Ground reaction forces (GRFs) in horses refer to the forces exerted by the ground on the horse's limbs during movement. These forces are integral to understanding equine locomotion, biomechanics, and limb health. GRFs are measured using force plates and are used to analyze gait patterns, assess lameness, and evaluate the effects of different surfaces or shoeing techniques on a horse's movement. Variations in GRFs can provide insights into the distribution of weight across the limbs and the mechanical loading experienced by the musculoskeletal system. This page compiles peer-reviewed research studies and scholarly articles that explore the measurement, analysis, and implications of ground reaction forces in equine locomotion and health.
Slavik K, Underwood C, Lowndes C, Skelton G, van Eps A.To examine the effects of botulinum toxin inoculation into the deep digital flexor (DDF) muscle on foot biomechanics. Unassigned: 6 healthy horses were injected with botulinum toxin in the DDF of 1 forelimb. The opposite forelimb was untreated. Ground reaction forces (GRF) were measured using a pressure sensor in regions of interest, including the dorsal hoof wall (toe). The location of the center of pressure (COP) was measured relative to the dorsal hoof wall during static standing and at peak stance during walking. Repeat measurements 3, 7, 14, 28, and 42 days after injection were compared t...
Aoun R, Ogunmola Z, Musso A, Taguchi T, Takawira C, Lopez MJ.The shift in vertical forces on the equine hoof surface by heart-bar, egg-bar, and wooden clog shoes can significantly impact gait kinetics. Hypotheses tested in this study were that vertical, braking, and propulsion peak force (PF) and impulse (IMP) are different while shod with heart-bar, egg-bar, open-heel, and wooden clog shoes, or while unshod, and the resultant ground reaction force vector (GRF YZ ) has the longest duration of cranial angulation with open-heel shoes followed by unshod, then egg-bar and heart-bar shoes, and the shortest with wooden clog shoes. Forelimb GRFs were recorded ...
Hobbs SJ, Tatlisulu A, Johnson A, Rowlands SD, Lucey M, Martin JH, Graydon RW, Northrop AJ.The maximum galloping speeds of racehorses during a race are influenced by the functional performance of the ground ('going') amongst other factors. For turf racecourses in Britain, the ground is descriptively classified and numerically quantified on the morning of a race meeting by the clerk of the course and subsequently published to assist decision making. Importantly, this includes deciding whether a horse should or should not run. The going is also assessed and classified during the meeting by racing analysts using the normalized winning times from each race result. Differences between go...
van Bijlert PA, Geijtenbeek T, Smit IH, Schulp AS, Bates KT.Musculoskeletal simulations can provide insights into the underlying mechanisms that govern animal locomotion. In this study, we describe the development of a new musculoskeletal model of the horse, and to our knowledge present the first fully muscle-driven, predictive simulations of equine locomotion. Our goal was to simulate a model that captures only the gross musculoskeletal structure of a horse, without specialized morphological features. We mostly present simulations acquired using feedforward control, without state feedback ("top-down control"). Without using kinematics or motion captur...
Gmel AI, Haraldsdóttir EH, Bragança FMS, Cruz AM, Weishaupt MA.Speed alterations affect many gait analysis parameters. How horses adapt to speed is relevant in many equestrian disciplines and may differ between breeds. This study described changes in gait parameters in 38 Warmblood (WB) and 24 Franches-Montagnes (FM) horses subjected to an incremental speed test at walk (1.35-2.05 m/s) and trot (3.25-5.5 m/s). Time, force and spatial parameters of each limb were measured with an instrumented treadmill and analysed with regression analysis using speed as the independent variable. With higher speeds, stride rate, length, over-tracking distance and vertica...
Reilly PT, van Eps A, Stefanovski D, Pfau T.Horseshoes with modified contact surfaces combined with deformable ground substrates are used to change hoof orientation during mid-stance, for example, for therapeutic reasons. Objective: To measure the effect of horseshoes and ground substrates on sagittal and transverse plane hoof orientation at mid-stance using a dorsal hoof wall mounted triaxial accelerometer. Methods: In vivo experiment, randomised crossover design. Methods: Differences in sagittal and transverse plane angles between standing and mid-stance of the left front hoof of six horses walking with regular horseshoes, egg bar, to...
