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C Degueurce

Publications and source records attributed to C Degueurce.

At least 19 recordsLinked to original sources
PubMed2006

Three-dimensional kinematics of the distal forelimb in horses trotting on a treadmill and effects of elevation of heel and toe.

REASONS FOR PERFORMING STUDY: Comprehensive understanding of the 3-dimensional (3D) kinematics of the distal forelimb and precise knowledge of alterations induced by dorsopalmar foot imbalance remains incomplete because in vivo studies performed with skin markers do not measure the actual movements of the 3 digital joints. OBJECTIVE: To quantify the effects of 6 degree heel or toe wedges on the 3D movements of the 4 distal segments of the forelimb in horses trotting on a treadmill. METHODS: Three healthy horses were equipped with ultrasonic markers fixed surgically to the 4 distal segments of the left forelimb. The 3D movements of these segments were recorded while horses were trotting on a treadmill. Rotations of the digital joints were calculated by use of a joint coordinate system. Data obtained with 6 degree heel or toe wedges were compared to those obtained with flat standard shoes. RESULTS: Use of heel wedges significantly increased maximal flexion and decreased maximal extension of the proximal (PIPJ) and distal (DIPJ) interphalangeal joints. Inverse effects (except for PIPJ maximal extension) were observed with the toe wedges. In both cases, neither flexion-extension of the metacarpophalangeal joint nor extrasagittal motions of the digital joints were statistically different between conditions. CONCLUSIONS: At a slow trot on a treadmill, heel and toe wedges affect the sagittal plane kinematics of the interphalangeal joints. POTENTIAL RELEVANCE: Better understanding of the actual effects of toe and heel wedges on the 3D kinematics of the 3 digital joints may help to improve clinical use of sagittal alteration of hoof balance in the treatment of distal forelimb injuries.

Animals↗
PubMed2005

Three-dimensional kinematics of the equine distal forelimb: effects of a sharp turn at the walk.

REASONS FOR PERFORMING STUDY: Sharp turns are suspected to increase expression of several distal forelimb lamenesses even at the walk but the biomechanical consequences of such a movement remain unknown. OBJECTIVE: To quantify the effects of a sharp turn at the walk on the 3-dimensional movements of the distal segments of the forelimb. METHODS: Kinematics of the distal segments were measured in 4 healthy horses invasively with an ultrasonic system. Three-dimensional rotations of the digital joints were calculated by use of a joint coordinate system. Data obtained for a turn at the walk were compared to those obtained in a straight line. RESULTS: During the stance phase in a turn, the inside forelimb underwent an adduction that induced lateromotion and medial rotation in the distal interphalangeal joint and medial rotation in the proximal interphalangeal joint. These movements were maximal at heel-off and decreased during breakover as the hoof underwent a sudden lateral rotation. CONCLUSIONS: Walking in a sharp turn affects the kinematics of the digital joints outside the sagittal plane. POTENTIAL RELEVANCE: This knowledge offers the opportunity to derive hypotheses on biomechanical factors that could contribute to the pathogenesis of digital injuries and on consequences for rational shoeing.

Animals↗
PubMed2004

In vitro assessment of movements of the sacroiliac joint in the horse.

