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Topic:Ground Reaction Forces

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.
Effects of subject velocity on ground reaction force measurements and stance times in clinically normal horses at the walk and trot.
American journal of veterinary research    January 1, 1996   Volume 57, Issue 1 7-11 
McLaughlin RM, Gaughan EM, Roush JK, Skaggs CL.The objective of the study reported here was to evaluate the effects of changing velocity on stance time and ground reaction force (GRF) measurements in horses at the walk and trot. Methods: Force plate gait analysis was used to evaluate clinically normal horses at variable velocities. Ground reaction force measurements and stance times were recorded and compared. Methods: 12 adult horses. Methods: Data were obtained from 192 valid trials at the walk and 162 valid trials at the trot. Vertical, braking, and propulsive peak forces and impulses were measured. Pearson's correlation coefficients we...
Load redistribution after desmotomy of the accessory ligament of the deep digital flexor tendon in adult horses.
The veterinary quarterly    January 1, 1996   Volume 18 Suppl 2 S70-S74 
Buchner HH, Savelberg HH, Becker CK.An analysis of joint moments was used to study the biomechanical implications, load redistribution and kinematic pattern following desmotomy of the accessory ligament of the deep digital flexor tendon (AL) in adult horses. Recordings of 6 sound horses were made before and 10 days after desmotomy of the AL of the right forelimb at the walk and the trot. Kinematic recordings of the right forelimb and the left distal forelimb were made using the CODA-3 system. Kinetic recordings of the ground reaction forces in both forelimbs were made using a Kistler force plate simultaneously with the kinematic...
The effect of diagnostic regional nerve blocks in the fore limb on the locomotion of clinically sound horses.
The veterinary quarterly    January 1, 1996   Volume 18 Suppl 2 S106-S109 
Keg PR, Schamhardt HC, van Weeren PR, Barneveld A.The practice of applying diagnostic nerve blocks relies on the assumption that the blocks in themselves do not alter the horse's gait. This assumption has recently been challenged. In the present paper a series of sequential nerve blocks (low palmar digital block, abaxial sesamoid block, high palmar block) was applied to clinically sound horses. Before and after each block the gait was clinically scored and Ground Reaction Forces (GRF) were measured. Clinical scoring did not change after any of the nerve blocks. None of the GRF variables changed significantly except for a slight alteration of ...
The effect of the high palmar nerve block and the ulnar nerve block on lameness provoked by a collagenase-induced tendonitis of the lateral branch of the suspensory ligament.
The veterinary quarterly    January 1, 1996   Volume 18 Suppl 2 S103-S105 
Keg PR, Schamhardt HC, van Weeren PR, Barneveld A.Controversy exists with respect to the innervation of the suspensory ligament (SL) in the fore limb of the horse. It is uncertain whether this structure is exclusively innervated by branches of the ulnar nerve or also to some extent by median nerve branches. Ground Reaction Forces (GRF) were determined in horses before and after the induction of a tendonitis in the lateral branch of the SL by the injection of collagenase, and before and after a high palmar and an ulnar block respectively. The high palmar block succeeded in bringing all GRF variables back to their original values which the ulna...
Parameters of forelimb ground reaction force in 48 normal ponies.
The Veterinary record    March 25, 1995   Volume 136, Issue 12 283-286 doi: 10.1136/vr.136.12.283
Barr AR, Dow SM, Goodship AE.Recordings of forelimb ground reaction forces were made from 48 normal ponies moving at the trot, to evaluate the relationships between bodyweight, vertical ground reaction forces, the timing of individual events within the stance phase and the total contact time. There were highly significant correlations between the mean vertical ground reaction forces and bodyweight. The mean vertical ground reaction forces, corrected for bodyweight, were inversely correlated with the total contact time suggesting that higher trotting speeds may be associated with greater vertical ground reaction forces. Th...
Semi-quantitative analysis of hoof-strike in the horse.
Journal of biomechanics    August 1, 1994   Volume 27, Issue 8 997-1004 doi: 10.1016/0021-9290(94)90216-x
Hjertén G, Drevemo S.The initial forelimb loading of a horse trotting at 3.7 ms-1 on a treadmill was studied by use of an instrumented shoe, accelerometers and high-speed cinematography. At the beginning of the stance phase the forelimb was loaded successively from the hoof. This is suggested to be an important factor for effective shock force absorbency in the extremities. Shearing forces may appear in the carpus before the onset of the longitudinal loading of the limb. These forces are proposed to depend on speed, locomotion pattern and the friction and hardness of the surface. It is suggested that shearing forc...