Rohlf CM, Garcia TC, Marsh LJ, Acutt EV, le Jeune SS, Stover SM.During the stance phase of equine locomotion, ground reaction forces are exerted on the hoof, leading first to rapid deceleration ("braking") and later to acceleration ("propulsion") as the hoof leaves the ground. Excessive hoof deceleration has been identified as a risk factor for musculoskeletal injury and may be influenced by arena surface properties. Therefore, our objective was to evaluate the effect of arena surface type (dirt, synthetic) on hoof translation of the leading and trailing forelimbs during jump takeoff and landing. Solar hoof angle, displacement, velocity, and deceleration w...
Rohlf CM, Garcia TC, Fyhrie DP, le Jeune SS, Peterson ML, Stover SM.Mechanical properties of arena surfaces are extrinsic factors for musculoskeletal injury. Vertical impact forces of harrowed and compacted cushion were measured at five locations on 12 arena surfaces (five dirt, seven synthetic [dirt and fiber]). Eight variables related to impact force, displacement, and acceleration were calculated. Surface temperature, cushion depth and moisture content were also measured. The effects of surface material type (dirt/synthetic) and cushion compaction (harrowed/compacted) on vertical impact properties were assessed using an analysis of variance. Relationships o...
Parmentier JIM, Bosch S, van der Zwaag BJ, Weishaupt MA, Gmel AI, Havinga PJM, van Weeren PR, Braganca FMS.Vertical ground reaction force (GRFz) measurements are the best tool for assessing horses' weight-bearing lameness. However, collection of these data is often impractical for clinical use. This study evaluates GRFz predicted using data from body-mounted IMUs and long short-term memory recurrent neural networks (LSTM-RNN). Twenty-four clinically sound horses, equipped with IMUs on the upper-body (UB) and each limb, walked and trotted on a GRFz measuring treadmill (TiF). Both systems were time-synchronised. Data from randomly selected 16, 4, and 4 horses formed training, validation, and test dat...
Taguchi T, Morales Yniguez FJ, Takawira C, Andrews FM, Lopez MJ.Osteoarthritis (OA) accounts for up to 60% of equine lameness. Agmatine, a decarboxylated arginine, may be a viable option for OA management, based on reports of its analgesic properties. Six adult thoroughbred horses, with lameness attributable to thoracic limb OA, received either daily oral phenylbutazone (6.6 mg/kg), agmatine sulfate (25 mg/kg) or a control for 30 days, with 21-day washout periods between treatments. Subjective lameness, thoracic limb ground reaction forces (GRF), plasma agmatine and agmatine metabolite levels were evaluated using an established rubric, a force platform, an...
Rohlf CM, Garcia TC, Fyhrie DP, le Jeune SS, Peterson ML, Stover SM.Shear forces at the surface-hoof interface affect hoof slide, surface grip, forces transferred to the limb, and injury risk. However, the variation in shear forces among surfaces with different compositions have not been quantified. Shear ground reaction forces were measured on five dirt and seven synthetic arena surfaces. Cohesion/adhesion and angle of internal friction/coefficient of friction were calculated. Surface composition, surface temperature, cushion depth, and moisture content were also measured. The effects of surface material (dirt/synthetic) on shear properties were assessed usin...
Madsen LM, Gutierrez-Nibeyro SD, Stewart MC, McCoy AM, Schaeffer DJ.To determine the stance duration and ground reaction forces (GRF) of horses with deep digital flexor (DDF) tendinopathy at the level of the foot and compare the stance duration and GRF to those of clinically sound horses. Unassigned: Prospective clinical study. Unassigned: Sixteen horses (seven horses with bilateral forelimb lameness, four horses with unilateral forelimb lameness, and five horses with no lameness). Unassigned: Analyses of kinetic variables were performed on both forelimbs from sound horses and horses diagnosed with chronic DDF tendinopathy. Stance duration and longitudinal and...
King MR, Seabaugh KA, Frisbie DD.Back pain and inflammation of the epaxial musculature is a significant problem in all equine athletes. Treatment of back pain can be challenging and often requires a multimodal approach. In humans, bio-electromagnetic energy regulation therapy (BEMER) has been reported to be effective in pain modulation. With its increased use in people comes a similar robust application in veterinary medicine unfortunately, there is unsubstantiated evidence for this type of therapy in horses. Objectives of this study were to assess analgesic responses and biomechanical outcome variables using a bio-electromag...
