Rebound Therapy on Ventilatory Functions in Down Syndrome

Inclusion Criteria: * Children ages will be ranged from 9 to 13 years old. * Mild and moderate mental retardation with IQ level between 50-70 based on Stanford-Binet intelligence scale. * Functional hearing and vision. * Independent standing and walking. Exclusion Criteria: * Symptomatic pain. * Musculoskeletal problems or/ atlanto-axial instability. * Rheumatic and congenital heart disease * History of previous surgical operation * Regular participation in any sport activities.