Introduction: Trisomy 21 (Down syndrome) is the most common genetic disorder, which is caused by a chromosomal abnormality and presents various deviations in areas such as mental and motor levels. The presence of extra information corresponding in whole or in part to chromosome 21 affects the development of children with trisomy 21, and abnormal gene expression leads to changes in brain function. The overall prevalence of the syndrome is one (1) to two (2) per thousand (1,000) live births, although the prevalence may have variability among racial or ethnic groups. The purpose of this research is to highlight the deviations in the balance ability, the strength of the upper limbs, and to what extent they affect the quality of life of children and adolescents with trisomy 21. Methods: Eighteen (18) children and adolescents with trisomy 21 participated in the research, with three (3) being excluded due to exclusion criteria. Fifteen (15) children and adolescents with trisomy 21 were finally included, of which four (4) were boys and eleven (11) were girls.