Northrop AJ, Martin JH, Peterson ML, Roepstorff L, Hernlund E, Hobbs SJ.The design of equestrian arenas can be challenged by time constraints and specific restrictions at a venue but are nonetheless a critical element to the success and sustainability of equestrian sport. The equestrian arenas for the 2012 Olympic Games were an example of a temporary arena constructed on a raised platform and supported by struts, a design unprecedented for equestrian activities. This study assessed the developmental stages of the Olympic surfaces from 2011 to the actual event in 2012 and aimed to confirm that accelerations and forces experienced by horses were comparable to those ...
Akbari Shahkhosravi N, Gohari S, Komeili A, Burvill C, Davies H.Most simulation studies on equine hoof biomechanics employed linear elastic (LE) material models. However, the equine hoof wall's stress-strain relationship is nonlinear and varies with hydration level. Therefore, it is essential to investigate the accuracy of the LE model compared to more advanced material models, such as hyperelastic (HE) or viscoelastic models. The current research investigated performances of LE and three HE models (Mooney-Rivlin, Neo-Hookean, and Marlow) in describing equine hoof's mechanical behavior using finite element (FE) analysis. In the first attempt, a rectangular...
Wang P, Takawira C, Taguchi T, Niu X, Nazzal MD, Lopez MJ.To assess the effect of horseshoes with and without traction adaptations on the gait kinetics of nonlame horses during a trot on a concrete runway. Methods: 5 nonlame adult light-breed horses. Methods: Kinetic data were obtained for each horse when it was trotted across a force platform within a concrete runway unshod (control) and shod with standard horseshoes; standard horseshoes with high profile-low surface area calks, with low profile-high surface area calks, and coated with a thin layer of tungsten carbide (TLTC); and plastic-steel composite (PSC) horseshoes. Kinetic data were obtained f...
Clayton HM, Hobbs SJ.The piaffe is an artificial, diagonally coordinated movement performed in the highest levels of dressage competition. The ground reaction forces (GRFs) of horses performing the piaffe do not appear to have been reported. Therefore, the objective of this study was to describe three-dimensional GRFs in ridden dressage horses performing the piaffe. In-ground force plates were used to capture fore and hindlimb GRF data from seven well-trained dressage horses. Peak vertical GRF was significantly higher in forelimbs than in the hindlimbs (7.39 ± 0.99 N/kg vs. 6.41 ± 0.64 N/kg; < 0.001) with ve...
St George LB, Pugliese BR, Hobbs SJ, Brisbois AL, Sinclair JK, Kirker-Head CA.To investigate the effects of novel legwear designed to limit metacarpophalangeal joint (MCPJ) extension and redirect loading forces from the flexor apparatus through analyses of 2-D kinematic and kinetic data. Methods: 6 adult horses without musculoskeletal disease. Methods: Horses were subjected to 4 treatments: control (no legwear), inactive legwear (unlimited legwear extension), and active legwear with mild (30°) and moderate (20°) legwear extension limitation. Two-dimensional kinematic data were collected for the right forelimb (FL) during walk and trot and from leading and trailing FLs...
Serra Bragança FM, Hernlund E, Thomsen MH, Waldern NM, Rhodin M, Byström A, van Weeren PR, Weishaupt MA.There is a paucity of research describing the gait pattern of lame horses at the walk. Objective: To describe the changes in motion pattern and vertical ground reaction forces (GRFz) in horses with induced forelimb lameness at the walk and compare those changes with the changes observed at the trot. Methods: Experimental study. Methods: In 10 clinically sound Warmblood horses, moderate forelimb lameness was induced using a sole pressure model followed by trot and walk on a treadmill. Kinematic data were collected using 3D optical motion capture (OMC), and GRFz by an instrumented treadmill. Mix...
Linford N, MacKechnie-Guire R, Cassar M.The aim of this trial project was to identify whether buried archaeological remains may have an influence on equine locomotion, through comparison with a non-invasive Ground Penetrating Radar (GPR) survey. This study was conducted at the world-renowned Burghley Horse Trials site, near Stamford, City of Peterborough, U.K. that has a diverse range of heritage assets throughout the wider park land centred on the Grade 1 listed Elizabethan Burghley House. The initial aim of the research was to first use geophysical survey to identify and characterise archaeological remains, and then to determine a...
Byström A, Clayton HM, Hernlund E, Roepstorff L, Rhodin M, Bragança FS, Engell MT, van Weeren R, Weishaupt MA, Egenvall A.Left-right movement symmetry is a highly desirable characteristic in sport horses. Objective: This study compared movement symmetry in well-trained dressage horses in unridden and unrestrained position and ridden in a dressage frame, and investigated possible associations between gaits. Methods: Experimental study. Methods: Seven sound, high-level dressage horses were measured at walk and sitting trot on a treadmill at several speeds under two conditions: with and without rider. Left-right differences in stance duration, stance protraction and retraction based on longitudinal hoof positions, i...
