Análise da influência do gird na biomecânica e no desempenho neuromuscular do complexo do ombro em atletas de arremesso

Abstract

The throwing movement imposes an excessive stress on the glenohumeral joint, since during these movements a very high angular velocity is generated, causing this joint to suffer with great traction forces. Repeated performance of such movements generates some bone, joint capsule and muscle adaptations that culminate in the development of the posterior stiffness of the shoulder and the Glenoumeral Internal Rotation Deficit, known as GIRD. As a consequence of these deficits, there is an association of a decreased range of motion (ROM), imbalance of muscle strength between medial and lateral rotators and shoulder proprioception, which increases the risk of osteomyoarticular lesions. The objective of this study was to analyze the biomechanical adaptations and the neuromuscular performance of the shoulder complex of athletes with and without GIRD. It was an observational cross-sectional study of 61 athletes practicing handball and beach handball (34 males and 27 females, 27.03 ± 5.99 years, BMI 25.58 ± 3.84) and 23 non-athletes (11 men and 12 women, 26.26 ± 4.32 years, BMI 23.61 ± 2.78). There were evaluated: ROM for medial (MR) and lateral (LR) rotations and horizontal shoulder adduction (HA); sense of joint position of shoulder during ROM of LR, both using an Accumar® digital inclinometer; and isometric ROM of LR and MR strength using a Lafayette® manual dynamometer for both groups (athletes and non-athletes). Based on the ROM for MR evaluation, athletes with shoulder differences between limbs of less than 10º were allocated to the group without GIRD (44 individuals) and those with a difference greater than 10º in the group with GIRD (17 individuals). The statistical analysis used was one-way ANOVA for all demographic variables, for comparison between groups with GIRD and without GIRD and difference between the dominant shoulder (DS) and the non-dominant shoulder (NDS) for the ROMs (MR, LR and HA). Two-way ANOVA was used for comparison between groups with and without GIRD and members (DS and NDS), for the variables ROM of MR, LR, total and HA, sense of joint position, RM and RL strength and LR/MR force ratio. Only for the isometric strength variables, comparisons were made between the three groups (with and without GIRD and non-athletes). And, when necessary, the post hoc tests of Tukey were employed. P <0.05 was considered. As a result, interaction was verified for the ROM of MR variable (p <0.01), where the DS of the with GIRD group presented lower ROM of MR in relation to both members (DS and NDS) of the group without GIRD. For the ROM of LR variable, with the GIRD group had higher ROM of LR (p = 0.03), and in both groups a lower ROM of HA was observed in the DS (p = 0.005). For the SPA variable there was no difference between members nor between groups. In the assessment of strength in the three groups (with and without GIRD and non-athletes) the MR and LR strength was higher in the group of athletes compared to non-athletes for both muscle groups (p<0.01 and p=0.01), and the force ratio in the non-athletes group in relation to the without GIRD group only (p<0.01). Among the members there was a higher LR strength in the DS in all groups ((p=0.02). Despite the differences in glenohumeral rotation ROM, GIRD athletes did not show differences in ROM of HA, sense of joint position and shoulder rotator strength when compared to without GIRD athletes. However, regardless of GIRD, the dominant shoulder presents greater posterior stiffness and athletes, in general, present higher MR and LR strength than non-athletes.