Muscle asymmetry profiles in children with intellectual disabilities and their normotypic peers in the framework of the tеncegrity concept

BACKGROUND: According to various data, individuals with intellectual disabilities have features of the motor sphere development, which are manifested in reduced development of physical qualities, distortion of the formation of movement patterns, and violation of locomotor functions. Considering the body as a single integral structure, the study proposes to identify profiles of motor asymmetries from the position of the tensegrity model, which are characteristic of individuals with intellectual disabilities and individuals with normotypic development. This task is relevant not only from the point of view of physical indicators, but also understanding the influence of the mental and intellectual spheres on the mechanisms of the implementation of the motor act.

АIM: To determine muscle asymmetry profiles in children with intellectual disabilities and their normotypic peers from the perspective of the tensegrity model.

METHODS: The study was conducted in correctional and general education institutions of Yekaterinburg. The study involved 80 children aged 13 years: 40 with mild mental retardation, 40 with normotypic development. Testing was conducted on the biomechanical diagnostic and treatment system Humac Norm (CSMi Medical Solutions, USA). The following muscles were examined: anterior and posterior thigh, hip flexion and extension, ankle flexion and extension, hip abduction and adduction, shoulder flexion and extension, shoulder abduction and adduction. Muscle strength and endurance were assessed, as well as functional motor asymmetries were identified by comparing the test results for different limbs. Statistical analysis was performed using the SPSS program. For a comparative analysis of the 2 groups, the nonparametric one-way Kruskal-Walli’s analysis of variance was used. Quantitative data are described using median, 1^st and 3^rd quartile.

RESULTS: A comprehensive analysis of the group of individuals with intellectual disabilities reveals asymmetry of the sides in the muscles of hip flexion, hip abduction, shoulder adduction, shoulder extension and flexion. In individuals with normotypic development, all values of the deficit of the sides are in the zone of acceptable indicators (up to 20%), without asymmetry of the sides. The data between the groups have statistically significant differences.

CONCLUSION: In individuals with intellectual disabilities aged 13, the asynchronous profile was detected in 62.5% of cases, the lateral profile in 22.5% of cases, and the normotypic profile in 15% of cases. In individuals with normotypic development, the same was true in 12.5%, 15%, and 72.5% of cases, respectively. In cases of intellectual disabilities, reduced muscle performance indicators were detected, which together form the substantive basis for correctional activities that are special in nature for physical development.