Using challenging surfaces of gait training, which require constant adjustments of the body's movement patterns to maintain stability and provide different sensory and proprioceptive inputs to mimic real life situation is appropriate for children with CP. So, the purpose of the current study is to investigate the influence of surface characteristics of gait training on gait kinematics and walking capacity in children with diplegic CP.

The purpose of the study is to determine the influence of surface characteristics (different surfaces materials and textures) of gait training on kinematics gait parameters (step length, step width, double support time and cadence) and the functional walking capacity in children with diplegic CP.

Inclusion Criteria:

1. Their ages will range from 6 to 8 years old.
2. The degree of spasticity will range from grade 1 or 1+ according to Modified Ashworth Scale.
3. They will be at level II on GMFCS .
4. They will be able to follow verbal command or instructions.

Exclusion Criteria:

• 1. Fixed deformities of lower limbs. 2. Sever visual or auditory problems. 3. History of surgical interference in lower limbs less than one year. 4. Botulinum toxin injections to the lower limb during the previous 4 months.