Clayton HM, Hobbs SJ.Gaits are typically classified as walking or running based on kinematics, the shape of the vertical ground reaction force (GRF) curve, and the use of inverted pendulum or spring-mass mechanics during the stance phase. The objectives of this review were to describe the biomechanical characteristics that differentiate walking and running gaits, then apply these criteria to classify and compare the enhanced natural gait of collected trot with the artificial gaits of passage and piaffe as performed by highly trained dressage horses. Limb contact and lift off times were used to determine contact se...
Hobbs SJ, Clayton HM.One of the goals of the neuromotor control system is to minimize the cost of locomotion by reducing mechanical energy losses. Collisional mechanics, which studies the redirection of the downwards motion of the center of mass (COM) by ground reaction forces (GRF) generated by the limbs, represents an important source of energy loss. The primary objective of this study was to compare collisional mechanics and the associated mechanical energy losses in horses performing diagonally-synchronized gaits over a range of speeds. It is to be expected that collisional energy losses will be high when the ...
Self Davies ZT, Spence AJ, Wilson AM.The horse has evolved to gallop economically at high speed. Limb force increases with speed but direct measures of limb ground reaction forces (GRFs) at gallop are sparse. This study reports GRFs for multiple limbs, using force plates, across seven Thoroughbred racehorses during ridden galloping. The results show peak vertical GRF values of 13.6 N kg (non-lead hindlimb), 12.3 N kg (lead hindlimb), 14.0 N kg (non-lead forelimb) and 13.6 N kg (lead forelimb) at 11.4 m s and recorded values are consistent with those predicted from duty factor. The distribution of body weight b...
Clayton HM, Hobbs SJ.Legged locomotion results from the feet pressing against the ground to generate ground reaction forces (GRFs) that are responsible for moving the body. By changing limb coordination patterns and muscle forces, the GRFs are adjusted to allow the horse to move in different gaits, speeds, and directions with appropriate balance and self-carriage. This article describes the typical GRF patterns in each gait, the adaptations that produce turning, and the GRF patterns used to unload the painful limb when the horse is lame. The intent is to provide information that is of practical interest and value ...
Schoonover MJ, Whitfield CT, Young JM, Sippel KM, Payton ME.OBJECTIVE To determine effects for 2 IV regional limb perfusion (IVRLP) protocols involving tiludronate on lameness of horses with navicular syndrome. ANIMALS 15 horses with bilateral forelimb navicular syndrome. PROCEDURES Shoeing and anti-inflammatory injection into the distal interphalangeal joint (DIPJ) of both forelimbs (day 0) were performed on all horses. On day 14, horses received 1 of 3 IVRLPs consisting of 0.1 mg of tiludronate/kg (low-dose tiludronate [LDT]; n = 5), 0.2 mg of tiludronate/kg (high-dose tiludronate [HDT]; 5), or saline (0.9% NaCl) solution (placebo; 5); treatments wer...
Byström A, Egenvall A, Roepstorff L, Rhodin M, Bragança FS, Hernlund E, van Weeren R, Weishaupt MA, Clayton HM.The walk and trot are inherently symmetrical gaits, making them potentially suitable for the detection of left-right asymmetries. The aims of this study were to describe asymmetrical vertical excursions of the withers at walk in non-lame high-level dressage horses and to seek associations between these asymmetric movements and other kinematic variables and vertical ground reaction forces (vGRFs). Seven dressage horses, judged clinically as being sound, walked unridden and unrestrained on a treadmill with an integrated force measuring system (480 Hz), from which spatiotemporal and vGRF variable...
Hobbs SJ, Nauwelaerts S, Sinclair J, Clayton HM, Back W.Asymmetry in forelimb dorsal hoof wall angles, termed unevenness, is associated with forelimb gait asymmetries, but compensatory mechanisms and out of plane ground reaction forces (GRFs) due to unevenness have yet to be documented. The aim of this study was therefore to investigate the effects of fore hoof unevenness on contralateral fore and hind limb force vectors patterns, in both sagittal and frontal planes. A group of n = 34 riding horses were classified into four groups: hoof angle difference of more than 1.5 degrees (UNEVEN; n = 27), including higher left fore (HIGH-LF; n = 12), higher ...
