Abstract
Objective This study evaluated and determined, through instrumented three-dimensional (3D)
gait analysis, the kinetic, kinematic, and electromyographic profile of patients with
mucopolysaccharidosis (MPS) IV and VI.
Methods This crossectional study included 11 patients treated at a rare diseases reference
service and evaluated in a movement analysis laboratory. We collected clinical, physical
examination, and kinetic, kinematic, and electromyographic data using a 3D movement
system, from June 2020 to January 2021.
Results There were 5 (45.5%) female patients, and 6 (54.5%) males. Furthermore, 9 (81.8%)
subjects had MPS VI, and 2 (18.2%) had MPS IV. Their average age was 14.6 years. The
average speed was 0.68 m/s (±0.21), and the stride length was 0.66 (±0.15). The most
altered static angles were the hips' abduction-adduction, knees' range of movement,
and foot's progression angle. Most cases presented a gait pattern of hip flexion-adduction
and knee flexion. The gait profile scale (GPS) was 14.58 (±6.72) on the right side
and 11.71 (±3.39) on the left. The gait deviation index (GDI) was 73.23 (±14.50) on
the right side and 80.45 (±17.05) on the left. Muscle activity approximately followed
the current model.
Conclusion The patients showed a decreased average speed and stride length. Most cases presented
a gait pattern of hip flexion-adduction and knee flexion. Both GPS and GDI showed
a significant deviation from normality.
Keywords
electromyography - kinematics - kinetics - mucopolysaccharidoses - three-dimensional
gait evaluation
