Análise dos momentos articulares no gesto da mudança de direção em saltos

Abstract

Objective: To analyze if joint contribution of moment production differs between the hip, knee and ankle joints in an unexpected change of direction. Materials and Methods: 10 male participants [mean (SD): 24(3) years old, 79.5(0.7) kg of body mass and 1.77(0.03) cm of height] without lower extremity injuries performed an unexpected change of direction upon landing from a vertical jump. The side was indicated on the panel with a light in front of them. The panel light was turned on during the flight phase, indicating the direction change side. Fifteen infrared cameras captured the movement (Bonita B10, Vicon Motion Systems, Oxford, Reino Unido, sampling at 200 Hz) and 2 force plates recorded the kinetic data (OR6-2000, AMTI Inc., EUA, sampling at 2 kHz). Three trials were recorded for each side in randomized order. The absolute sum of joint moment in the sagittal and frontal plane was estimated and each joint's relative contribution was identified. The comparison between joints during landing and propulsion of change of direction was placed on data series when the confidence intervals did not overlap. The local ethics and research committee approved this study (CAAE 96793518.3.0000.5323). Results: The ankle presented a higher contribution to moment production in the sagittal plane, while the knee and hip were in the frontal plane during a change of direction after landing from a jump. The joint moment combination in different planes of motion reflects the mechanical demand of change of direction required to provide stability and propulsion during the execution of high-speed motion. Conclusion: Unexpected change of direction leads to different demands in sagittal and frontal planes, showing a higher contribution of ankle and knee, respectively. These results help decision-making for training and injury prevention in sports involving a change of direction.