Barstow A, Bailey J, Campbell J, Harris C, Weller R, Pfau T.Both pleasure and competition horses regularly exercise on surfaces such as tarmac, gravel and turf during 'hacking'. Despite this, there is limited evidence relating to the effect of these surfaces upon foot-surface interaction. Objective: To investigate forelimb foot placement, hoof vibration and movement symmetry in pleasure horses on three commonly encountered hacking surfaces. Methods: Quantitative gait study in a convenience sample. Methods: Six horses regularly partaking in hacking exercise were ridden in walk and trot on all surfaces. Horses were equipped with one hoof-mounted, acceler...
Hobbs SJ, Robinson MA, Clayton HM.Ground reaction forces (GRF) measured during equine gait analysis are typically evaluated by analyzing discrete values obtained from continuous force-time data for the vertical, longitudinal and transverse GRF components. This paper describes a simple, temporo-spatial method of displaying and analyzing sagittal plane GRF vectors. In addition, the application of statistical parametric mapping (SPM) is introduced to analyse differences between contra-lateral fore and hindlimb force-time curves throughout the stance phase. The overall aim of the study was to demonstrate alternative methods of eva...
Biewener AA.The stresses acting in muscle-tendon units and ligaments of the forelimb and hindlimb of horses were determined over a range of speed and gait based on recordings of ground reaction forces and limb kinematics. Maximum stresses of 40-50 MPa were calculated to act in several of the principal forelimb (superficial digital flexor (SDF), deep digital flexor (DDF), ulnaris lateralis (UL) and flexor carpi ulnaris/radialis (FCU/R)) and hindlimb tendons (plantaris, DDF) at the fastest galloping speeds recorded (up to 7.4 m s-1). Smaller stresses were found for the gastrocnemius (GAST) tendon (30 MPa) a...
Witte TH, Knill K, Wilson AM.Measurement of peak vertical ground reaction force (GRFz) from multiple limbs simultaneously during high-speed, over-ground locomotion would enhance our understanding of the locomotor mechanics of cursorial animals. Here, we evaluate the accuracy of predicting peak GRFz from duty factor (the proportion of the stride for which the limb is in contact with the ground). Foot-mounted uniaxial accelerometers, combined with UHF FM telemetry, are shown to be practical and accurate for the field measurement of stride timing variables, including duty factor. Direct comparison with the force plate produc...
McGuigan MP, Wilson AM.A horse's legs are compressed during the stance phase, storing and then returning elastic strain energy in spring-like muscle-tendon units. The arrangement of the muscle-tendon units around the lever-like joints means that as the leg shortens the muscle-tendon units are stretched. The forelimb anatomy means that the leg can be conceptually divided into two springs: the proximal spring, from the scapula to the elbow, and the distal spring, from the elbow to the foot. In this paper we report the results of a series of experiments testing the hypothesis that there is minimal scope for muscle cont...
Bertram JE, Gutmann A.Mammals use two distinct gallops referred to as the transverse (where landing and take-off are contralateral) and rotary (where landing and take-off are ipsilateral). These two gallops are used by a variety of mammals, but the transverse gallop is epitomized by the horse and the rotary gallop by the cheetah. In this paper, we argue that the fundamental difference between these gaits is determined by which set of limbs, fore or hind, initiates the transition of the centre of mass from a downward-forward to upward-forward trajectory that occurs between the main ballistic (non-contact) portions o...
Bell RP, Reed SK, Schoonover MJ, Whitfield CT, Yonezawa Y, Maki H, Pai PF, Keegan KG.To investigate associations between inertial sensor and stationary force plate measurements of hind limb lameness in horses. Methods: 21 adult horses with no lameness or with mild hind limb lameness. Methods: Horses were instrumented with inertial sensors and evaluated for lameness with a stationary force plate while trotting in a straight line. Inertial sensor-derived measurements of maximum and minimum pelvic height differences between right and left halves of the stride were compared with vertical and horizontal ground reaction forces (GRFs). Stepwise linear regression was performed to inve...
Dutto DJ, Hoyt DF, Cogger EA, Wickler SJ.Although the forces required to support the body mass are not elevated when moving up an incline, kinematic studies, in vivo tendon and bone studies and kinetic studies suggest there is a shift in forces from the fore- to the hindlimbs in quadrupeds. However, there are no whole-animal kinetic measurements of incline locomotion. Based on previous related research, we hypothesized that there would be a shift in forces to the hindlimb. The present study measured the force produced by the fore- and hindlimbs of horses while trotting over a range of speeds (2.5 to 5 m s(-1)) on both level and up an...