Effect of central or marginal location and post-operative exercise on the healing of osteochondral defects in the equine carpus.
Equine veterinary journal    January 1, 1994   Volume 26, Issue 1 33-39 doi: 10.1111/j.2042-3306.1994.tb04327.x
Barr AR, Wotton SF, Dow SM, Waterman AE, Goodship AE, Duance VC.The effects of osteochondral defect location and post-operative walking exercise on structural repair and recovery of joint function were examined in the midcarpal joints of ponies. Functional recovery was monitored by measuring ground reaction forces using a force plate. Structural repair was evaluated histologically and by measuring the total collagen and uronic acid content and relative proportions of Type I and II collagen in the repair tissue. Central defects tended to cause a more marked functional disturbance but were repaired with fibrocartilage rather than fibrous tissue in 3 out of 6...
Ground reaction force patterns of Dutch Warmbloods at the canter.
American journal of veterinary research    May 1, 1993   Volume 54, Issue 5 670-674 
Merkens HW, Schamhardt HC, van Osch GJ, Hartman W.Ground reaction force (GRF) patterns from 20 clinically sound Dutch Warmbloods were recorded at the right fore-leading canter, and a standard horse was composed. These GRF data for the standard can be used for evaluation of jumping horses. The GRF patterns were asymmetric for all 4 limbs. The leading right forelimb decelerated the body. The trailing left forelimb propelled the body and decelerated it slightly. The trailing left hind limb propelled, and the leading right hind limb contributed to deceleration and propulsion. Referred to the maximal vertical load of the leading right forelimb, th...
External loads on the limbs of jumping horses at take-off and landing.
American journal of veterinary research    May 1, 1993   Volume 54, Issue 5 675-680 
Schambardt HC, Merkens HW, Vogel V, Willekens C.Using a force plate, ground reaction force (GRF) patterns at take-off and landing between the hooves and the ground were recorded for all limbs of 5 Dutch Warmbloods jumping a 0.8-m vertical fence from the right-leading canter. Distribution of the GRF and force impulses over the 4 limbs at take-off and landing were considerably different from those recorded at the normal canter. At take-off, the propulsory GRF of the hind limbs were 3 to 5 times higher than at the normal canter, depending on the jumping technique of the horse. At landing, the propulsory GRF were mainly increased in the trailin...
Ground reaction force patterns of Dutch warmblood horses at normal trot.
Equine veterinary journal    March 1, 1993   Volume 25, Issue 2 134-137 doi: 10.1111/j.2042-3306.1993.tb02923.x
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...
Determination of the center of pressure of the hoofs of the forelimbs of horses standing on a flat level surface.
Acta anatomica    January 1, 1993   Volume 146, Issue 2-3 175-178 doi: 10.1159/000147441
Colahan P, Lindsey E, Nunier C.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.
Acta anatomica    January 1, 1993   Volume 146, Issue 2-3 162-167 doi: 10.1159/000147439
Jansen MO, van den Bogert AJ, Riemersma DJ, Schamhardt HC.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...
Concept of a force-measuring horseshoe.
Acta anatomica    January 1, 1993   Volume 146, Issue 2-3 114-119 doi: 10.1159/000147431
Roepstorff L, Drevemo S.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...
Identification of subclinical tendon injury from ground reaction force analysis.
Equine veterinary journal    July 1, 1991   Volume 23, Issue 4 266-272 doi: 10.1111/j.2042-3306.1991.tb03715.x
Dow SM, Leendertz JA, Silver IA, Goodship AE.In this study a method of analysing ground reaction forces was developed to help in the diagnosis of subclinical flexor tendon injury. A Kistler force plate was used to obtain records from a population of Thoroughbreds in National Hunt training over a period of two years. Characteristic features of the force patterns generated were measured and shown to have low variance, both between horses and over a period of two racing seasons in animals that were sound throughout the trial. Specific changes in the loading pattern of the limb, which correlated with injury of the superficial digital flexor ...
[Force plate measurements for a quantitative assessment of the equine gait].
Tijdschrift voor diergeneeskunde    December 15, 1990   Volume 115, Issue 24 1182-1189 
Merkens HW.Forces occurring between the hoof and the ground during the stance phase (i.e. the ground reaction forces GRF) can be analysed using a force plate. The average of a number of five to stance time and body weight normalised GRF recordings (data) will provide 'representative' GRF patterns. These can be used for objective and quantitative evaluation of various forms of therapy in equine orthopaedics as well as for locomotion research during various forms of equestrian sports.
