SPORTS MEDICINE ADVISOR
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Shin Splints
by Neal Sand, MS, ATC, C.S.C.S.
The term "shin splints" is an inadequate and misleading term used to describe a dull aching pain that is experienced in the shins, most commonly along the anterior crest of the tibia and fibula during running type activities. Included in the term "shin splints" is anterior tibialis tendonitis, medial tibial stress syndrome, stress fractures, and compartment syndrome.
Shin splints are the result of overuse. Some general preventative measures an athlete can take in an attempt to prevent shin-splints are to increase training mileage gradually, as a rule of thumb training mileage should not increase by more than 5% weekly. Running shoes lose 2/3's of their shock absorbency at 100 miles, and are down to about 55% at500 miles. Typically, an athlete needs a new pair of shoes every six months. A lack of flexibility resulting in a foot that can not dorsiflex (bring foot towards the shin) more than 10 degrees past perpendicular can contribute to the cause of shin splints.
Before any treatments can be started, a specific diagnosis should be made. Differential diagnosis would include:
Anterior Tibialis Tendonitis - causes pain along the anterior lateral tibia (front of the shin). If the athlete tries to point the foot up towards the shin (dorsi-flexion) the muscle will be stressed and cause discomfort. When running, the anterior tibial muscle prevents the foot from slapping the ground after the heel strikes the ground. It is common with runners, running up hills and with soccer players who have suddenly increased kicking with their instep. Athletes with a tight achilles tendon, weakness of the anterior tibialis muscle, or little foot protection on hard surfaces seem to be more susceptible.
Treatment would consist of decreasing or resting from the offending activity, stretching the achilles tendon and strengthening exercises from the anterior tibial muscle. When training resumes, hills and hard surfaces should be avoided until pain is completely gone.
Medial Tibial Stress Syndrome -otherwise known as posterior shin splints. Typically, when someone says they have shin splints, this is the injury they are usually referring to. The pain is on the inside of the shin where the tendon attaches to the periostium (lining of the bone). Typically, the pain seems worse as exercise is begun then it subsides as exercise continues. The exact muscle involved is controversial. In the past, it was believed to be the posterior tibialis. It is now believed to be the soleus muscle.
Athletes that over-pronate and have tight achilles tendons are susceptible to this injury. Pronation is when the feet slant inward while standing. Runners that run in only one direction on roads, may put one shin at risk because of the slant of roads that allows water to run off them.
Treatment for this type of shin splint is rest, ice, stretching the achilles tendon, and strengthening exercises for the arch. Chronic conditions that come back year after year may need orthotics to correct foot over-pronation. As a rule of thumb an athlete should rest until he/she can press on the shin and not cause pain. This can take anywhere from one week to six weeks. When the running program is started again, it should be with gradual increases in mileage, not where the athlete left off prior to the injury.
Tibial Stress Fractures - can result with a shin splint condition where the athlete continues to train through the pain. The pain is extremely point tender over a small area, usually on the proximal (top) or distal (bottom) of the tibia (shin bone). The pain usually starts with exercise and becomes more intense with exercise. Many times the fracture is not seen on the initial x-rays, and not until three weeks later is new bone seen indicating there was a fracture This is why it is often misdiagnosed as atypical shin splint (tendonitis). Stress fractures happen most often with an inactive person who begins a running program and over does it.
Treatment is rest with no running for about four to eight weeks. During that time, the athlete is permitted to swim and cycle.
Compartment Syndrome - Can be a potentially serious problem. This syndrome occurs when the leg muscles become swollen from exercise causing blood supply to be restricted. The foot and lower leg may become numb. A full blown compartment syndrome produces severe pain. There will be no improvement with rest or ice, the shin gets "woody hard". This is a surgical emergency requiring immediate release.
A chronic compartment syndrome is more common in runners. Sometimes the runner can tell you at what distance in the run the pain will start. Pain will increase during activity with rapid improvement when running stops. When examined, there is often no tenderness. If suspected, compartment pressures can be measured before and after exercise showing increased pressure of the specific compartment. Treatment consists of resting from the off ending activity, icing, stretching, and physical therapy lasting six to twelve weeks. If conservative treatment fails, then a surgical release may be needed.
In conclusion, the term "shin-splints" is a vague term that can mean a number of different ailments of lower leg pain from overuse. Prevention is the best cure. Recognizing signs and symptoms, gradually increasing mileage, proper foot wear, and a flexibility program of the achilles tendon can help to prevent shin splints to some degree. But when an athlete has shin splints, the type should be determined before a rehab program can begin.
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