Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Biomechanics
Biomechanics in horses refers to the study of the mechanical principles that govern movement and physical function in equine species. This field encompasses the analysis of gait, locomotion, and the forces exerted by and upon the horse's musculoskeletal system. Biomechanical studies often involve the use of motion capture technology, force plates, and computer modeling to assess how horses move and how various factors, such as conformation, training, and health status, influence their performance and soundness. Research in equine biomechanics contributes to understanding injury prevention, rehabilitation, and performance optimization. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanics of movement, the impact of external and internal forces, and the applications of biomechanical analysis in equine care and management.
Ground reaction force patterns of Dutch warmblood horses at normal trot. This study was undertaken to establish limb loading patterns of sound horses at the trot, to provide a data base against which results for lame horses could be compared. Ground reaction force (GRF) data were collected from 20 clinically sound Dutch Warmblood horses. The data from at least 5 stance phases of each limb were averaged after standardisation to the animal's body mass and to the stance phase duration and resulted in 'representative' GRF data. The symmetry in the vertical GRF peak amplitudes, impulses and the stance phase duration comparing left and right limbs exceeded 97%. By averag...
Mechanical implications of collagen fibre orientation in cortical bone of the equine radius. Mechanical test specimens were prepared from the cranial and caudal cortices of radii from eight horses. These were subjected to destructive tests in either tension or compression. The ultimate stress, elastic modulus and energy absorbed to failure were calculated in either mode of loading. Analysis was performed on the specimens following mechanical testing to determine their density, mineral content, mineral density distribution and histological type. A novel technique was applied to sections from each specimen to quantify the predominant collagen fibre orientation of the bone near the plane...
Multi-body modelling and simulation of animal locomotion. 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...
Shortening of the forelimb in the horse during the stance phase. Compressions in the forelimb of a horse trotting at 3.7 m/s were studied using high-speed cinematography. From a diagram of shortenings it has been concluded that successive loadings in the longitudinal direction from below signify longer impact time and smaller impact forces compared to a theoretically stiff limb. It is proposed that the limb takes up the impact force passively until the onset of loading at the elbow joint, i.e. 30 ms following first contact.
Recommended terminology for researchers in locomotion and biomechanics of quadrupedal animals. This paper summarizes recommendations for terminology to be used in the description of quadrupedal locomotion and selected aspects of biomechanics. Directional terms and planes of the body (anatomical position, spatial reference systems), joint angulation, conformation, general locomotion terminology, phases of the stride and limb cycle (e.g. step, cadence) and terminology for the description of jumping are described.
Relationship between locomotor forces, hoof position and joint motion during the support phase of the stride of galloping horses. Three methods were used simultaneously to determine the relationships between the vertical forces exerted on the hooves and the positions of the limbs and hooves at the times of peak vertical forces from 2 horses galloping on a track straightaway. Vertical forces were recorded from an instrumented shoe, fetlock joint motion was measured with an electrogoniometer and the angles of the carpus, fetlock and hoof were determined from slow-motion films. At hoof contact, the mean angles of the carpus and fetlock were 181-182 degrees and 199-206 degrees, respectively. Peak vertical forces on the heel ...
Surface strain on the dorsal metacarpus of thoroughbreds at different speeds and gaits. Stacked rectangular rosette strain gages were used to measure surface bone strain on the dorsomedial cortex of the third metacarpal bones in 6 adult Thoroughbred horses during treadmill exercise. The peak principal compressive and tensile strains, angle of the peak strains and strain rate during loading were calculated and compared with speed and gait. At speeds from 4 to 14 m/s loading on the metacarpus resulted in compression of the dorsomedial cortex. Tension only occurred consistently in 1 forelimb of 1 horse at the walk (2 m/s). The angle of peak compression was within 10 degrees of the l...
Determination of the center of pressure of the hoofs of the forelimbs of horses standing on a flat level surface. The pressure exerted on a flat level surface by recently trimmed, unshod hoofs of the front limbs of 23 sound, adult horses was measured using pressure-sensitive film and a specially built cassette. The horses were tranquilized and stood with one foot on the 2.9-cm-thick cassette and the other on a block of equal height. The hoofs were observed for motion during the measurement, and the developed film was examined for improper alignment of the film or slipping of the hoof. The center of pressure was located using the method of weighted proportions of Barrey. This static measurement system with...
