It will be hypothesized that strengthening the calf muscles will improve standing efficiency in children with spastic diplegia.

Inclusion Criteria:

• Children age will be ranging between 2 and 4 years.
• They are classified at level III by GMFCS-ER, i.e. they can stand with minimal support.
• Full mobile lower limbs joints.
• Children with mild and moderate spasticity ( i.e. grade 1 and 2, according to Modified Ashworth Scale).

Exclusion Criteria:

• Children with severe spasticity ( i.e. grade 4, according to Modified Ashworth Scale).
• Fixed deformities.
• Uncontrolled seizures.