Background and Objective: Cerebral palsy (CP) is the most common form of upper motor neuron lesions in the children, leaded to joints deviation and different patterns of walking, like the crouch gait. Therefore, these joints devastation as well as the compensatory mechanisms were altered the mechanical impedance and gait insufficiency in these patients. The aim of this study was to compare mechanical impedance of joints and limb (skeletal and muscular components) at different sub phase of the stance phase of gait in Cerebral palsy crouch gait children.
Methods: Twenty five children with spastic diplegia crouch gait Cerebral palsy and twenty five healthy controls walked at a self-selected comfortable speed. Kinetic and kinematic data were measured and analyzed during the loading response, the mid-stance, the terminal stance and the pre-swing sub phases of gait.
Results: According to our study the Cerebral palsy crouch gait group showed a significant decrease in the leg impedance but increase in the joint impedance during the early to mid stance phase. However, during the terminal stance the leg impedance was increased as a result of more contribution of the muscular component to achieve sufficient impedance, which required increasing the muscular demands for keeping the body posture against collapse.
Conclusion: The results of current study depicted that the Cerebral palsy crouch gait group relied more on the muscular than the skeletal components to achieve the required leg impedance. In addition, the more flexed hip and knee were increased the lever-arm length of the Ground Reaction Force (GRF) vector at the joint centers, thus increased the joint moments.