Introduction
The number of children and youths with disability is increasing
dramatically in the whole world [1]. The World Health
Organization (WHO) classifies general learning disabilities
into mild, moderate, and severe. The definitions of the
degrees of disability are usually expressed in terms of intellectual
functioning or IQ, behavioral competence, and/or the
need for special service [2].
Children with intellectual disability (ID) often have several
characteristics, which hold back their development.They
usually have underdeveloped physical growth, deformation
and retarded movement, and balance. They have less than
average IQ, difficulties with speech, poor memorization,
attention, perception, and thinking skills. They often have
difficulties with social adjustment, which causes them to be
aloof and aggressive and have low esteem and emotional
imbalance. All of these traits play a role in the impediment
of their cognitive advance. Moreover, according toWHO [3]