

References

  • Donatelli, RA (ed.) The Biomechanics of the Foot and Ankle (1990)
  • Batt, Dr. M. (Sports Physician) Lecture at St. Barts Hospital, London (1999)

Glenn Lindsay is an Australian physiotherapist from Sydney, Glenn completed a diploma in Sports Science at the University of New South Wales before obtaining his degree in physiotherapy at the University of Sydney. A former triathlete and runner, he has undertaken numerous post graduate courses and has lectured physiotherapists and other health professionals both in the U.K. and in Australia. He has vast experience in treating athletes and sports people of all levels, including professional sporting teams and international athletes. Having been in the U.K. for 5 years, he worked both within the NHS and at private and corporate clinics before starting PhysiCo in 1997. He is physio for the Great Britain paralympic and able-bodied swimming team, and the Formula One Jordan Team.