REASONS FOR PERFORMING STUDY: Sacroiliac joint (SIJ) disease is associated with poor hindlimb action, lameness and poor performance in horses. However, little is known about the biomechanics of this low-motion joint. OBJECTIVES: To determine in vitro the capacities of movement of the SIJ in the sagittal plane, and to test the effect of a sacrosciatic and sacrotuberal desmotomy on its stabilisation. METHODS: Six anatomical specimens underwent cycles of flexion-extension of the lumbosacral joint (LSJ) before and after desmotomy. Kinematic triads were linked rigidly to the sacrum, spinous process of vertebra L5 and iliac wing. Angles were measured using a joint coordinate system based on anatomical frames. RESULTS: The LSJ underwent regular movements of flexion and extension (overall mean +/- s.d. range 23.4 +/- 1.6 degrees). The only recorded movement of the SIJ was a nutation during LSJ flexion (overall mean +/- s.d. 0.8 +/- 0.5 degrees). Desmotomy induced an increase of that nutation (overall mean +/- s.d. 1.7 +/- 0.2 degrees). CONCLUSIONS AND POTENTIAL RELEVANCE: Movements of the SIJ were small and coupled only with the flexion of the LSJ. The ligaments surrounding the SIJ have a strong effect on the stabilisation of this joint. Due to the limited amount of movement, its biomechanical study in vivo seems to be difficult. Further in vitro studies would be useful to determine the role of each ligament, to better understand the clinical consequences of the tears frequently observed during necropsy.

Animals↗
PubMed2004

Effects of 6 degree elevation of the heels on 3D kinematics of the distal portion of the forelimb in the walking horse.

REASONS FOR PERFORMING STUDY: Understanding of the biomechanical effects of heel elevation remains incomplete because in vivo studies performed with skin markers do not measure the actual movements of the 3 digital joints. OBJECTIVE: To quantify the effects of 6 degree heel wedge on the 3-dimensional movements of the 4 distal segments of the forelimb in the walking horse. METHODS: Four healthy horses were used. Kinematics of the distal segments was measured invasively with a system based on ultrasonic triangulation. Three-dimensional rotations of the digital joints were calculated by use of a 'joint coordinate system' (JCS). Data obtained with heel wedges were compared to those obtained with standard shoes during the stance phase of the stride. RESULTS: Heel wedges significantly increased maximal flexion of the proximal (PIPJ) and distal (DIPJ) interphalangeal joints and maximal extension (mean +/- s.d. +0.8 +/- 0.3 degrees) of the metacarpophalangeal joint (MPJ). Extension of the PIPJ and DIPJ was decreased at heel-off. Few effects were observed in extrasagittal planes of movement. CONCLUSIONS: Heel wedges affect the sagittal plane kinematics of the 3 digital joints. POTENTIAL RELEVANCE: Controversial effects previously observed on the MPJ may be explained by the substantial involvement of the PIPJ, which was wrongly neglected in previous studies performed on the moving horse.

Animals↗
PubMed2001

In vitro comparison between a DCP and external fixator for pancarpal arthrodesis in the dog.

Many clinical reports have previously documented the advantages of plates or external fixations but surgeons prefer to use plate for better acceptance by the owner, less dressing and a decreased rate of infection. In order to address complications of carpal surgery, infections, arthritis and osteomyelitis, external fixation is warranted. Twelve canine forelimbs, free of abnormality, were tested under compression to evaluate the in vitro biomechanical behaviour of the normal carpus. This behaviour was compared with that of a stabilized carpus stabilised by panarthrodesis with either plates (8 hole 3.5 mm dynamic compression plate (DCP), or a type II external fixator. Deformation vs. load was recorded after compression with a testing machine in conjunction with a digital data acquisition system. Yield load, maximal load to failure and stiffness were then calculated. Variables were significantly greater for arthrodesis with external fixation and plates than for intact forelimbs. The stiffness and the MLF after stabilisation with plates or external fixators did not differ significantly. At MLF, fracture of the third metacarpus appeared with plates, whereas deformations of the pins and bars of the external fixators increased with load. Stabilisation with plate or external fixation allowed more load to failure than the intact carpus. The biomechanical behaviour of both methods of arthrodesis was identical during loading. However, after rupture, external fixation was more plastic. External fixation, which is less often used than plates for pancarpal arthrodesis, mainly due to the occurrence of sepsis, may be useful for arthrodesis of the carpus in big or active dogs.

Animals↗
PubMed2001

Three-dimensional kinematics of the proximal interphalangeal joint: effects of raising the heels or the toe.

