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Topic:Locomotion
Locomotion in horses refers to the movement mechanisms that enable horses to walk, trot, canter, and gallop. It involves a complex interplay of the musculoskeletal and nervous systems, allowing for efficient and coordinated movement. Studies on equine locomotion often focus on gait analysis, biomechanics, and the impact of various factors such as conformation, training, and surface conditions on movement. Research in this area contributes to understanding performance, diagnosing lameness, and improving rehabilitation practices. This page compiles peer-reviewed research studies and scholarly articles that explore the biomechanics, gait patterns, and factors influencing locomotion in horses.
A quantitative analysis of skin displacement in the trotting horse. Skin displacement was investigated at 16 sites in the front and hind limbs of four Dutch Warmblood horses at the trot. For visualisation of the bone under the skin, a measuring device mounted on a Steinmann pin driven into the bone under investigation, was employed. Mean displacements ranged from 8 mm (X-displacements proximal and distal metacarpus) to 142 mm (Y-displacement caudal part of greater trochanter). When compared with previously determined skin displacement patterns at walk, mean displacements at trot were of the same magnitude whereas the shape of the time-displacement curve was di...
The effect of an acute hoof wall angulation on the stride kinematics of trotting horses. High speed cinematography was used to describe the stride kinematics in a group of six, sound horses subjected to two farriery treatments, designated 'normal' and 'acute' hoof angulation. Normal was defined as having the dorsal hoof wall aligned with the pastern axis, whereas the acute hoof angulation was approximately 10 degrees lower than the normal angle for the individual horse. The acute angle was achieved by allowing the toes to grow relatively longer than the heels. The results of a multivariate analysis of variance showed significant differences between the two farriery treatments in t...
Diaphragmatic perfusion heterogeneity during exercise with inspiratory resistive breathing. Regional distribution of diaphragmatic blood flow (Q; 15-microns-diam radionuclide-labeled microspheres) was studied in normal (n = 7) and laryngeal hemiplegic (LH; n = 7) ponies to determine whether the added stress of inspiratory resistive breathing during maximal exercise may cause 1) redistribution of diaphragmatic Q and 2) crural diaphragmatic Q to exceed that in maximally exercising normal ponies. LH-induced augmentation of already high exertional work of breathing resulted in diminished locomotor exercise capacity so that maximal exercise in LH ponies occurred at 25 km/h compared with 3...
Synchronization of locomotion and respiration in trotting ponies. The aim of the present experiment was to investigate the hypothesis that there is a respiration-locomotion coupling in trotting equines. Therefore the respiratory airflow (V), the gastric pressure (Pga) and pleural pressure (Ppl) changes and the step frequency (SF) were simultaneously recorded in 5 trotting ponies (body weight: 255 +/- 15 kg; age: 3.5 +/- 0.4 years). Airflow was measured using a Fleisch pneumotachograph fixed on a face mask. Esophageal and gastric balloon catheters coupled to pressure transducers allowed the recording of Ppl and Pga. The exercise was performed on a treadmill a...
Correction for skin displacement errors in movement analysis of the horse. In movement analysis of the horse, large errors result from movements of the skin with respect to the underlying bones. A generally applicable, two-dimensional, method for correction of these skin-movement errors in kinematic data has been developed. It was tested on a kinematic analysis of the hindlimb in a walking pony. The results indicate that without correction for skin-movement errors, misreadings of up to 15 degrees in the knee angle and 30% in the moment arm of the gastrocnemius muscle can be expected.
Application of a Hall-effect transducer for measurement of tendon strains in horses. Custom-designed Hall-effect strain sensors (HES) were implanted surgically onto the superficial digital flexor tendons of the forelimbs of 4 adult Thoroughbreds. Strains were recorded at various gaits, using a portable amplifer and FM cassette recorder. Strain calculations used the original length (L) as the HES position with the forelimb in the relaxed neutral position during anesthesia. A characteristic deflection in the strain cycle recording was confirmed to correspond to initial hoof contact with the ground (heel strike) by simultaneous recording of weight bearing via a footswitch. Heel s...
