ISSN:1422-6405    

DOI:10.1159/000147424

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:1422-6405    

DOI:10.1159/000147425

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Gait analysis plays a major role in the clinical evaluation of equine lameness. It is generally accepted that the clinician expresses the grade of lameness as a subjective score. In this study lameness was objectively assessed using a standardized transient lameness model, in which lameness was induced by intra-articular injection of bacterial endotoxin into the radiocarpal joint of ponies. Lameness was scored by an experienced clinician, and locomotion was recorded simultaneously using a CODA-3 apparatus. The obtained kinematic gait parameters correlated well with the clinical lameness score and also provided possibilities to objectively study the locomotor disturbances of the lame limb in more detail at the walk and trot.

ISSN:1422-6405    

DOI:10.1159/000147426

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The purpose of this study was to compare the velocity-dependent changes in stride length and stride frequency of horses performing the same incremental exercise test first on a track with a rider and then on a treadmill with a 0 and 3.5% slope successively. Seven French saddle horses undertook the exercise test which consisted of 5 stages of increasing speed for 3 min each with 1 min rest between each stage (1.6, 4.2, 8.3, 9.2 and 10 m/s). The horses were recorded by use of a video camera, and the tapes were analysed with regard to gait parameters. At 1.6, 8.3, 9.2 and 10 m/s, stride frequencies were significantly (p < 0.01) greater on the track than on the treadmill. At the walk, stride length was significantly (p < 0.01) shorter on the track than on the treadmill. There were strong linear relationships between stride length and speed in all experimental conditions (R2 0.96). The comparison of the regression coefficients revealed significant differences (p 0.01) influence stride parameters.

ISSN:1422-6405    

DOI:10.1159/000147427

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Multi-body models of musculoskeletal systems can be used to determine internal forces from measured external forces and movements (‘inverse dynamics’) and to perform simulations of movements using muscle forces or activations as input (‘direct dynamics’). Examples of ‘direct’ simulations of movements in the horse are presented. With a model of the equine hindlimb, the function of the ‘passive stay apparatus’ could be explained. A model of the forelimb was used to determine force distributions in the digital flexor tendons, and to experiment with various methods to change the force distribution. Simulations of this type are valuable tools in basic research on functional anatomy and aetiology of injuries. An application with much future potential is the optimization of sports performances using sim

ISSN:1422-6405    

DOI:10.1159/000147428

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

In the hindlimb of quadrupeds three major segments can be distinguished which can rotate with respect to each other in the hip, knee and ankle joints. Movements in a sagittal plane appear to be controlled by three sets of antagonistic mono-articular muscle groups (one set per joint) and two sets of antagonistic bi-articular muscles. This design allows co-activations of mono-articular agonists and their bi-articular antagonists. These co-contractions occur for example in ballistic tasks such as jumping where the transfer of angular acceleration in the joints into the translational acceleration of the hip decreases as a function of joint extension. Well-trained humans appear to solve this problem by a distinct proximodistal sequence in the timing of the joint extensions and a transport of energy via bi-articular muscles. This can also be observed in a number of animals. A second example has to do with the necessity for a certain distribution of net moments in the joints which is required to control the direction and magnitude of the external force on the ground. The control of these moments can to a large extent be judged as a requirement which is independent of the joint displacements required in the same task. Many walking, running or pulling tasks, for example, require knee extension combined with a net knee flexing moment. Co-activation of mono-articular agonists and their bi-articular antagonists appear to solve these problems in an effective and efficient way.

ISSN:1422-6405    

DOI:10.1159/000147429

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The purpose of this study was to compare the damping effect of 16 types of shoeing by measuring hoof acceleration parameters on two trotting horses. At impact, maximal deceleration had extreme values such as 188 m/s2(± 55) for the most damping combination (p < 0.01) and 746 m/s2 (± 14) for the steel shoe (mean = 551 m/s2 ± 125). After the shock, the hoof was exposed to a mean vibrating acceleration at 418 Hz (± 84) which was progressively damped in 37.3 ms (± 10.5). According to these results, the damping ability of different farriery products significantly reduces (p < 0.05) shocks and vibrations at hoof impact in the athletic horse caused by runs on asphalt or similar surfaces. In practice, the use of the most efficient shoeing should help to reduce the incidence of the overused joint diseases in the athletic horse caused by runs on hard surf

ISSN:1422-6405    

DOI:10.1159/000147430

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

To further develop objective methods in the field of gait analysis a force-measuring horseshoe (FM shoe) has been developed. The ground reaction forces were determined by measuring the degree of displacement between the two solid parts of the shoe. This was done by three removable measuring units (MUs) that were equipped with strain gauges and placed in the toe and in each of the quarter parts. Before performing force recordings the sensors were calibrated with the actual MUs mounted on the shoe. This can be done in the field with a specially developed equipment. The shape of the signal generated by the MUs corresponds very well to signals generated by other instrumented shoes and force plate traces reported by other authors. In a comparative study between the FM shoe and a force plate a good resemblance between force traces from the two systems was seen. There is still some work to be done to refine the method of calibrating the FM shoe. However, the good linear relationship between forces applied and the sensor signals implies that the concept of the FM shoe will fulfill the requirements of measuring absolute forces.

ISSN:1422-6405    

DOI:10.1159/000147431

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

A procedure is described by which the length of a tendon at the onset of loading is determined objectively. The procedure includes the fitting of third-order polynomial functions on the load-elongation data. The onset of loading is detected by an increasing fit of the polynomial by selective data reduction of the initial part of the load-elongation curve. The procedure results in an objective and reproducible definition of the zero strain level of a tendon.

ISSN:1422-6405    

DOI:10.1159/000147432

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Animal performance can be determined by subjective observations or objective measurements. Numerical data are only then superior to results of subjective observations when they are the result of measurements carried out to test a well-defined hypothesis or to give the answer to a clear, precisely formulated question. In the analysis of kinematics a careful evaluation of the set-up of the measurement equipment and the resulting accuracy in the data is required. Measurements in three dimensions (3D) are theoretically better than those in 2D. Practically, however, collection, analysis, interpretation and presentation of 3D data are so much more complicated that frequently 2D analysis appears to be more useful. The minimal size of markers necessary to obtain a certain accuracy in kinematic data is usually too big for practical use. Smaller markers impair accuracy. Reduction of measurement noise is obligatory when time derivatives are to be calculated. Skin movement artefacts cannot be removed by data smoothing. Forces occurring between the digits and the ground can be determined using a force plate or an instrumented shoe. A force plate is accurate, but repeated trials are necessary. Using a force shoe each ground contact results in useful data. However, the shoe itself may affect locomotion. Surface strains on long bones can be recorded relatively easily. Determination of loading forces from surface strains is complicated but can be carried out using multiple strain gauges and a post-mortem calibration test. Strain in tendons is difficult to measure due to problems in defining a ‘zero’ or reference length. Tendon forces can either be calculated from signals of parallel, compliant transducers or estimated by application of tendon buckles or wedge-shaped implantable transducers. In both cases a calibration procedure is required to convert transducer signals to tendon for

ISSN:1422-6405    

DOI:10.1159/000147433

出版商:S. Karger AG    

年代:1993

数据来源: Karger