The proximal interphalangeal joint (PIPJ) has always been considered as a low-motion joint with an almost constant angle during loading of the limb. Until very recently, its motion was not taken into account in kinematic studies in vivo. Recent in vivo studies yielded surprisingly high ranges of motion in this joint. The aim of this study was to measure, in terms of the 3 possible rotations (flexion/extension, collateromotion and axial rotation), the movements of the PIPJ in vitro during limb loading in a neutral position (500-6000 N) and after the addition of heel and toe wedges (6 degrees and 12 degrees). The joint coordinate system, as it was recently described for use in the horse, was used to compute the 3 components of rotation. With the hoof in neutral position, low-amplitude flexion movements (7.9 degrees) were observed. They were not associated with collateromotion or axial rotation. The flexion of the joint increased exponentially with load suggesting that, during the midstance phase, heavy loads are necessary to evoke substantial flexion. Raising the heels induced an early flexion of the joint with an increase of its total amplitude. Raising the toe produced an extension at 500 N, beyond which the amount of flexion was reduced. These results show that PIPJ flexion/extension during in vitro loading remains substantially smaller than suggested by in vivo studies based on skin markers. Raising the toe or heel directly affects the behaviour of this joint, but does not induce motion outside the sagittal plane. Hoof wedges are commonly used in clinical practice for purposes other than affecting PIPJ motion. In these cases, their biomechanical effects on this joint should be taken into account.

Animals↗
PubMed2001

Normal three-dimensional behaviour of the metacarpophalangeal joint and the effect of uneven foot bearing.

The purpose of this study was to quantify small amplitude rotational movements in the metacarpophalangeal joint (MPJ) of the horse and to measure the influence of asymmetric placement of the foot on these articular angles. Trihedrons, supporting kinematic markers defining a local frame, were screwed into the third metacarpal bone and the proximal phalanx of 4 isolated forelimbs. The limbs were loaded in a press, and the lateral or medial aspects of the foot were raised alternately by a 12 degrees wedge. The use of the joint coordinate system permitted the simultaneous and continuous computing of the 3 angles of rotation of the joint. During neutral loading, the extension of the MPJ (38.4 +/- 8.7 degrees) was associated with lateral axial rotation of the proximal phalanx (1.8 +/- 0.9 degrees). Addition of a lateral wedge induced medial rotation (-0.9 +/- 0.2 degree) and abduction (2.1 +/- 0.4 degrees) of the proximal phalanx. The opposite phenomenon was observed with a medial wedge. These quantitative results confirmed the combination of axial rotation and widening of the articular space on the opposite side to the raised part of the foot that had earlier been observed in semi-quantitative studies. Despite the high congruence of this joint, this study demonstrated the significant influence of uneven bearing of the foot on the three-dimensional (3-D) behaviour of the MPJ. Even though the amplitude of these movements remained small, their biomechanical effects should be considered to improve our understanding of MPJ injuries and to rationalise exercise management and corrective shoeing in the lame horse.

Animals↗
PubMed2001

Kinematic analysis of the symmetry of limb movements in lame trotting horses.

This study was undertaken to describe the symmetry of movements of fore- and hindlimbs in horses suffering from various spontaneous lamenesses. Two groups of horses were studied: 13 clinically sound horses and 24 lame horses. Using a 3-dimensional (3-D) kinematic analysis system, movements of both sides of each horse were recorded simultaneously while trotting on a track. The differences in motion between left and right homologous joints of each horse were quantified using symmetry indices based on an intercorrelation method. Symmetry indices obtained for each lame horse were then compared with those of sound horses. This comparison showed that the most sensitive lameness indicators were the symmetry indices of the vertical displacement of the proximal markers of the limbs. Symmetry indices of each lame horse were also compared with those of the other lame horses, using correlation coefficients to determine whether or not various lamenesses generate similar alterations of the locomotion symmetry. Values of these coefficients allowed 2 types of lameness to be distinguished. In 21 lame horses, the largest alterations in the symmetry of vertical movements were observed for the proximal markers of the limbs, which may reflect the supporting component of these lamenesses. In contrast, the asymmetries in vertical movements were more pronounced for the distal markers in 3 horses (one stringhalt and 2 carpal injuries), which may reflect the swinging component of these lamenesses. This cross-correlation method can be implemented easily in a computer programme and may represent a first step in the development of an expert system.