Electromyographic activity of cubital joint muscles in horses during locomotion. Electromyographic (EMG) activity of 4 muscles of the cubital joint and the strain of forelimb hooves were recorded telemetrically in 4 Thoroughbreds (with and without a rider) standing, walking, trotting, and cantering. Bipolar fine wire electrodes were inserted into the muscles, and strain gauges were attached to the hoof wall. Motion pictures (16 mm), synchronized with EMG tracings, were taken to obtain kinematic data. When horses were standing, the biceps brachii had tonic activity, but the brachialis and the caput longum and the caput laterale of the triceps brachii had no EMG activity. Th...
Pharmacologic effects and detection methods of methylated analogs of fentanyl in horses. Pharmacologic effects of alpha-methylfentanyl and 3-methylfentanyl, analogs of fentanyl, were investigated in mares. The ability of an 125I-labeled fentanyl radioimmunoassay (125I-RIA) to detect these methylated fentanyl analogs in individual and pooled urine samples from horses was evaluated. Also, the ability of 7 fentanyl antibodies to react with fentanyl and fentanyl derivatives (sufentanil, alfentanil, and carfentanil) was investigated. Mares were studied in a locomotor test to determine the amount of stimulation methylated fentanyl analogs might induce. Two mares each were given alpha-me...
Narcotic analgesics, their detection and pain measurement in the horse: a review. Narcotic analgesics produce pharmacological effects by interacting with specific opiate receptors. At least five major types of opiate receptors have been recognised. These include mu (morphine) and kappa (ethylketazocine) receptor types. Narcotic analgesics which interact with mu receptors produce locomotor and autonomic stimulation at doses that produce little or no analgesia. Therefore, use of these drugs as analgesics in equine medicine has not been very satisfactory. Theoretical considerations suggested that the role of kappa agonists in equine analgesia be investigated. Using a pure kapp...
Simulation of quadrupedal locomotion using a rigid body model. Locomotion of the horse is simulated using a mathematical model based on rigid body dynamics. A general method to generate the equations of motion for a two-dimensional rigid body model with an arbitrary number of hinge joints is presented and a numerical solution method, restricted to tree-structured models, is described. Joint movements originating from muscular forces or moments are simulated, but the method also allows that parts of the model follow strictly the pattern of kinematic data. Moment-generators with first-order linear feedback were used as a rotational muscle-equivalent. Ground...
Instant centres of rotation of equine limb joints and their relationship to standard skin marker locations. The instant centres of rotation (ICRs) of each limb joint, other than the coxofemoral joint and those of the digits, were calculated for eight clinically sound horses from tracings of radiographs according to the method of Reuleaux (1963). The majority of ICR positions coincided with the attachment sites of the collateral ligaments. The ICR of the scapulohumeral joint, which does not have collateral ligaments, was caudodistal to the caudal part of the greater tubercle of the humerus. The ICR for the femorotibial joint was located just caudal to the femoral attachment of the collateral ligament...
Speed, stride frequency and energy cost per stride: how do they change with body size and gait? In this study we investigate how speed and stride frequency change with body size. We use this information to define 'equivalent speeds' for animals of different size and to explore the factors underlying the six-fold difference in mass-specific energy cost of locomotion between mouse- and horse-sized animals at these speeds. Speeds and stride frequencies within a trot and a gallop were measured on a treadmill in 16 species of wild and domestic quadrupeds, ranging in body size from 30 g mice to 200 kg horses. We found that the minimum, preferred and maximum sustained speeds within a trot and a...
