Introduction

Lower leg pain is relatively common in the running athlete. Studies have shown that it is second only to the knee in causing lower leg pain, and makes up around 20% of running injuries.

There are numerous causes of lower leg pain in the younger athlete. The most common of these include tibial periostitis (the old ‘shin splints’), stress fracture and chronic exertional compartment syndromes. In the older athlete peripheral vascular disease and spinal canal stenosis should be considered.

Aetiology

Tibial periostitis is an overuse related inflammation of the attachment of the deep calf (generally considered the soleus) to the medial tibial border. It generally comes about with increased training load on top of intrinsic factors such as poor foot biomechanics (particularly over-pronation), and calf inflexibility.

A stress fracture is a failure of normal bone to cope with abnormal loads. It generally occurs in the tibia at the junction of the upper 2/3 and the lower 1/3. Similar factors may cause a tibial stress fracture that cause tibial periostitis, and there may be a continuum between the 2 conditions. In the older female athlete bone mineral density issues should be considered

Chronic exertional compartment syndrome is a condition where the fascial covering of a muscle group becomes excessively stiff. With activity muscles swell and the fascia will stretch to accommodate this. If the fascia becomes stiff – and this may occur due to ageing, genetics or trauma – then the muscle becomes constricted. The causes the microvascular blood supply to become compromised, causing a claudicant type pain.

Diagnosis

A good  history and examination is essential to make a definitive diagnosis. In tibial periostitis the pain may initially warm up with activity and disappear. There may, however, be prolonged post-activity pain. This is an inflammatory history. In contrast, compartment syndrome is usually painless for the first 5-10 minutes of activity and then the pain slowly worsens. It  may be severe enough to make the athlete stop and subsides quickly with rest. This is a claudicant history. Stress fracture pain is largely insidious and progressive, occurring initially after exercise only, then progressing to pain during activity and even rest and night pain.

Accurate examination will aid diagnosis. In tibial periostitis the patient has widespread, exquisite tenderness along the medial tibial border, maximal in its mid-third. In a stress fracture there will be one area of more focal tenderness, generally at the junction of lower 1/3 and the upper 2/3 of the tibia. Chronic exertional compartment syndrome may show little at rest, although examination post-exercise may show increased tension through the affected compartment and sometimes a palpable muscle hernia.

Investigation will help confirm clinical suspicions. A plain x-ray is appropriate to demonstrate a stress fracture, and exclude other pathology, such as a tumor. A bone scan is a helpful second line investigation for demonstrating tibial periostitis and also stress fractures. Similar information may be achieved with MRI scanning without the same radiation. If a compartment syndrome is suspected the gold standard is a compartment pressure test. This involves placing a needle catheter attached to a pressure gauge into the affected compartment. Pressures are obtained both pre and post exercise to establish the diagnosis.

Treatment

Treatment of tibial periostitis and stress fracture is similar. It includes a period of pain free rest of around 6 weeks with ‘hands on’ physiotherapy to release tight soft tissue structures, a rehabilitation program of stretching and strengthening exercises and a biomechanical assessment, possibly with orthotic prescription. In the case of compartment syndrome, surgery may required to release the affected compartment

Appropriate assessment and advice from a practitioner with experience in this area can greatly shorten the time to diagnosis. Institution of appropriate management plan will help get both elite and recreational athletes quickly back to their preferred sport.

Key Points

• Lower leg pain is common in the running athlete
• Common causes in younger athletes include tibial periostitis, stress fracture and compartment syndrome
• In older athletes consider vascular and spinal causes
• Compartment syndrome presents with a ‘claudicant’ history and ‘crescendo’ pain
• Treatment of tibial periostitis and stress fracture requires rest, biomechanical assessment and correction
• Definitive treatment of compartment syndrome usually involves surgery