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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.
Forelimb kinematics and net joint moments during the swing phase of the trot. The purpose of this study was to calculate net moments of force at the joints of the forelimb during the swing phase of the stride. An optoelectronic system was used to measure segmental kinematics for 3 strides in 5 sound, Warmblood horses trotting at a mean velocity +/- s.d. of 3.03 +/- 0.16 m/s. A link segment model was used to determine the net moments of force about the joints of the left forelimb. The model combined kinematic data with morphometric data describing the inertial parameters of the limb segments of warmblood horses, and incorporated correction factors for skin displacement. ...
A comparison between the trot of pony and horse foals to characterize equine locomotion at young age. The trot at 3 m/s of 24 Shetland foals ('ponies') and 24 Dutch Warmblood foals ('horses') was recorded at age 4 months on a treadmill using a modified CODA-3 apparatus to characterise equine locomotion at young age. Locomotor variables of the ponies were qualitatively and, after scaling, quantitatively compared with those of horses. Ponies made shorter strides than horses, evidenced by a shorter stance and swing duration, although their relative stance durations were similar. Neither linear nor dynamic scaling procedures could completely compensate for differences in height at the withers comp...
The effect of training on the calcified zone of equine middle carpal articular cartilage. Carpal osteochondral injury is frequently observed in strenuously trained horses. It is clear that the integrity of articular cartilage and subchondral bone are intimately related, although there is controversy about which component is the most important. Calcified cartilage provides the mechanical link between soft hyaline cartilage and stiff subchondral bone so it is essential to understand the tissue's response to exercise. Middle carpal calcified and uncalcified (hyaline) cartilage thickness was investigated in horses undergoing high- and low-intensity exercise. Twelve untrained horses (18...
Temporal changes in the trot between the first and third horse inspections at a CCI*** 3-day event. Kinematic parameters were measured from horses competing in a CCI*** 3-day event. The horses were filmed during the first and third horse inspection. This provided a repeat sample on 16 horses. The horses were filmed using a panning lateral S-VHS video camera (50 Hz). Spatial measurements were taken for mean +/- s.d. 5.66 +/- 0.92 strides for the first inspection and 5.05 +/- 1.27 for the third inspection. Within the calibration zone, data of the horses accelerating and obtaining a constant velocity were collected. The horses trotted with a higher mean velocity during the third inspection (0.2...
Nerve block and intra-articular anaesthesia of the forelimb in the sound horse. Nerve blocks and intra-articular anaesthesia are used extensively as routine methods in lameness evaluation. The method is based on the assumption that the technique itself does not change the movement pattern. The aim of this study was to carry out a quantitative kinematic study to confirm or reject the hypothesis that high palmar digital nerve block (HPDN) and intra-articular fetlock joint anaesthesia (IAF) influence significantly the movement pattern of the horse. Seven Standardbred horses trotting at 4.5 m/s were recorded at 240 Hz on a treadmill before and after anaesthesia by use of a Pr...
Comparison of exercise tests in French trotters under training track, racetrack and treadmill conditions. Standardised exercise tests were performed at 2 different tracks and on an uninclined treadmill during the same week to determine the influence of exercise surface on different measured variables such as heart rate (HR), blood lactate concentration, packed cell volume, stride frequency, stride length, gait symmetry and regularity and on different derived physiological variables such as the speed at a HR of 200 beats/min (V200), the speed at a blood lactate concentration of 4 mmol/l (V4), the speed at a maximal HR (VHRmax). Five French Trotters, age 3 years, in training for 3 months prior to th...
In vitro transmission and attenuation of impact vibrations in the distal forelimb. An in vitro model was developed and validated in vivo to quantify the attenuation of impact vibrations, transmitted through the lower equine forelimb and to assess the effects of horseshoeing on this attenuation. The transsected forelimbs of 13 horses were equipped with custom-made hollow bone screws in the 4 distal bones, on each of which a tri-axial accelerometer could be mounted. The limbs were then preloaded while the impact was simulated by dropping a weight on the steel plate on which the hoof was resting. At the hoof wall, the distal, middle and proximal phalanx and at the metacarpal bo...
