Proposição, validação e aplicação de um novo metodo para analise cinematica tridimensional da movimentação da caixa toracica durante a respiração / Proposition, validation and application of a novel method to the 3D kinematical analysis of the rib cage motion during breathing

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The present work aimed to propose and validate a novel method to the 3D kinematical analysis of the rib cage motion during breathing and to show an example of application. The kinematical analysis was used to describe the 3D motion of the ribs during breathing. The 3D coordinates of surface markers positioned on the ribs, sternum and vertebrae were used to calculate the transversal and anterior-posterior distances of the rib cage and the orientation of the ribs in function of time. The method identified a signal coherent with the breathing cycle for all the distances measured and for the angles of the ribs around the quasi-transversal axis representing the upward and downward movements of the ribs. The method was also able to identify the higher variation of the transversal and anterior-posterior distances of the rib cage during breathing at vital capacity when compared with breathing at tidal volume. Some tests were performed to evaluate variables related to the measurement errors of the system. Magnetic resonance images of the trunk were used to calculate the relative motion between the surface markers and the ribs (soft tissue artifact). The results revealed less than 1 mm of systematic error and a experimental standard deviation of 2.5 mm, which generate maximal errors of 2º on the angular variation of the ribs. The soft tissue artifact was assumed as the distance between the marker and the rib at total lung capacity minus the distance between the marker and the rib at functional residual capacity, and the absolute mean value found was 3.9 mm. This value is smaller than that one found in the kinematics of other segments. The method was applied in a group of swimmers and a control group of non-athletes and was able to distinguish subjects with a paradoxal movement and showed that swimmers presented greater angular variation for all ribs, and greater correlation between the curves of the rib angles (p<0.05). The swimmers also presented higher correlation between the angular variation of the ribs and the variation of the separate volumes of the trunk. In conclusion, this study has validated the use of 3-D kinematic analysis to evaluate the movement of the ribs and their coordination during breathing as well as has shown its potential to identify differences in the behavior of the ribs motion, showing that swimming training induced an optimized pattern of motion of the rib cage.

ASSUNTO(S)

testes respiratorios videogrammetry cinematica brething rib cage biomecanica torax

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