Variáveis biomecânicas que interferem na performance do Y-Balance Test e Biodex Balance Test

Abstract

Aiming at the prevention and rehabilitation of musculoskeletal injuries, professionals working with sports and health study tests that identify risk factors for injuries and guide the rehabilitation process. The Y Balance Test (YBT) evaluates unipodal dynamic postural stability by measuring the lower limb reaches in the anterior, posterolateral, posteromedial and composite directions. Studies question its validity pointing to the absence of correlations with Biodex Balance System® (BBT) tests. Biomechanical variables of the lower limb may influence these results. The objectives of this study are: to describe and analyze the linear correlations and interactions between these variables and the results of YBT, BBT and between the two tests, in post-LCA subjects. Methods: Cross-sectional study with 70 subjects during March to October 2017 at the Federal University of Ceará. Muscle strength and flexion of knee was measured with isokinetic dynamometer, hip force with HipSIT. Weight-Bearing Lunge Test to assess ADM of ankle DF. Postural stability with YBT and BBT. For linear analysis we used the Pearson correlation coefficient and Classification and Regression Tree (CART) for nonlinear interactions. Results: The biomechanical variables obtained a higher correlation with the injured limb. The BBT indices with the member not injured. Knee extension strength and overall stability index were the main predictors of performance for YBT. There were different non-linear interactions between the biomechanical variables and the BBT indices with the YBT ranges, according to the assessed limb. Conclusion: Biomechanical variables and stability indexes of BBT present different correlation and interactions with YBT dependent on the scopes and limbs tested.