In vivo tendon forces in the forelimb of ponies at the walk, validated by ground reaction force measurements. The load distribution over tendinous structures in the equine forelimb was studied by computing forces from in vivo signals of implanted liquid-metal strain gauges in 5 ponies. For validation, these tendon forces were converted to joint moments, which were summed and compared to the calculated joint moments caused by the ground reaction force. Mean peak forces per kilogram body weight (n = 5) amounted to 5.2 N/kg for the superficial digital flexor tendon, 3.8 N/kg for the deep digital flexor tendon, 7.3 N/kg for the distal accessory (check) ligament and 8.4 N/kg for the third interosseous musc...
Comparison of the damping effect of different shoeing by the measurement of hoof acceleration. 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...
Kinematic gait analysis in equine carpal lameness. 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 ...
The extended canter: a comparison of some kinematic variables in horses trained for dressage and for racing. This study was designed to test the hypothesis that there is no significant difference in selected temporal and linear stride variables of the extended canter in horses bred and trained for dressage or racing. Nine advanced-level dressage horses and 7 Thoroughbred racehorses were filmed at a frame rate of 200 Hz at an extended canter on a sand track. Two strides were recorded per trial, and each horse performed 6 or 7 trials. Temporal and linear data were determined from the films, and descriptive statistics (mean, SD) were calculated. Strides were selected for analysis on the basis of having ...
A preliminary study of transitions between the walk and trot in dressage horses. The object of this study was to determine the limb support sequence during the transitions from walk to trot and from trot to walk in dressage horses under saddle and to test the null hypothesis that the limb support sequence during the transitions is not related to the level of training. Sixteen dressage horses training at novice to FEI Grand Prix level were videotaped performing an average of 9 transitions each from walk to trot and from trot to walk. The 30-Hz videotapes were viewed in slow motion, and based on the limb support sequence the transitions were categorized into two types. In ty...
Kinematics of the standardbred trotter measured at 6, 7, 8 and 9 m/s on a treadmill, before and after 5 months of prerace training. A kinematic study was performed on a group of 8 Standardbred stallions. Recordings were done using a modified CODA-3 optoelectronic kinematic analysis system with the horses running on a treadmill at speeds of 6, 7, 8, or 9 m/s. Linear and temporal gait characteristics, joint angle diagrams and the trajectories of the hoof in a plane perpendicular to the direction of movement were studied. Two consecutive recording sessions were held at an age of 21-23 months, and a third was held 5 months later after an intensive training period. Joint angle diagrams appeared to show a similar pattern for all...
Quantification of the locomotion of Dutch Warmblood foals. To get an in-depth insight into the ontogeny of the equine locomotor apparatus, the locomotion of 28 Dutch Warmblood foals was recorded at the walk, trot and canter on a treadmill using a CODA-3 apparatus. A great similarity in joint angle-time diagrams was found, although considerable differences in kinematic gait parameters of individual foals could be detected. These results contribute to an objective comparison of the locomotor performance of foals.
Stride characteristics of overground versus treadmill locomotion in the saddle horse. 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 frequenci...
A method to estimate the initial length of equine tendons. 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.
Quantification of hind limb lameness in the horse. The three-dimensional optoelectronic locomotion analysis system SELSPOT II was used for kinematic studies of hind limb locomotion patterns. Two groups, 11 sound horses and 15 horses suffering from hind limb lameness, were examined at the trot. Both graphical and quantitative analyses were compared in sound and lame horses. The parameter hip acceleration quotient (HAQ), using the different peaks of vertical acceleration of one hip during one stride, proved to be a suitable value for quantitative analysis of hind limb lameness. In sound horses the HAQ ranged from 1.03 to 1.54, lame horses showed...
Gallop kinematics of Olympic three-day event horses. Limb contact variables of the gallop of 3-day event horses were determined for competitors in the 1988 Seoul Summer Olympic Games. Horses were filmed during the steeplechase, phase B of the speed and endurance test on day 2 of competition. Two 16-mm high-speed cameras were aimed perpendicularly to the direction of subject motion along a straightaway on the steeplechase track, filmed at 200 frames/s. Thirty-four of 48 competitors were filmed and 108 gallop strides analyzed. Velocity (VEL) averaged 12.09 +/- 0.10 m/s (mean +/- SE), stride length (SL) 6.04 +/- 0.05 m and stride frequency (SF) 2.0...
