Three-Dimensional Gait Analysis of School-Age Children With Angelman Syndrome: A Case–Control Study

Gait disturbance is a common motor symptom in Angelman syndrome (AS), but its characteristics have been poorly studied quantitatively. This study aimed to analyze gait characteristics in school-age children with AS using three-dimensional gait analysis (3DGA). Patients with clinically and genetically confirmed AS and healthy children aged 6–15 years were included. For gait assessments, 3DGA was performed using an eight-camera motion analysis system and eight force plates. Gait metrics, including gait speed, step length, step width, gait variability, gait deviation index, and kinematic and kinetic data of lower extremity joints were compared between the groups. Eight children with AS and 24 healthy controls were evaluated. Seven children with AS had flat feet. While step length and gait speed were similar between groups, children with AS showed greater variability in these parameters and larger step widths. Their average gait deviation index was 74.5, indicating significant gait disturbance, and characteristic features included anterior pelvic tilt, insufficient hip extension, excessive knee flexion during early stance, and reduced ankle joint power. School-age children with AS exhibit unstable, prancing gait characterized by knee flexion in the early stance phase, quantifiable using 3DGA. These findings provide foundation for evaluating therapeutic interventions.