Merkens HW, Schamhardt HC, Van Osch GJ, Van den Bogert AJ.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...
Weishaupt MA, Wiestner T, Hogg HP, Jordan P, Auer JA.The compensatory mechanisms of horses with weightbearing hindlimb lameness are still not fully understood. Objective: That weightbearing, unilateral hindlimb lameness would not only alter stride characteristics to diminish structural stress in the affected limb but also induce compensatory load adjustments in the other supporting limbs. Objective: To document the load and time shifting mechanisms of horses with unilateral weightbearing hindlimb lameness. Methods: Reversible lameness was induced in 8 clinically sound horses by applying a solar pressure model. Three degrees of lameness (subtle, ...
Hobbs SJ, Clayton HM.The aims of this study were to measure ground reaction forces (GRFs) of concurrently loaded limbs and to evaluate spatial relationships between the centre of pressure (COP) and centre of mass (COM) in trotting horses. Kinematic (120Hz) and GRF data were collected at trot from three trials of eight horses using four force plates (960 Hz). Forelimb and hind limb GRFs were measured, COP was calculated from the resultant vertical GRF vector and COM was calculated by summation of weighted segmental COMs. Peak total vertical force (19.3 ± 1.3N/kg at 45.1 ± 2.3% diagonal stance) coincided with zero...
Witte H, Biltzinger J, Hackert R, Schilling N, Schmidt M, Reich C, Fischer MS.In three species of small therian mammals (Scandentia: Tupaia glis, Rodentia: Galea musteloides and Lagomorpha: Ochotona rufescens) the net joint forces and torques acting during stance phase in the four kinematically relevant joints of the forelimbs (scapular pivot, shoulder joint, elbow joint, wrist joint) and the hindlimbs (hip joint, knee joint, ankle joint, intratarsal joint) were determined by inverse dynamic analysis. Kinematics were measured by cineradiography (150 frames s(-1)). Synchronously ground reaction forces were acquired by forceplates. Morphometry of the extremities was perfo...
Oosterlinck M, Pille F, Huppes T, Gasthuys F, Back W.Modern pressure plates (PP) could be an alternative to traditional force plates (FP) for quantitative equine gait analysis, thereby providing the clinician with objective data on the horse's gait while unravelling the loading of different regions of the hoof during the stance phase. The aim of this study was to determine whether a stand-alone PP allows reliable measurement of gait kinetics, compared to simultaneously recorded FP variables. Six sound Warmblood horses were walked and trotted over a combined PP and FP system for collection of a set of five valid kinetic measurements for each fore...
Chateau H, Camus M, Holden-Douilly L, Falala S, Ravary B, Vergari C, Lepley J, Denoix JM, Pourcelot P, Crevier-Denoix N.Circling increases the expression of distal forelimb lameness in the horse, depending on rein, diameter and surface properties of the circle. However, there is limited information about the kinetics of horses trotting on circles. The aim of this study was to quantify ground reaction force (GRF) and moments in the inside and outside forelimb of horses trotting on circles and to compare the results obtained on different ground surfaces. The right front hoof of six horses was equipped with a dynamometric horseshoe, allowing the measurement of 3-dimensional GRF, moments and trajectory of the centr...
Clayton HM, Hobbs SJ.Gaits are typically classified as walking or running based on kinematics, the shape of the vertical ground reaction force (GRF) curve, and the use of inverted pendulum or spring-mass mechanics during the stance phase. The objectives of this review were to describe the biomechanical characteristics that differentiate walking and running gaits, then apply these criteria to classify and compare the enhanced natural gait of collected trot with the artificial gaits of passage and piaffe as performed by highly trained dressage horses. Limb contact and lift off times were used to determine contact se...
Clayton HM, Nauwelaerts S.In a standing horse the centre of pressure (COP), measured as the resultant vertical ground reaction force (GRF) of all supporting limbs, is adjusted in response to visual, vestibular and proprioceptive information. Stabilographic analysis measures balance by tracking COP movements in the horizontal plane. Loss of visual input affects stability of balance in people and has clinical implications in that instability inherent in some neurological diseases increases with the eyes closed. The objectives of this study were to evaluate the visual contribution to postural stability in horses. The hypo...
