A visual example of the consequences of a leg length discrepancy.

This patient has an anatomical (femoral) discrepancy between three and 5 mm. She has occasional lower back discomfort and also describes being very “aware” of her second and third metatarsals on the left foot during running.

You can clearly see the difference in where patterns on her flip-flops. Note how much more in varus wear on the left side compared to the right. This is most likely in compensation for an increased supination moment on that side. She is constantly trying to lengthen her left side by anteriorly rotated pelvis on that side and supinating her foot  and trying to “short” the right side by rotating the pelvis posteriorly and pronating the foot.

With the pelvic rotation present described above (which is what we found in the exam) you can see how she has intermittent low back pain. Combine this with the fact that she runs a daycare and is extremely right-handed and you can see part of the problem.

Leg length discrepancies become clinically important when they resulting in a compensation pattern that no longer works for the patient. Be on the lookout for differences and wear patterns from side to side.