The first thing that should be considered is that there are two types of short-leg syndrome (SLS):
Anatomical Short Leg. The measurement from the bony protuberance (the greater trochanter) of the hip joint to the lateral ankle measures shorter on one side than the other. This is seen in approximately three percent of all short-leg syndromes.
Functional Short Leg. The measurement from the same two points is equal on both sides, but there is still an apparent short leg. With this type an apparent short leg. With this type, there is usually a rotation or displacement of the pelvis on one or both sides. This causes abnormal stress on all muscles, nerves and joints that are involved. The longer a person has this type of SLS, the greater the chance for a secondary compensatory problem somewhere else in the body, usually in the upper back, shoulders or neck. Common symptoms here are muscular pains in the involved areas, headaches, numbness and/or tingling in the arms or hands.
There is an easy way to help determine which type of SLS you may have. It is known as the Deerfield Test. With the person lying face down, check the length by correcting any pronation or supination of the feet so that the heels are parallel and perpendicular to the plane of the legs. This is easier to visualize with shoes on than with bare feet because the shoe has a flat heel as opposed to the foot's rounded heel.
After noticing which leg is short, flex both knees to 90 degrees. If it is anatomical shortness, the difference in leg length will be identical in positions 1 and 2. If it is a functional shortness, the short leg will be either become as long as the other leg or longer when in the flexed position. This is called cross-over. Whichever syndrome one is suffering from, the weight distribution through each leg will be uneven. Because of the increase in poundage and stress out on the body and legs during running, the symptoms will be more pronounced in a runner than a non-runner.
Any symptom that is exaggerated by running, such as low back pain, hip, knee, ankle or foot pain should lead you to suspect SLS. A tendency to pull repeatedly the same muscle even though you have given it sufficient time to heal is a symptom commonly seen.. Also, shin splints and sciatic neuralgia (inflammation of the sciatic nerve that produces pain in the buttocks and down the back of the leg) are very common symptoms.
When it comes to a functional shortness, which is more complex, the first thing to consider is the underlying cause of the short leg. Some common causes are: (1) Arches are not the same in both feet. (correction can be aided with the arch supports or orthotics). (2) An abnormal range of motion, in the joints. Each joint, including ankle, knee, hip, and low back, should be put through a full range of motion to ensure normal equal motion. (3) A weakness of one or more lower extremity muscles, which allows the pelvis to rotate either anteriorly (forward) or posteriorly (backward) in relationship to the other side. (4) Bad habits, such as poor posture, slouching in chairs, crossing legs while sitting, standing with all your weight on one leg, always running on the same side of a beveled roads or insufficient stretching. (5) Poor quality running shoes.