(Part 1: Medial tibial stress syndrome & compartment syndromes) 

Shin splints are one of the most common conditions that active exercisers and sports people experience. The term “shin splints” is given to any pain that is felt over lower part of the leg between the knee and the ankle, and is brought on by exercise or physical activity. However, shin splints are not just one single condition and as the treatment for each condition differs, it is important to try and understand them. In the next few SPORTZDOC articles, I will focus on the main conditions that give rise to shin splints: medial tibial stress syndrome, compartment syndromes, and stress fractures. Hopefully this will help you improve the way you manage your shin splints.

MEDIAL TIBIAL STRESS SYNDROME (MTSS)

What you feel:

• Medial tibial stress syndrome starts as pain over the front of the shin on the inner side of the lower leg especially in sports that require running and jumping, or take place on hard surfaces (eg. running, netball, basketball, soccer, exercise walking). Most frequently, the pain is felt in the lower half the shin bone (the tibia).
• The shin pain is felt when you start exercising (eg. a run, or step exercise) but gets a little less as you warm up. Over time, the pain persists for longer periods during exercise until it may be present throughout the duration of the exercise. If left untreated, the shin pain may then be present during non-exercise activities such as walking or descending stairs.
• As the condition progresses, there may be soreness or pain when you press the shin bone and the muscles next to it on the inner part of the bone.

What causes it:

• Medial tibial stress syndrome arises from repeated exercise that literally overuses the lower leg. MTSS is thus an overuse injury that results in an injury response called inflammation. This affects the lining that covers the tibia (called the periosteum) as well as the tendon of the muscles that are attached to persiosteum. Repeated exercise does not allow this inflammation to resolve, leading to more injury (called a tenoperiostitis, in some books).

What makes the condition worse?

• MTSS often occurs when you suddenly increase your physical activity, especially that involving running or jumping. This increase could be in your exercise frequency (number of times each week), the intensity (eg. faster runs), exercise duration (eg. longer runs, extended exercise sessions), and more activity on uneven, hard ground.
• In addition, sports shoes which are old or wearing out, and insufficient warming up also increases the likelihood of developing this condition.
• If you have flat feet or arches which pronate (lowered or collapsing arches), the risk of developing medial tibial stress syndrome increases, particularly when you are not using the most appropriate sports shoes to support your arches.

How is it treated?

• Treating the medial tibial stress syndrome is based on managing the inflammation at the injury site, and then taking steps to prevent recurrence as you return to your favorite activity. It is helpful to be reviewed by a sports medicine professional so that the whole injury management plan can be integrated carefully.
• The immediate treatment involves reducing the amount of physical exercise as this aggravates the injury. You may be prescribed some anti-inflammatory medication as well as receive some physiotherapy treatment. Certain stretching exercises will also be taught to you.

What preventive steps can I take for this form of shin splints?

• The prevention of medial tibial stress involves careful management of your overall exercise and training volume (ie. the frequency, intensity, and duration) to avoid sudden increases that lead to injury. A step-wise and progressive build-up is called for especially if the surface that you exercise on is hard or uneven. This is especially so at the start of training for a new sports season, or in building up to a running event.
• Attention should also be given to achieving and maintaining good flexibility and strength of the muscles and joints of the leg. Your sports shoes deserve to be given special attention too: they should be cushioned (to reduce impact forces being sent up your leg), and if your pronate or have flat feet, they should support the arches of your feet well.
• You may need to consider using cushioned arch insoles as well in order to give the right level of support for your feet and to control the arch collapse. As you return to exercise from injury, it is helpful to use a softer surface to run on (eg. a running track or treadmill).

COMPARTMENT SYNDROMES

What you feel:

• The muscles, tendons, blood vessels and nerves in the lower leg are held in separate compartments. These are given different names, and the compartments which most commonly affect runners are called the anterior (meaning in the front) and the deep posterior compartments.
• Both types of compartment syndromes feature pain the lower leg (shin splints!!) which occurs as you exercise. With increasing exercise, the pain gets worse and may be accompanied by a feeling of tightness in the compartment that is affected; with rest, the pain resolves. In addition, there may also be feelings of numbness or tingling in the foot, and later, a feeling of weakness of the muscles in the feet and lower leg
• Anterior compartment pain and tightness is felt over the front of the shin on the outer part of the lower leg. Nerve compression in this compartment may give rise to numbness or decreased feeling the web space between the first and second toes.
• Deep posterior compartment pain is felt in the area of the calf or along the inner part of the shin, in a similar location to medial tibial stress syndrome. Weakness or pins and needles may be felt in the toes or feet.

What causes it:

• Compartment syndromes are the result of swelling of the leg muscles in their respective compartments. If the compartments are very tight or have been made tighter by repeated inflammation (causing scar tissue bands to form), the normal muscle swelling is compressed and pain results. This pain may be partly due to a cutting off of blood supply to the muscles.
• As the compartments of the leg also contain blood vessels and nerves, these structures are also compressed. This gives rise to sensations of numbness, pins and needles, and muscle weakness.

How to treat it:

• It is important to see your sports doctor to have a proper diagnosis made before you start treating the compartment syndrome. The diagnosis may be made after careful examination, and may require the measurement of the pressure within the muscle compartment.
• Treatment begins with reduction in the level of exercise, and involves deep tissue management by a sports physiotherapist. This can be painful, but is aimed at releasing the tightness of the compartments and the coverings of the muscles. Selected stretching exercises are also taught to you as part of the treatment process.
• The compartment syndrome is also managed through the exercise and physical training sessions you take part in. A good warm-up is followed by more progressive increases in exercise frequency, intensity and duration. Shoe and foot arch factors are also addressed as they were with medial tibial stress syndrome.
• In severe cases of compartment syndromes which do not respond to conservative treatment, surgery may be necessary to physically create space for the muscles and structures within the compartments that house them.