Influence of rough track surfaces on components of vertical forces in cantering thoroughbred horses. No kinetic data are available to indicate the influence of a rough track surface and the resultant loss of footing on the components of hoof vertical forces. The aim of the present study was to evaluate the influence of rough track surfaces on the components of hoof vertical forces. Seven clinically sound 2-year-old Thoroughbred horses had instrumented shoes attached to both of the fore hooves to obtain the magnitudes of consecutive forces exerted in the hoof. All horses were cantered at approximately 10 m/s on straight tracks of smooth and rough surfaces of woodchip and dirt. The instrumented...
Thermoregulatory strategies during short-term exercise at different intensities. Previously we have observed a decline in sweating rate (SR) during high intensity exercise in an incremental test protocol. In man, the sweating sensitivity (SR/degree C) has been shown to vary with exercise intensity. The aim of the present study was to determine if thermoregulatory responses in the horse, a prolific sweater with a high rate of metabolic heat production, were modified by exercise intensity. The effect of 3 separate exercise intensities (50 (S), 70 (M) and 90% (F) VO2peak on neck (SRN) and gluteal sweating rate (SRG), pulmonary artery (TPA), rectal (TREC) and skin temperatures...
Modelling impact-initiated wave transmission through lung parenchyma in relation to the aetiology of exercise-induced pulmonary haemorrhage. Recently we proposed that exercise-induced pulmonary haemorrhage (EIPH) results from locomotory-impact-induced trauma by impact of the scapula on the chest wall during footfall and the consequent transmission of waves through the lung. A computational model has been developed to demonstrate that wave amplification and focusing occur in the dorsocaudal tip of the lung for waves originating on the anterior subscapular surface. The propagation of an acoustic wave was investigated in a simplified 2-dimensional representation of a vertical anterio-dorsal section of horse lung. It was demonstrated t...
EMG activity of the muscles of the neck and forelimbs during different forms of locomotion. We recorded the electromyographic (EMG) activity of 7 skeletal muscles in the forequarters and 1 in the hindquarters of 6 Thoroughbred horses during overground walking, swimming in a circular pool, and walking and trotting in a water treadmill. Bipolar fine wire electrodes were inserted into the muscles and the EMG signals were recorded using a telemetric system. The splenius exhibited tonic EMG activity during swimming. The brachiocephalicus showed its highest intensity during swimming followed by the walk and trot in the water treadmill and then walking overground. The triceps brachii caput ...
The kinematics of loading and fatigue in the standardbred trotter. The Standardbred trotter must pull a considerable load when racing and, consequently, draught loading is a common method of training in the Standardbred and the effects of loading and fatigue due to loading on the locomotor pattern was the purpose of this investigation. Four mature healthy Standardbred horses trotted with and without a horizontal-pulling loading of 34 kg until the horses were no longer willing to keep pace with the treadmill despite encouragement. Heart rate was monitored every min using a bipolar electrocardiogram. The kinematics for 5 consecutive strides were filmed. Horses ...
An in vitro biomechanical investigation of an equine interlocking nail. To determine the mechanical properties of Equine Interlocking Nail (EIN; JD Wheat Veterinary Orthopedic Research Laboratory, University of California, Davis) stabilized osteotomized tibiae and compare these variables with estimated in vivo loads. Methods: In vitro biomechanical investigation. Methods: Twelve adult equine cadaveric tibiae. Methods: EIN-stabilized tibiae were tested monotonically under compression, 3- and 4-point bending, and torsion. Mechanical properties were compared with estimated in vivo loads. Results: EIN-tibial composite mean compressive yield load (11 kN) and bending mo...
Time of contact and step length: the effect of limb length, running speed, load carrying and incline. Using published values for twelve species of birds and mammals, we investigated the effects of limb length and running speed on time of contact and step length. In addition, we measured the time of contact in horses trotting up a 10 % incline and when carrying a load averaging 19 % of their body mass. From these values, we calculated stride period and step length. Our analysis of the interspecific data yielded the following relationship between time of contact (t(c) in s) and leg length (L in m) and running speed (v in m s(-)(1)): t(c)=0.80L(0.84)/v(0.87) (r(2)=0.97). Both exponents in this re...