Setterbo JJ, Garcia TC, Campbell IP, Reese JL, Morgan JM, Kim SY, Hubbard M, Stover SM.To compare hoof acceleration and ground reaction force (GRF) data among dirt, synthetic, and turf surfaces in Thoroughbred racehorses. Methods: 3 healthy Thoroughbred racehorses. Methods: Forelimb hoof accelerations and GRFs were measured with an accelerometer and a dynamometric horseshoe during trot and canter on dirt, synthetic, and turf track surfaces at a racecourse. Maxima, minima, temporal components, and a measure of vibration were extracted from the data. Acceleration and GRF variables were compared statistically among surfaces. Results: The synthetic surface often had the lowest peak ...
Biknevicius AR, Mullineaux DR, Clayton HM.Gaited horses employ 4-beat stepping (singlefoot) gaits that extend into speeds typical of trots. Ground reaction force (GRF) patterns of these specialised gaits have not been reported; therefore, appraisal of these gaits using nongaited horse kinetics may lead to clinical misjudgements. Objective: GRFs of tölting Icelandic horses will be comparable in profile and magnitude with those of trotting horses. Methods: Forelimb and hindlimb GRFs were obtained for 10 Icelandic horses ridden at a tölt. These data were evaluated across 3 speed ranges: <2, 2.5-5 and >5 m/sec. Results: Virtually all ve...
Eliashar E, McGuigan MP, Wilson AM.Collapsed heels conformation has been implicated as causing radical biomechanical alterations, predisposing horses to navicular disease. However, the correlation between hoof conformation and the forces exerted on the navicular bone has not been documented. Objective: The angle of the distal phalanx in relation to the ground is correlated to the degree of heel collapse and foot conformation is correlated to the compressive force exerted by the deep digital flexor tendon on the navicular bone. Methods: Thirty-one shod Irish Draught-cross type horses in routine work and farriery care were trotte...
Hobbs SJ, Richards J, Clayton HM.The diagonal limb support pattern at trot provides pitch and roll stability, but little is known about the control of moments about the centre of mass (COM) in horses. Correct COM location is critical in the calculation of pitching moments. The objectives were to determine the effect of COM location on pitching moments in trotting horses and explore how COM location could influence balance. Kinematic (120 Hz) and GRF (4 force plates, 960 Hz) data were collected at trot from three trials of eight horses. The position of the COM was determined from the weighted summation of the segmental COMs an...
Clayton HM, Lanovaz JL, Schamhardt HC, van Wessum R.Ground reaction force (GRF) measurements are often normalised to body mass to facilitate inter-individual comparisons. The objective of this study was to explore the effect of a rider on the GRFs and fetlock joint kinematics of trotting horses. The subjects were 5 dressage-trained horses and 3 experienced dressage riders. Ground reaction force measurements and sagittal view videotapes were recorded as the horses trotted at the same velocity in hand (3.49 +/- 0.52 m/s) and with a rider (3.49 +/- 0.46 m/s). Data were time-normalised to stance duration. Ground reaction force measurements were exp...
Nauwelaerts S, Malone SR, Clayton HM.This study used stabilographic analysis to measure and describe changes in stability during standing in foals from birth to 5 months of age. Stabilographic analysis was performed on newborn foals immediately after first suckling then daily until 1 week of age, weekly until 1 month of age and monthly until 5 months of age. Ground reaction force (GRF) data were collected for periods of 8s with the foal standing on one or two force plates recording at 1000 Hz. Stabilographic variables describing the amplitude, velocity and frequency of center of pressure (COP) movements were derived from the GRF ...
Clayton HM, Hobbs SJ.Locomotion results from the generation of ground reaction forces (GRF) that cause translations of the center of mass (COM) and generate moments that rotate the body around the COM. The trot is a diagonally-synchronized gait performed by horses at intermediate locomotor speeds. Passage is a variant of the trot performed by highly-trained dressage horses. It is distinguished from trot by having a slow speed of progression combined with great animation of the limbs in the swing phase. The slow speed of passage challenges the horse's ability to control the sagittal-plane moments around the COM. Fo...
Byström A, Egenvall A, Roepstorff L, Rhodin M, Bragança FS, Hernlund E, van Weeren R, Weishaupt MA, Clayton HM.The walk and trot are inherently symmetrical gaits, making them potentially suitable for the detection of left-right asymmetries. The aims of this study were to describe asymmetrical vertical excursions of the withers at walk in non-lame high-level dressage horses and to seek associations between these asymmetric movements and other kinematic variables and vertical ground reaction forces (vGRFs). Seven dressage horses, judged clinically as being sound, walked unridden and unrestrained on a treadmill with an integrated force measuring system (480 Hz), from which spatiotemporal and vGRF variable...