The gait of pacers. 2: factors influencing pacing speed. Standardbred pacers were studied at four different nominated speeds and selected gait kinematics were analysed to determine factors which contribute to pacing speed. A deterministic model is proposed in which pacing speed is a function of stride length and stride timing variables. Stance length and suspension time remained relatively constant over the different pacing speeds. Variables which discriminated best between pacing speeds were suspension length and overlap time. At near maximal speed, the pacers increased speeds with increased stride length. This was attributed to an increased suspen...
Evaluation of equine locomotion during different degrees of experimentally induced lameness. II: Distribution of ground reaction force patterns of the concurrently loaded limbs. Force plate and high-speed film data from a group of six walking horses were used to study the distribution of the ground reaction forces (GRF) of the concurrently loaded limbs. Three different degrees of supporting lameness were induced in a forelimb or a hindlimb using modified horse shoes. In all experiments the alterations in the distribution in the transverse horizontal GRF (Fx) were small. During unilateral forelimb lameness, the decreased longitudinal horizontal GRF (Fy) was compensated by an increase of the Fy forces of the contralateral forelimb and the ipsilateral hindlimb. The decre...
The gait of pacers. 1: kinematics of the racing stride. Standardbred pacers have been studied under race conditions to describe the gait of the pacer, and to determine relationships between stage of the race, finish order and selected gait kinematics. Overlap increased with the stage of the race while pacing speed decreased marginally for low order pacers and increased for high order finishers. High order finishing pacers appear to have greater stance and stride lengths than do low order finishers. Pacers could be separated into low order and high order groups on the basis of their movement patterns. High order pacers exhibited greater ranges of li...
Evaluation of equine locomotion during different degrees of experimentally induced lameness. I: Lameness model and quantification of ground reaction force patterns of the limbs. Force plate data from walking horses were used to evaluate the locomotion of a group of six horses during experimentally induced lameness in a forelimb or a hindlimb. By tightening or loosening screws in modified horseshoes the resulting pressure pain on the sole enabled induction and release of three different degrees of supporting lameness within a period of 2 h. The ground reaction force (GRF) patterns of the different recording sessions were compared with control data of the same horse as well as with the 'standard' horse data using a quantitative evaluation procedure involving 93 GRF para...
Effect of exercise on the partitioning of equine respiratory resistance. Pleural, tracheal, pharyngeal and mask pressures as well as airflow and tidal volume of five ponies on a treadmill (incline 8.3 degrees) were recorded simultaneously while resting, walking, trotting slowly, trotting fast, after standing for 30 secs and 5 mins after the end of the exercise. The curves obtained were used to calculate total pulmonary resistance (RL), lower airway resistance (RLA) and upper airway resistance (RUA). The latter was also divided into nasal resistance (Rnas) and laryngeal plus extrathoracic tracheal resistance (Retr + lar). Furthermore, the inspiratory and expiratory ...
Distribution of ground reaction forces of the concurrently loaded limbs of the Dutch Warmblood horse at the normal walk. The distribution of the ground reaction forces (GRF) over the concurrently loaded limbs of the normally walking horse was determined from 'representative' GRF patterns of all limbs, which were plotted in correct time order after analysis of simultaneously taken high-speed film. This procedure visualises the GRF patterns of each of the four limbs in relation to the GRF pattern(s) of the one or two concurrently loaded limb(s) during a complete stride. In 15 clinically sound horses the mean averaged GRF data and temporal stride parameters showed an almost complete symmetry between both the foreli...
Dose related effects of the kappa agonist U-50, 488H on behaviour, nociception and autonomic response in the horse. Current opiate receptor theory suggests that kappa agonists should provide good analgesia without producing marked central nervous system stimulation. U-50,488H is an experimental narcotic analgesic that is a selective kappa agonist. In the present study, U-50,488H produced good analgesia in horses using both the skin twitch and hoof withdrawal reflex assays. Further, the analgesia was relatively long lasting (120 mins) compared to other mu-agonists tested in horses. The locomotor response to U-50,488H was less than observed with ethylketazocine and butorphanol, and has yielded the smallest lo...
