Efeito de um programa de fortalecimento de tronco e quadril sobre os acoplamentos pelve-coxa e pelve-perna no plano transverso na marcha de mulheres jovens saudáveis

Abstract

The pattern and stability of couplings between segments can help to understand how the motor system organizes itself in the face of the task demands. Several studies have shown the relationship between couplings’ patterns and stability with movement health, differentiating injured from healthy populations. Lower limb rehabilitation programs have successfully used hip and trunk strengthening protocols to cause distal changes. Non-local hip and trunk strength training effects probably occur due to the biomechanical coupling between segments. However, no studies demonstrate whether the coupling patterns or coupling stability can be changed, during task execution, following the strengthening of these muscles. Objective: This study aimed to verify the effect of a hip and trunk strengthening program on the pattern and stability of the coupling between the pelvis and thigh and pelvis and shank in the gait of healthy young women. Materials and method: Data from 52 subjects (27 in the control and 25 in the intervention groups) were analyzed in a controlled, non-randomized trial. The intervention group performed an eight-week hip and trunk strengthening training. Muscle performance was operationalized as the concentric and eccentric works and evaluated by an isokinetic dynamometer. An active three-dimensional motion analysis system collected kinematic gait data. The coupling pattern and stability were operationalized as the Absolute Mean Relative Phase (MARP) and Deviation Phase (DP) for the pelvis-thigh and pelvis-shank pairs. Results: The mixed analysis of variance (ANOVA) revealed that after the intervention: 1) the concentric and eccentric hip works increased (factor "interaction time/group" p < 0.001); 2) pelvis-thigh coupling pattern became more in-phase in the walking mid-stance for both groups during full, mid, and final stance (time factor p = 0.009, p = 0,002, p = 0,038 respectively); 3) pelvis-thigh coupling stability increased at middle and final stance (time factor p = 0.044, p = 0,028 respectively). Pre-post intervention period contrasts showed 4) greater pelvis-thigh MARP changes in the intervention group at entire stance (intervention group: p = 0.024, dz = 0.427, control group: p = 0.135, dz = 0.322) and mid-stance (intervention group: p = 0.007, dz = 0.618, control group: p = 0.073, dz = 0.329) and 5) greater pelvis-thigh DP changes at the intervention group at mid-stance (intervention group: p = 0.024, dz = 0.406, control group p = 0.577, dz = 0.087). ANOVA revealed no significant difference in the pattern or stability of the pelvis-shank coupling after the intervention. Conclusion: The results suggest that the hip strength and tissue changes produced by the strengthening program made the pelvis-thigh coupling more in-phase and more stable. There was no distal propagation of these effects.