Animals↗
PubMed2000

A method to synchronise cameras using the direct linear transformation technique.

The aim of this paper is to present a method which enables the recordings of cameras that are not equipped with a synchronisation system to be synchronised a posteriori. Using the Direct Linear Transformation technique, this method estimates the phase difference between two cameras by minimising the reconstruction errors of a moving point. Once the phase difference value is known, one of the recordings is chosen as a reference and the second one is synchronised to the first by cubic spline interpolation.

Animals↗
PubMed1999

Kinematics of the equine back: flexion-extension movements in sound trotting horses.

This study was undertaken to evaluate the flexion-extension movements of the back in a group of sound trotting horses. Using a 3-D kinematic analysis system, 13 clinically sound horses fitted with 5 skin markers placed on the dorsal midline of their trunk were recorded while trotting on a track in the conditions of the routine lameness examination. These markers were used to calculate 3 back angles (thoracic, thoracolumbar and lumbosacral angle). These back angles were then filtered using Fourier series. To evaluate the repeatability of flexion-extension movements, the intra- and inter-individual variabilities were studied. The angle-time diagrams showed that the equine back extended during the first part of each diagonal stance phase and flexed during the second part of each diagonal stance phase. The ranges of motion were less than 4 degrees for the 3 back angles. The intra- and inter-individual variability values of maximal extension and maximal flexion time points were similar and extremely low. This demonstrates the high repeatability of the temporal pattern of flexion-extension movements of the back. Intra- and inter-individual variabilities of the range of motion showed that the back mobility varies more in-between horses than between trials of the same horse. Compared with electromyographic activities of back muscles reported in the literature, flexion-extension movements described in this study tend to show that, at a slow trot, trunk muscles act mainly to limit flexion-extension movements of the back rather than to induce movements.

Animals↗
PubMed1999

Correlation between surface electromyography and kinematics of the hindlimb of horses at trot on a treadmill.

The purpose of this study was to demonstrate the feasibility of surface electromyography in the horse and to correlate electromyographic activity with kinematic data. Surface electromyography of seven hindlimb muscles was recorded in five horses at trot on a treadmill. Simultaneously, kinematic analysis of the hindlimb was performed using a three-dimensional system and a unidirectional accelerometer was attached to the hoof. Electromyographic activities of the gluteus medius, vastus lateralis and two parts of the biceps femoris started in the late part of the swing phase and ended in the late period of the stance phase or the early period of the next swing phase. The semitendinosus showed two bursts of activity. The tensor fasciae latae acted when the previous muscles were inactive. Activity of the extensor digitorum longus was of low level but lasted during most of the step cycle. Correlation between electromyography, kinematics and anatomy helps us to understand the complex role of biarticular muscles: the tensor fasciae latae flexes the hip joint during the swing phase and extends the stifle joint during the stance phase, whereas the semitendinosus extends the hip joint during the stance phase and flexes the stifle joint during the swing phase. Cranial and caudal regions of the biceps femoris were also found to be bifunctional. Surface electromyography correlated with kinematic analysis gives valuable information about the functions and the timing of activity of the hindlimb muscles.

Animals↗
PubMed1998

Asymmetry in placement of bilateral skin markers on horses and effects of asymmetric skin marker placement on kinematic variables.