In vitro mechanical properties of different equine hoof wall crack fixation techniques. Hoof wall cracks need mechanical stabilisation to allow healing. Common techniques are fixation with screws, wires and plates or bonding of a patch across the crack. An in vitro system to determine the shear properties of equine hoof crack repairs is described. The force and displacement at yield, stiffness and ultimate force were determined for 4 repair techniques based on an acrylic material, polyurethane patch attached with cyanoacrylate adhesive, steel plate attached with screws and a transverse metal bar cut into the hoof wall. The cyanoacrylate bonded patch repair had lower values for al...
Exercise affects the mechanical properties and histological appearance of equine articular cartilage. Dorsal carpal osteochondral injury is a major cause of reduced performance in horses undergoing high-intensity training. It was hypothesised that the mechanical behaviour and histology of cartilage are influenced by the intensity of exercise and by location within a joint. Relationships between histology and mechanical behaviour were identified in 2-year-old horses undergoing 19 weeks of high-intensity treadmill training or low-intensity exercise and then compared between groups. Dorsal and palmar test sites were identified on radial, intermediate, and third carpal articular surfaces after eut...
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 ...
Supporting forelimb lameness: clinical judgement vs. computerised symmetry measurement. The aim of this study was to compare supporting forelimb lameness determined by a motion analysis system with the subjective grading of a trained equine orthopaedic surgeon. Trotting on a treadmill, 29 individuals with a supporting forelimb lameness were measured with the SELSPOT II system and judged by the clinician. The vertical motion of the head was measured, analysed using Fourier transform, and the percentages of symmetry determined. The veterinarian evaluated the lameness and graded it according to a clinical routine. Veterinarian and system for motion analysis assigned the lameness to ...
Influence of artificial saddle riding on postural stability in children with cerebral palsy. Stability of quiet upright stance was investigated in 25 children with cerebral palsy at the beginning and the end of a 3-month period of therapy involving 20 min microprocessor-controlled saddle riding, performed twice a week. The traditional parameters of postural sway based on the centre-of-pressure analysis (range, standard deviation, mean speed and mean radius) dropped significantly over time confirming advantageous influence of this treatment. As a complementary tool, an autoregressive modelling technique was used allowing us to establish after each single ride considerable decreases in ...
An in vitro biomechanical comparison of an interlocking nail system and dynamic compression plate fixation of ostectomized equine third metacarpal bones. To compare the mechanical properties of two stabilization methods for ostectomized equine third metacarpi (MC3): (1) an interlocking nail system and (2) two dynamic compression plates. Animal or Sample Population-Ten pairs of adult equine forelimbs intact from the midradius distally. Methods: Ten pairs of equine MC3 were divided into two test groups (five pairs each): caudocranial four-point bending and torsion. Interlocking nails (6 hole, 13-mm diameter, 230-mm length) were placed in one randomly selected bone from each pair. Two dynamic compression plates one dorsally (12 hole, 4.5-mm broad)...
An in vitro biomechanical comparison of two fixation methods for transverse osteotomies of the medial proximal forelimb sesamoid bones in horses. This study compared the mechanical properties of the normal intact suspensory apparatus and two methods of fixation for repair of transverse, midbody fractures of the proximal sesamoid bones of adult horses: transfixation wiring (TW) and screws placed in lag fashion (LS). Methods: An in vitro, paired study using equine cadaver limbs mounted in a loading apparatus was used to test the mechanical properties of TW and LS. Methods: Seventeen paired (13 repaired, 4 normal) equine cadaver limbs consisting of the suspensory apparatus third metacarpal bone, and first and second phalanges. Methods: The...
Validity of saddle pressure measurements using force-sensing array technology–preliminary studies. Back pain is a common and poorly understood clinical problem. An important factor in this regard is the induction or exacerbation of back pain from badly designed or poorly fitting saddles. This study used a pressure-sensing mat to investigate saddle fit. The aims of the study were to confirm the accuracy and reliability of the force-sensing array technology when used to measure pressure beneath the saddles of horses, and to collect some initial data from normal healthy horses with well-fitting saddles. Experiments were undertaken to establish that a linear relationship existed between the tot...