Platelet activating factor as a mediator of equine cell locomotion. Equine polymorphonuclear (PMN) and mononuclear (MN) leucocytes were separated on Percoll gradients and used to study the chemoattractant properties of the polar ether-linked phospholipid, platelet activating factor (PAF). Six concentrations of PAF ranging from 1 ng/ml to 100 micrograms/ml were studied in each of two in vitro assay systems, the agarose microdroplet and a microfilter technique. Very significant (p less than 0.01) increases in the movement of both PMN and MN cells were obtained with most concentrations of PAF. In two instances there was no apparent concentration-response relation...
Pulmonary mechanics during treadmill exercise in race ponies. Exercise-induced variations in their ventilatory mechanics were studied in 8 healthy ponies 4.2 +/- 1.4 years old and weighing 282 +/- 11 kg. Airflow (V), tidal volume (VT), esophageal pressure, mask pressure and electrocardiogram were simultaneously recorded before, during and after a treadmill (incline 8.3 degrees) exercise which consisted of 2 min walking (1.5 m.sec-1), 3 min slow trotting (3.0 m.sec-1) and 3 min fast trotting (3.5 m.sec-1). The results of three consecutive daily measurements were averaged for each pony. Heart rate, minute volume (Ve), respiratory frequency (f) and peak ins...
Influence of chemotactic agents on the locomotion of equine polymorphonuclear and mononuclear leucocytes. Subpopulations of equine leucocytes, polymorphonuclear and mononuclear cells, were separated from whole blood on a discontinuous Percoll gradient and used in studies of chemokinesis and chemotaxis. Polymorphonuclear cells responded to the chemo-attractant properties of zymosan-activated plasma in Boyden chamber and agarose microdroplet assays but they responded only slightly (Boyden chamber) or not at all (agarose microdroplet) to the peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP). Equine mononuclear cell movement was increased by FMLP in both assay systems and these cells also respond...
Effect of povidone-iodine on in vitro locomotion of equine neutrophils. Incubation of equine neutrophils with povidone-iodine solutions of greater than or equal to 0.2 per cent resulted in total inhibition of migration under agarose. This was caused by the cytotoxic effects of the solutions as shown by pyknosis and cell lysis. Lower concentrations of povidone-iodine, however, did not adversely affect neutrophil viability or locomotion.
Early development of gait asymmetries in trotting standardbred colts. Ten trotting Standardbred colts were recorded by high-speed cinematography at the ages of eight, 12 and 18 months. The horses were trotting on a treadmill operating at 4.0 m/secs. Five horses were subjected to a programme of intensified training from eight months of age, whereas the others were not trained and acted as controls. The films were analysed on a semi-automatic film-reading equipment and a number of variables used to demonstrate the gait symmetry were calculated and scaled by computer. Certain differences between left and right diagonal and contralateral pair of limbs, respectively,...
Identification of hindleg lameness. The use of markers placed over the tuber coxae on each side of a horse to aid identification of the relative movement of these structures at the trot, for teaching and research purposes, is described. In each case of hindleg lameness studied, the tuber coxae on the lame side showed a consistent increase in vertical displacement relative to that of the contralateral limb, and a characteristic pattern of movement throughout the stride irrespective of the site or cause of pain.
Multivariate statistical analysis of stride-timing measurements of nonfatigued racing Thoroughbreds. Standard univariate and bivariate statistical methods and two multivariate methods, stepwise regression and factor analyses, were used to analyze 17 stride-timing measurements of 22 racing Thoroughbreds filmed at the beginning of races. All horses were in a right-lead transverse gallop. Data were extracted from frame-by-frame analysis of 16-mm film taken with a high-speed camera. The mean stride duration was 0.405 s and the mean stride frequency was 2.47 strides/s. Stride duration had a higher correlation to the suspension-phase duration (r = 0.864) than to stride-stance-phase duration (r = 0....
