Frontal and Sagittal Plane Biomechanics During Drop Jump Landing in Boys Who Are Obese

Abstract

To investigate the frontal and sagittal plane lower extremity biomechanics during drop jump landings in boys who were obese and boys who were of healthy weight. Twelve boys participated, 6 were considered as healthy weight (body mass index for age <85%, age 11.0 +/- 0.8 years), and 6 were considered as obese (body mass index for age >95%, age 12.1 +/- 0.7 years). Three-dimensional data were collected during landing from a drop jump. Group means were compared using Student t tests (alpha = 0.05). Significant differences were found in peak hip adduction moment, timing of peak dorsiflexion and knee flexion angles, and timing of peak knee extension and abduction moments. Boys who were obese exhibited significant differences in frontal and sagittal plane biomechanics when landing from a jump compared with healthy weight peers. These differences could place boys who are obese at greater risk for lower extremity injuries when they engage in jump-landing activities.