COMPARATIVE CHARACTERISTICS OF THE VERTICAL BALANCE OF CHILDREN'S BODIES WITH DIFFERENT STATURE IN CASE OF PECTUS EXCAVATUM

BACKGROUND: Currently, the biomechanics of not only the chest but also the entire body is being studied to comprehensively understand the multi-link mechanism of functioning of organs and systems in children with pectus excavatum.
AIM: To study the dynamics of postural reactions in children with asymmetric pectus excavatum at the stages of rehabilitation treatment, depending on the body mass index.
MATERIALS AND METHODS: Two groups of patients of both sexes aged 13-16 years with left-sided pectus excavatum were formed, and they underwent clinical, radiological, and stabilometric examinations. The first group included 18 patients with an asthenic body type, whose body mass index was less than 18.50 kg/m2. The second group included 15 normosthenic children, whose body mass index exceeded 18.50 kg/m2 but did not reach 24.99 kg/m2. The data obtained were compared with the indicators of 20 healthy children of the same age who had a normal value of the body mass index.
RESULTS: Based on the combination of stabilometric indicators, patients in both groups had impaired vertical balance before surgery, which was more pronounced in asthenics. It is assumed that in all patients, compression of the pericardium of the deformed sternum led to changes in the characteristics of the neural signals coming from its proprioceptors, causing changes in the postural control system. After corrective surgeries, normosthenic patients showed a more pronounced improvement in vertical body balance compared to asthenic patients. The achieved quality of balance function was 83% and 78%, respectively (p<0.05), which can be explained by the variability of the adaptive capabilities of the postural control system in patients with different body mass index values. 
CONCLUSIONS: Patients with pectus excavatum who have a low body mass index require a personalized rehabilitation approach after undergoing minimally invasive interventions to correct the deformity. This approach aims to facilitate the recovery of children in the postoperative period and promote the normalization of their postural balance.