Summary - One of the problems
facing the clinician is the differentiation between functional and structural
limb-length inequality. This study investigated 20 subjects (mean age, 9.0 ±
3.9 years) with documented limb-length inequalities to determine the magnitude
of discrepancies that result in gait abnormalities. The subjects were asked
to walk on an
8-m walkway at a self-selected free pace. The contact time, first and second
force peaks, and loading and unloading rates of the vertical ground-reaction
force were measured for both limbs. These parameters were predictive for quantification
of gait asymmetry. The asymmetry of these parameters increased as the limb-length
inequality increased. In general, a limb-length inequality >2.0 cm (3.7%)
resulted in gait asymmetry that was greater than that observed in the normal
population. However, the amount of asymmetry varied for each individual. A static
examination can document an anatomic deformity, but this deformity may be compensated
for by functional adaptations. An analysis of the patient's gait should be performed
to identify asymmetries during ambulation. Dynamic gait findings, such as demonstrated
in this study, are needed to support static measurements.