Clinical Examination of Leg Length Discrepancy

Abstract

Leg length discrepancy is the inequality between the left and right limbs from the femur to the tibia. There are mainly two kinds of limb length differences, apparent/functional and true/anatomic. Apparent discrepancy is that which ‘appears’ or ‘seems to be true’.  Structurally, there is no difference in bone lengths. True/anatomic leg length discrepancy results from an anatomic or structural change in the lower leg. The leg length discrepancy can be measured in the non-weight-bearing position (supine lying) using the Direct method and weight-bearing position (standing) using the indirect method. LLD significantly influences several pathological and physiological conditions. It has a significant effect on pelvic and lower limb biomechanics. Pelvic obliquity in the frontal plane may lead to functional scoliosis, posture deformation, gait asymmetry and low back pain. Thus it is important to know the various methods to measure LLD.