Wiggers N, Nauwelaerts SL, Hobbs SJ, Bool S, Wolschrijn CF, Back W.Left-right symmetrical distal limb conformation can be an important prerequisite for a successful performance, and it is often hypothesized that asymmetric or uneven feet are important enhancing factors for the development of lameness. On a population level, it has been demonstrated that uneven footed horses are retiring earlier from elite level competition, but the biomechanical consequences are not yet known. The objectives of this study were to compare the functional locomotor asymmetries of horses with uneven to those with even feet. Hoof kinetics and distal limb kinematics were collected ...
Moleman M, van Heel MC, van Weeren PR, Back W.There is little insight into the effects of routine farriery on the internal structures of the distal limb in sound horses. Objective: To measure the effect of change in hoof conformation during a shoeing interval on the moments about the proximal and distal interphalangeal joints (PIPJ, DIPJ) and to determine whether and how the horse compensates for this change in hoof conformation. Methods: Both front feet of 9 sound Warmblood horses were measured while standing on a pressure-force measuring system and radiographed in a lateromedial direction shortly after shoeing and 8 weeks later. From th...
Serra Bragança FM, Hernlund E, Thomsen MH, Waldern NM, Rhodin M, Byström A, van Weeren PR, Weishaupt MA.There is a paucity of research describing the gait pattern of lame horses at the walk. Objective: To describe the changes in motion pattern and vertical ground reaction forces (GRFz) in horses with induced forelimb lameness at the walk and compare those changes with the changes observed at the trot. Methods: Experimental study. Methods: In 10 clinically sound Warmblood horses, moderate forelimb lameness was induced using a sole pressure model followed by trot and walk on a treadmill. Kinematic data were collected using 3D optical motion capture (OMC), and GRFz by an instrumented treadmill. Mix...
Riemersma DJ, van den Bogert AJ, Jansen MO, Schamhardt HC.Strains in the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), accessory ligament of the deep digital flexor muscle (inferior check ligament [ICL]) and the interosseus medius muscle (suspensory ligament [SL]) in the right forelimb of 5 ponies were measured using mercury-in-silastic strain gauges a few hours after implantation. Tendon strains were recorded at the walk with normal flat shoes, egg-bar shoes, a 7 degrees increased hoof angle accomplished by application of a heel-wedge and a 7 degrees decreased hoof angle using a toe-wedge, consecutively. Ground reactio...
Hodson E, Clayton HM, Lanovaz JL.Video (60 Hz) and force (2000 Hz) data were collected from 5 sound horses during walking. Forelimb data were analysed for 8 strides (4 left, 4 right) per horse to determine sagittal plane kinematics and ground reaction forces (GRFs). The results suggested that brachial rotation was responsible for protraction and retraction of the limb as a whole, while rotations of the scapula and antebrachium elevated the distal limb during breakover and early swing then lowered it in preparation for ground contact. The coffin joint was flexed maximally at the time of peak longitudinal braking force, which o...
Clayton HM, Schamhardt HC, Willemen MA, Lanovaz JL, Colborne GR.To measure and correlate kinematic and ground reaction force (GRF) data in horses with superficial digital flexor tendinitis. Methods: 6 sound horses. Methods: Horses were evaluated before (sound evaluation) and after (lame evaluation) induction of superficial digital flexor tendinitis in 1 forelimb (randomized) by injection of collagenase. As each horse trotted, kinematic data were collected by use of an optoelectronic system, and GRF data were measured by use of a force plate. Three-dimensional kinematic and GRF data were projected onto a 2-dimensional sagittal plane. Results: Lame limbs had...
Merkens HW, Schamhardt HC.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...
Gomez Alvarez CB, Bobbert MF, Lamers L, Johnston C, Back W, van Weeren PR.There are no detailed studies describing a relationship between hindlimb lameness and altered motion of the back. Objective: To quantify the effect of induced subtle hindlimb lameness on thoracolumbar kinematics in the horse. Methods: Kinematics of 6 riding horses were measured during walk and trot on a treadmill before and during application of pressure on the sole of the left hindlimb using a well-established sole pressure model. Reflective markers were located at anatomical landmarks on the limbs, back, head and neck for kinematic recordings. Ground reaction forces (GRF) in individual limbs...