OBJECTIVE: To evaluate asymmetry in placement of bilateral skin markers on horses and to determine effect of asymmetric skin marker placement on kinematic variables for trotting horses. ANIMALS: 10 horses for evaluation of asymmetry in marker placement; 1 horse for evaluation of effects on kinematic variables. PROCEDURE: Asymmetry in marker placement was assessed by attaching markers to horses and comparing radiographs of left and right limbs. An experimental model was developed to determine effects on kinematic variables; accuracy of the model was validated experimentally. Using kinematic data from a clinically normal trotting horse as reference data, effects of asymmetric marker placement on vertical displacement-time and joint angle-time diagrams were determined by use of the model. RESULTS: Asymmetry of placement was < 1 cm for markers on the distal portions of the limbs and < 2 cm for markers on the proximal portions. Asymmetric marker placement did not alter general shapes of the vertical displacement-time and joint angle-time curves. In most instances, largest differences in vertical displacement attributable to asymmetric marker placement were equal to or less than magnitude of the asymmetry of placement. Alterations in joint angle-time curves were mainly a result of shifting of the curves on the Y axis. Joint range of motion was only slightly changed by asymmetric marker placement, but maximum flexion and extension angles were greatly altered. CONCLUSIONS AND CLINICAL RELEVANCE: Some kinematic variables can be greatly altered by small differences in skin marker placement. Such effects should be taken into account when evaluating kinematic data for sound and lame horses.

Animals↗
PubMed1997

Variability of the limb joint patterns of sound horses at trot.

The reproducibility of gait variables for sound horses is essential for the interpretation of their modifications by locomotor disorders. Therefore, the purpose of this study was to evaluate the variability of the limb joint angle patterns in a population of sound horses while they trotted in the conditions of the routine lameness examination (slow trot, just held by hand, on a track, outdoors). The kinematics of 14 French Saddle horses was recorded using a 3-dimensional (3D) kinematic analysis system. Angle-time diagrams were established in the sagittal plane and their intra- and inter-individual variabilities were evaluated for the whole stride. Horses spontaneously repeated tests at constant speed. The intra- and inter-individual variabilities were low. These values were different from one joint to another and they increased distally. The maximum values were reached by the fetlock and coffin joints. Inter-individual compared to intra-individual variability was 0.9 to 1.9 times greater. There was a high correlation between mean angle-time and mean individual diagrams established for the whole population. It was concluded that it is possible to repeat similar tests with horses trotting in the conditions of the lameness examination. In an homogeneous population, each horse adopts a constant angular pattern that is very close to that of other horses. Since mean angle-time diagrams established on a sound population are highly representative of each mean individual angle pattern, they can be considered as reference data for the further analysis of the pathological gait.

Animals↗
PubMed1997

Kinematic analysis of the locomotion symmetry of sound horses at a slow trot.

This study of the locomotion symmetry was undertaken to provide standard symmetry indices of a group of sound horses at the trot. Using a 3D data collection system, the kinematics of the limb joints of 13 clinically nonlame horses were recorded while trotting in the standard conditions of the clinical lameness examination. A kinematic symmetry indice based on an inter-correlation method was defined and applied to the vertical displacement-time and joint angle-time diagrams of the left and right joints of the horses. For each horse, the mean symmetry indice of each joint was calculated using values from 5 trials. For each joint, these means were then averaged. To evaluate the repeatability of the locomotion symmetry, the intra- and inter-individual variabilities of the symmetry indices were studied. The levels of symmetry of the markers of the trunk were generally lower than those of the limbs. Moreover, during the 5 trials these levels of symmetry were strongly variable but their mean values were very similar from one horse to another. In our experimental conditions the trunk presented a higher degree of freedom than the limbs. This high intra-individual variability indicated also that several trials are necessary to quantify the locomotion symmetry of a trotting horse. In the same way, a lower level of symmetry of the hindlimbs, compared to the forelimbs, was proved by their lower values of symmetry indices. As opposed to the supporting role of the forelimbs, the propulsive role of the hindlimbs may explain this feature.

Animals↗
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↗