Non-specific term used to describe pain in the front part of your lower leg. Shin splints are really a symptom rather than a specific diagnosis because they are probably caused by a number of different problems. It generally encompasses three conditions that can affect the lower leg – Medial Tibial Stress Syndrome (MTSS), Tibialis Anterior compartment syndrome or stress fracture of tibia.
Medial Tibial Stress Syndrome (MTSS)
MTSS is an inflammation of the muscles, tendons, and bone tissue typically occurring along the inner border of the lower tibia, where muscles attach to the bone. It is thought that the muscle or fascia exerts excessive traction or tensile forces on the medial border of the tibia. Researchers have implicated the posterior tibial (PT), flexor digitorum longus (FDL) and soleus muscles as being possible sources for a traction injury to the medial tibia that could cause MTSS. The other theory for the cause of MTSS and the one that has recently been gaining increasing favor is that the bone injury is due to excessive bending of the tibia during running and jumping activities.
MTSS often occur after sudden changes in physical activity. These can be changes in frequency, such as increasing the number of days you exercise each week. Changes in duration and intensity, such as running longer distances or on hills, can also cause shin splint
The pain from MTSS generally only occurs during the activity with the pain diminishing rapidly within five minutes of activity stops. Bone scan and MRI are best imaging for diagnosis.
Anterior Compartment Syndrome
Your lower leg is divided up into four or five compartments with different muscles, nerves, blood vessels and tendons running through these compartments. The compartment is surrounded by fascia, which helps to improve the efficiency of contraction and divide the muscle from surrounding tissue. Sometimes the pressure within one or more of these compartments increases to the point that the muscle, blood vessel or nerves are compressed. This can cause pain and loss of function. It is often found in runners as a result of the high repetitive loads that occur with running.
Tightness, burning, pressure, cramping and/or pain in the lower leg every time you exercise. The pain commonly occurs in both legs. The onset of these symptoms occurs at predictable intervals (for instance, 4 minutes into every run). They may also experience sudden fatigue on the top of your foot or ankle, numbness in the webbing near your big toe, or even drop foot (this is quite uncommon). Sometimes there may be lumps or bumps in the tissue due to small hernias. Patients usually do not experience pain on firmly touching the affected area.
It is normally diagnosed with subjective and physical examination from your podiatrist. However compartment pressures can be measured by inserting a needle inserted into the compartment attached to a pressure monitor. If the difference between the resting pressure and the pressure measured immediately after exercise is too high then this is a positive test for exertional compartment syndrome.
Treatment
-
Ice – Use cold packs for 20 minutes at a time, several times a day. Do not apply ice directly to the skin.
-
Rest/modification of activities – Lower impact types of aerobic activity can be substituted during your recovery, such as swimming, using a stationary bike, or an elliptical trainer.
-
Non-steroidal anti-inflammatory medicines. Drugs like ibuprofen, aspirin, and naproxen reduce pain and swelling.
-
Massage – DCTM is particularly good for compartment syndrome
-
Strapping – Low dye strapping to reduce strain on muscle, ligaments and tendons. Rock taping on muscles and lower leg
-
Physical therapies – TENs. Ultrasound, shockwave, acupuncture etc
-
Exercises – Strengthening Tibialis Posterior muscle for MTSS or Tibialis anterior muscle strengthening
-
Stretching – Stretching tibialis anterior can give some temporary relief for compartment syndrome
-
Footwear – Firm heel counter and Firm midsole
-
Orthotics – improve biomechanical issues to reduce movement of muscles, tendons and bone tissue.
Keep in mind that when you return to exercise, it must be at a lower level of intensity. You should not be exercising as often as you did before, or for the same length of time. Be sure to warm up and stretch thoroughly before you exercise. Increase training slowly. If you start to feel the same pain, stop exercising immediately. Use a cold pack and rest for a day or two. Return to training again at a lower level of intensity. Increase training even more slowly than before.
If the pain persists during walking activities, the clinician should have a high index of suspicion for medial tibial stress fracture (MTSF). These may occur in the same areas of the medial tibial border as does MTSS
Tibial Stress Fracture
A stress fracture is a crack that does not go completely through the bone. During weight-bearing activity (such as running), compressive forces are placed through the tibia. In addition, several muscles attach to the tibia, so that when they contract, a pulling force is exerted on the bone. When these forces are excessive, or too repetitive, and beyond what the bone can withstand, bony damage can gradually occur. This initially results in a bony stress reaction, however, with continued damage may progress to a tibial stress fracture.
Patients with this condition typically experience a gradual onset of localized pain along the shin bone. The pain is often sharp or acute in nature and typically increases with impact activity and decreases with rest. Occasionally pain may be felt with rest or even at night. In severe cases, walking may be enough to aggravate symptoms. Patients with this condition typically experience tenderness on firmly touching the front aspect of the shin/bone.
Because the fracture is not completely through the bone, often it does not show up on traditional X-rays, and therefore a bone scan is a better way to detect the problem. The bone scan will show the approximate site of a fracture; however, it is not highly specific as to its exact location and extent. Therefore, a follow-up MRI or CT scan sometimes is done.
Unfortunately this is one of few injuries that require rest for it to heal. This could take 6-8 weeks to happen. If it is not rested the fracture could continue to a full thickness fracture. It should be 100% pain free before you return to activity. Scans should also be used to confirm that it is healed.
