Gait simulation in children with cerebral palsy using a three-dimensional neuromuscular skeleton model

Abstract

Cerebral palsy (CP) causes abnormal gait pattern due to increased stretch reflex and contracture in specific muscles. Increased stretch reflexes in CP are caused by increased activation of muscle spindles due to increased sensitivity of gamma motor neurons. Furthermore, these neurological abnormalities may cause abnormal postures such as crouching and scissoring. This study aimed to construct a system for supporting treatment and orthosis development in patients with CP by simulation using a three-dimensional neuromuscular skeleton model and evaluate the validity of motor function due to CP reproduced by gait simulation. By reproducing motor function due to CP, the simulation system was able to obtain gait and muscle activity patterns similar to the actual ones. Therefore, motor function in CP can be quantitatively evaluated using this simulation system. In the model of children with CP, gait factors and joint angles of hip, knee, and ankle resembled those of the experimental results; however, the results of muscle synergy analysis were different. Hence, although gait pattern might be highly involved in the enhancement of stretch reflex and muscle contraction, muscle interaction and single muscles influence muscle control in CP.

Keywords

• human dyanamics
• biomechanics
• cerebral palsy
• stretch reflex
• muscle contraction
• three-dimensional neuromuscular skeleton model
• gait simulation