Influence of intermittent pressure, fluid flow, and mixing on the regenerative properties of articular chondrocytes. Equine articular chondrocytes, embedded within a polyglycolic acid nonwoven mesh, were cultured with various combinations of intermittent pressure, fluid flow, and mixing to examine the effects of different physical stimuli on neochondrogenesis from young cells. The cell/polymer constructs were cultured first in 125 ml spinner flasks for 1, 2, or 4 weeks and then in a perfusion system with intermittent pressure for a total of up to 6 weeks. Additional constructs were either cultured for all 6 weeks in the spinner flasks or for 1 week in spinners followed by 5 weeks in the perfusion system with...
Limb locomotion–speed distribution analysis as a new method for stance phase detection. The stance phase is used for the determination of many parameters in motion analysis. In this technical note the authors present a new kinematical method for determination of stance phase. From the high-speed video data, the speed distribution of the horizontal motion of the distal limb is calculated. The speed with the maximum occurrence within the motion cycle defines the stance phase, and this speed is used as threshold for beginning and end of the stance phase. In seven horses the results obtained with the presented method were compared to synchronous stance phase determination using a for...
The mechanisms and consequences of structural failure of the foot. Many of the difficulties in managing the horse with chronic laminitis are associated with the foot's mechanical failure. The occurrence of digital collapse cannot be viewed in isolation as the primary therapeutic focus. The circulatory, metabolic, and growth pattern changes induced by the foot's mechanical collapse often serve as major limiting factors to successful rehabilitation. From the discussion above, it is obvious that a significant amount of research is needed to better understand the biomechanical pathologies of the failed foot.
Effect of feed rate and drill speed on temperatures in equine cortical bone. To examine the amount of heat generated in equine cortical bone by a 6.2-mm drill, using low- and high-speed and controlled feed rate drilling. Methods: 10 metacarpal bones harvested from five 2-year-old draft-type horses. Methods: Drilling on metacarpal bones was done using a machine shop mill with which the feed rate and drill speed could be precisely controlled. Bones were drilled, using 6 combinations of feed rate (1, 2, and 3 mm advance/s) and drill speed (317 and 1,242 revolutions/min [rpm], with maximal temperatures recorded by thermocouples placed 1, 1.5, and 2 mm from the drill. Maxim...
The relationship between mechanical work and energy expenditure of locomotion in horses. Three-dimensional motion capture and metabolic assessment were performed on four standardbred horses while walking, trotting and galloping on a motorized treadmill at different speeds. The mechanical work was partitioned into the internal work (W(INT)), due to the speed changes of body segments with respect to the body centre of mass, and the external work (W(EXT)), due to the position and speed changes of the body centre of mass with respect to the environment. The estimated total mechanical work (W(TOT)=W(INT)+W(EXT)) increased with speed, while metabolic work (C) remained rather constant. A...
A method for determination of equine hoof strain patterns using photoelasticity: an in vitro study. During impact, equine hooves undergo viscoelastic deformations which may result in potentially harmful strains. Previous hoof strain studies using strain gauges have been inconclusive due to arbitrary gauge placement. Photoelastic stress analysis (PSA) is a full-field technique which visually displays strains over entire loaded surfaces. This in vitro study identifies normal hoof strain patterns using PSA. Custom-made photoelastic plastic sheets were applied to the hoof surface. The hooves were axially loaded (225 kg) under level and varus/valgus conditions. Strain patterns were video-recorded...
[Effect of common head gear on horses]. The functions of the most common head-gears for horses are analysed from a biomechanical point of view. With the exception of the stable halter are all of them designed to enlarge the tensile forces transmitted through the reins or the longe, and to concentrate the enlarged forces on sensitive parts of the horse's head: the nose, or the lips, mandible and tongue. Since the direction, duration and size of these tensile forces are the essential factors to modulate signals for controlling the horse, a device has been developed to measure, or at least roughly quantify these forces. The mechanical ...
