Influence of Limb Length Discrepancy and its Compensation on the Amplitude of Pelvic Motion in the Frontal Plane during Walking: a Prospective Cohort Study of 40 Children

Abstract

INTRODUCTION. Biomechanical abnormalities caused by limb length discrepancy are controversial problems of pediatric orthopedics.AIM. To assess the influence of limb length discrepancy and its compensation in children on the amplitude of pelvic motion in thefrontal plane during walking.MATERIAL AND METHODS. We examined the study group of 21 patients with (the average discrepancy was 2,86% (from 0,23% to6,12%). Biomechanical examination consisted of dynamic optical computed topography. The study was carried out in standard shoesand in shoes with compensation. The average compensation was 14 mm (from 5 to 45 mm). The comparison group consisted of 19healthy children without limb length discrepancy. The angle of frontal asymmetry of the pelvis was calculated as the absolute differencein inclination.RESULTS AND DISCUSSION. When compensation was used, the amplitude of pelvic movements changed insignificantly, by an averageof 1.84°, in children with discrepancy of the lower limbs. In the comparison group (healthy children), we also did not observe anychanges in frontal pelvic oscillation when imitating variability compared to tests without compensation. The most obvious explanationfor this phenomenon is the formation of additional compensation mechanisms for different lengths of the lower limbs.CONCLUSION. Compensation of limb length discrepancy requires an individualized approach and additional walking examinationsof the patient. Further research will expand our understanding of the role of compensation for limb length discrepancy both inconservative treatment and in planning for surgical interventions.

Keywords

• limb length discrepancy
• shoe lift
• heel pad
• pelvic obliquity
• walking
• pediatric orthopedics