Background and Aim: The aim of this research was to study spinal abnormalities ( kyphosis, lordosis and scoliosis ) and dynamic and static balance in mentally retardation with and without Down syndrome (DS) and relation between them in DS.

Materials and Methods: Thirty mentally retardation with DS (age 13.96 ± 1.77 yr) and 30 mentally retardation without DS (age 14.30±1.96 yr) that selected randomly participated in this study. Modified single balance test for the evaluation static balance and heel-to-toe test for evaluation dynamic balance were used. Continued spinal abnormalities included kyphosis, lordosis and thoracic & lumbar scoliosis were measured by spinal mouse.

Result: The results showed a significant difference between static and dynamic balance, kyphosis and thoracic & lumbar scoliosis in mentally retarded with and without DS . There was a significant relationship between static balance and kyphosis and thoracic and lumbar scoliosis and dynamic balance with kyphosis and thoracic and lumbar scoliosis in DS . There was not a significant relationship between balance and lordosis.

Conclusion: Due to relationship between postural and balance and special needs in mentally retardation particularly Down syndrome, for optimal performance of their daily activities, it should emphasis to recognize the structural profile and prescribe postural corrective programs and improving balance.

Key words : Down syndrome, Spinal deformities, Static balance, Dynamic balance