The Study of Biomechanical Gait Cycle and Balance Characteristics in Intellectual Disabilities: A Systematic Review

Purpose: Gait and balance are functionally related to motor performance. This study aimed to determine biomechanical features of gait in people with intellectual disabilities by reviewing articles published from 1992 to 2017. Methods: In this systematic review, all quantitative studies related to gait and balance of people with intellectual disabilities were searched from Persian databases (Magiran, Irandoc, IranMedex, MedLib, SID, and Google Scholar) and all full text articles with keywords of “intellectual disability”, “balance”, “postural control”, and “gait” were extracted from English databases (Science Direct, PubMed, EMBASE, Cochrane Review, TRIP, Pedro, CINAHL, ProQuest). Then, after complete review of articles, the English and Persian published papers on biomechanical parameters of gait cycle and balance in intellectual disabilities and related factors were extracted. Also, a “Data Extraction Form” which was developed based on research objectives, was used for data collection. Out of 56 related papers and research projects, 20 articles were excluded due to lack of meeting the inclusion criteria. Finally, 36 papers and research projects were included in this study. Results: Of the 36 remained studies, the results showed that intellectual disabilities are usually accompanied with gait disorders, especially in step length, stride length, shorter step width, and lower velocity. It also has kinetic and kinematic disorders, including reduction of the ankle production power in the push-off phase, increased hip and knee flexion at stance phase, knee limitation and plantar ankle flexion at the heel contact, and joint stiffness during the gait cycle. The results showed that individuals with intellectual disabilities had significantly lower scores in the balance tests compared to their healthy peers. Conclusion: Based on the results, the prevalence of gait disorders and balance in people with intellectual disability is high. Preventive measures should be taken in order to control gait disorders and balance. Therefore, it is suggested that occupational therapists, physiotherapists, sports experts, nurses, and other stakeholders try to find therapeutic strategies for preventing, control, and treatment of gait disorders. Also, because of the lack of intervention studies, future research must move from description to intervention studies in order to provide a guideline in clinical settings.