EVALUATION OF A NONINVASIVE THREE-DIMENSIONAL MODEL OF THE HIP JOINT IN SOUND SHEEP

Abstract

The aim of this study is to develop and validate a local three-dimensional coordinate system to characterize the motion of the hip joint in healthy sheep during walking. The hypothesis is that the model created will allow a noninvasive evaluation of this joint and the data collected may be useful in studies that require follow up of the joint motion. Eight healthy sheep of similar size, intact, female, aged from 2 to 4 years will be used. Before start data collection, the sheep will be trained to be conducted to walking in a pre-determined space at constant velocity. Kinematic data will be collected by use of an 8-camera system. A minimum of 5 valid trials will be analyzed and normalized by Nexus motion-analysis program (Vicon) for graphic elaboration. Angular velocity (maximum, minimum) will be calculated for flexion/extension and joint angles (maximum, minimum, displacement) will be calculated for internal/external rotation, abduction/adduction and flexion/extension of both hip joints. All kinematic data will be evaluated for normality with the Shapiro-Wilk test. The mean and standard deviations, or median and interquartile range will be calculated. To compare left and right sides, the kinematic data that pass the normality test will be analyzed by means of Student's t-test. Data that do not pass the normality test will be analyzed by a Mann-Whitney U test. Differences will be considered statistically significant with p <0.05.