1. Introduction
CP is a syndrome characterized by poor control of movement and posture, which appears early in life and is considered as the most common cause for children handicapping representing nearly 2 per 1000 live births. The most common form of CP is spastic diplegia and in this form both legs are more involved than the arms so that walking ability is affected. The imbalance of muscle strength and tone causes muscle weakness and atrophy over time, as well as soft tissue contracture and eventual joint deformity. Children with spastic diplegia usually walk independently but most have gait disorder that is known as spastic diplegic gait which includes walking with plantar flexed feet, flexed hips and knees and an anteriorly tilted pelvis with exaggerated lumbar lordosis .This gait disorder makes them walk at a decreased speed with high energy expenditure and restricted functional capability when compared with their healthy peers .
Improving the ability to walk or perform other functional activities is often the primary therapeutic goal for spastic diplegic children . Adaptive equipment that try to compensate for reduced mobility consume a large proportion of the costs related to CP , thus measures that improve mobility in children with CP could potentially result in substantial savings for health care systems.