Strain of the musculus interosseus medius and its rami extensorii in the horse, deduced from in vivo kinematics. The in vivo strains of the musculus interosseus medius (suspensory ligament) and its rami extensorii (extensor branches) in the forelimb of the horse were determined from angular changes of the metacarpophalangeal and the distal interphalangeal joints. For this purpose, regression models were fitted to strains and joint angle combinations measured in in vitro limb loading experiments. The in vivo strains were computed from the kinematics of 8 horses at the walk, the trot and the canter. It was found that the extensor branches were strained about 1.0% at hoof impact, which indicates that they p...
Concept of a force-measuring horseshoe. 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 genera...
Effect of sodium hyaluronate in collagenase-induced superficial digital flexor tendinitis in horses. Superficial digital flexor tendinitis was induced in each forelimb of 8 horses by injecting 4,000 U of collagenase into the midmetacarpal region of the tendon. In each horse, each tendon was treated 24 and 96 hours after the collagenase injection with SC injections of sodium hyaluronate (treated limbs) or an equal volume of 0.9% NaCl solution (control limbs). Exercise was restricted for the first 3 weeks of the study, and a controlled exercise program was instituted for the remainder of the study. Horses were evaluated clinically for lameness, tendon swelling, and midmetacarpal limb circumfere...
Quantitative analysis of computer-averaged electromyographic profiles of intrinsic limb muscles in ponies at the walk. The function of several intrinsic muscles of the fore-and hind limbs of 5 ponies walking normally was evaluated via surface electromyography. Electromyographic signals were band-pass filtered, rectified, linear enveloped, and standardized to the stride duration. Mean data from the muscles of the left and right limbs that were obtained from at least 30 strides in 2 recording sessions were recorded as electromyographic signals-time curves. The timing of muscle activity was determined from these graphs. On the basis of the major peaks in the electromyographic signal, muscle functions were identif...
Measurement of tracheal static pressure in exercising horses. A nasotracheal catheter for measuring tracheal static pressure in exercising horses was designed according to aerodynamic engineering principles. Small ports near the end of the catheter transmitted pressure fluctuations to the recording apparatus. Accuracy was determined by the size, number, and location of pressure sensing holes on the catheter, and by the position of the catheter in the trachea. The catheter had adequate frequency response to 33 Hz, was insensitive to movement artifacts, was easily introduced, was tolerated well by horses, and resulted in small ventilatory impairment at max...
Functional significance of the morphology and micromechanics of collagen fibres in relation to partial rupture of the superficial digital flexor tendon in racehorses. The high incidence of partial rupture of the superficial digital flexor tendor in the equine athlete represents a major cause for concern in the racing industry. Frequently, the lesion is localised to the central core of the tendon. This study tested the hypothesis that the site specific structural failure results from differences in the collagen fibre morphology and associated micromechanics between central and peripheral regions of the tendon. Bundles of collagen fibres were dissected from central and peripheral sites in the mid-metacarpal region of the tendon. Crimp morphology was quantifie...
A kinematic and strain gauge study of the reciprocal apparatus in the equine hind limb. Hind limb kinematics were recorded in five horses at walk and trot using an opto-electronic CODA-3 system. Simultaneously, in vivo strain in the completely tendinous peroneus tertius muscle was registered by implanted mercury-in-silastic strain gauges. The origin-insertion length patterns of the peroneus tertius were calculated from raw kinematic data and from data corrected for the error caused by skin displacement, and compared with the directly measured strain. The strain patterns calculated from externally measured kinematic data appeared to be in accordance with the directly measured stra...
Holding power of cortical screws after power tapping and hand tapping. Paired equine third metacarpal bones were drilled and tapped for 4.5 mm and 5.5 mm cortical screws. Tapping was done by hand or with an air-driven reversible orthopedic drill. Screws were inserted and subjected to extraction forces to failure of the osseous threads or the screws. There was no difference in holding power of either screw size between hand-tapped and power-tapped holes.
Mechanical properties of suture materials in vitro and after in vivo implantation in horses. Tensile testing of reproducible loops of size 5 braided polyester, size 2 polyglycolic acid, size 2 monofilament nylon, and size 2 polydioxanone sutures was performed in vitro and after subcutaneous implantation in horses for 7, 14, and 28 days. Maximum breaking strength, energy absorption, and percentage elongation to breakage point were measured. Size 5 braided polyester had the highest maximum breaking strength and energy absorption over 28 days. Polydioxanone had better mechanical performance over 28 days than did polyglycolic acid. On day 28, none of these parameters was measurable in pol...
