Biomedical subjects

P Pourcelot

Publications and source records attributed to P Pourcelot.

21 records · Page 2Linked to original sources

PubMedDate not supplied

Concrete use of the joint coordinate system for the quantification of articular rotations in the digital joints of the horse.

A method is detailed allowing the computation of three-dimensional (3D) joint angles. Each joint of the equine digit is modelled as a sequence of three single axis rotary joints. The Joint Coordinate System was used; it involves a specific sequence of cardanic angles. The decomposition of the angles was chosen so that the three elementary angles coincide with the flexion/extension, passive abduction/adduction and lateral/medial rotations. The algorithms and kinematic procedures were described for the equine front digital joints. This method was tested in vitro on four forelimbs. For each limb, angle values were measured while the member was loaded by a press (from 500 to 6000 N). These tests were repeated while a wedge raised one part of the hoof (toe, heel, lateral and medial sides) in order to induce modifications of the angular patterns of the joints. This method allowed a precise quantitative determination of 3D joint movements. The modifications occurring with the wedges are clearly identified and confirm some previously published semi-quantitative observations. Moreover, this method provides a way to collect objective data on the functional anatomy of joints and could be used to study connective shoeing thoroughly. It may be directly applied to other species and may be used by researchers interested in discreet articular movements, especially occurring in other planes than the sagittal one.

Anatomy, Veterinary↗

PubMedDate not supplied

Kinematic symmetry index: a method for quantifying the horse locomotion symmetry using kinematic data.

This study was conducted to evaluate a method for quantifying locomotion symmetry at trot in sound and lame horses. Using a 3D kinematic analysis system, the kinematics of the limb joints of sound and lame horses were recorded. The differences in motion between the left and right homologous joints were then quantified using a symmetry index based on an inter-correlation method. This method was used to calculate the symmetry indices of the vertical displacements and angle-time diagrams of the joints of each horse. In order to evaluate the sensitivity of this method of quantifying the locomotion symmetry, the symmetry indices of horses suffering from the three main types of lameness (forelimb, hind limb and bilateral lamenesses) were compared with those calculated for a reference group of clinically sound horses. The symmetry indices calculated using this method were sensitive enough to distinguish different degrees of lameness. Except for symmetrical bilateral lameness, the indices obtained also allowed us to determine which of the fore or hind limbs were lame. The results of this study make it possible to consider potential applications of this method in research and clinical fields.

Animals↗

PubMedDate not supplied

Kinematics of the equine back: a method to study the thoracolumbar flexion-extension movements at the trot.

This study was conducted to evaluate a method for quantifying the flexion-extension movements of the back of horses trotting on a track in the conditions of the clinical lameness examination. Using a 3-D kinematic analysis system, the successive positions of four markers placed at regular intervals between the withers and the tuber sacrale were recorded. To isolate the flexion-extension movements of the back, the positions of these four markers were recomputed in a trunk-related co-ordinate system of the horse. Then, for each frame, the equation of the third-order polynomial that best fitted the position of the four markers was determined. Using these equations, it was then possible to interpolate the vertical displacement of any point situated between the withers and the tuber sacrale. The accuracy of this method was evaluated using three additional markers placed between the four previous ones. The vertical displacements of these three markers were recorded and compared to the interpolated displacements provided by this method. The results showed that the experimental and interpolated values did not present any statistical difference except in the lumbar region. In this region, the general shape of the vertical displacement curve was conserved but magnified by 17%. This study showed that despite the weakness of the range of the flexion-extension movements of the equine back at trot, these movements can be quantified with reliability. This method was then used on a lame horse. The results obtained demonstrated the usefulness of this method to study the flexion-extension movements of horses suffering from various locomotor disorders.

Animals↗