Simulation of quadrupedal locomotion using a rigid body model.
Journal of biomechanics    January 1, 1989   Volume 22, Issue 1 33-41 doi: 10.1016/0021-9290(89)90182-6
van den Bogert AJ, Schamhardt HC, Crowe A.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...
Evaluation of equine locomotion during different degrees of experimentally induced lameness. II: Distribution of ground reaction force patterns of the concurrently loaded limbs.
Equine veterinary journal. Supplement    September 1, 1988   Issue 6 107-112 doi: 10.1111/j.2042-3306.1988.tb04656.x
Merkens HW, Schamhardt HC.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...
Evaluation of equine locomotion during different degrees of experimentally induced lameness. I: Lameness model and quantification of ground reaction force patterns of the limbs.
Equine veterinary journal. Supplement    September 1, 1988   Issue 6 99-106 doi: 10.1111/j.2042-3306.1988.tb04655.x
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...
Kinetics and kinematics of the equine hind limb: in vivo tendon loads and force plate measurements in ponies.
American journal of veterinary research    August 1, 1988   Volume 49, Issue 8 1344-1352 
Riemersma DJ, Schamhardt HC, Hartman W, Lammertink JL.Loads on the suspensory ligament, deep digital flexor tendon, superficial digital flexor tendon, and long digital extensor tendon of the equine hind limb were determined in ponies by use of implanted strain gauges consisting of silicone rubber tubes filled with mercury. Recordings were made simultaneously with force plate measurements and high-speed film recordings while the ponies were walking. The relationship between strain gauge signals and tendon loads was obtained from tension-strain tests performed after death of the ponies. The suspensory ligament and the 2 digital flexor tendons were ...
Distribution of ground reaction forces of the concurrently loaded limbs of the Dutch Warmblood horse at the normal walk.
Equine veterinary journal    May 1, 1988   Volume 20, Issue 3 209-213 doi: 10.1111/j.2042-3306.1988.tb01501.x
Merkens HW, Schamhardt HC.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...
The use of H(orse) INDEX: a method of analysing the ground reaction force patterns of lame and normal gaited horses at the walk.
Equine veterinary journal    January 1, 1988   Volume 20, Issue 1 29-36 doi: 10.1111/j.2042-3306.1988.tb01448.x
Merkens HW, Schamhardt HC, Hartman W, Kersjes AW.The amplitudes, impulses and times of occurrence of a number of selected peaks in the ground reaction force tracings of 17 horses with various clinical histories were compared with those of 20 horses used to establish values for the 'standard' Dutch Warmblood horse. The resulting factors were combined, using different weighting factors, into indices characterising each limb. The symmetry between the loading of the forelimbs and the hindlimbs was used to calculate amplitude and peak-time symmetry indices. Limb and symmetry indices were combined in one H(orse) INDEX. This method of quantifying t...
Quantification of equine ground reaction force patterns.
Journal of biomechanics    January 1, 1987   Volume 20, Issue 4 443-446 doi: 10.1016/0021-9290(87)90051-0
Schamhardt HC, Merkens HW.A method was developed to quantify the ground reaction force pattern of the horse. A number of selected force amplitudes and peak-time positions in the normalized stance phase of left and right contralateral limbs were used to calculate symmetry indices. Data from each limb were compared with those of a 'standard horse' resulting in limb indices. The combination of amplitude and peak-time symmetry and limb indices yielded one H(orse)INDEX. These indices were useful for comparison of different horses and for the evaluation of lameness and treatment.
The ground reaction force pattern from the hindlimb of the horse simulated by a spring model.
Acta anatomica    January 1, 1987   Volume 129, Issue 1 31-33 doi: 10.1159/000146374
van Gurp M, Schamhardt HC, Crowe A.A model consisting of a spring loaded by a time-dependent mass is presented simulating the vertical and longitudinal horizontal ground reaction force patterns obtained from the hindlimb of a walking horse.
Software for analysis of equine ground reaction force data.
Computer methods and programs in biomedicine    December 1, 1986   Volume 23, Issue 3 247-253 doi: 10.1016/0169-2607(86)90058-1
Schamhardt HC, Merkens HW, Lammertink JL.Software for analysis of force plate recordings of the horse at normal walk is described. The data of a number of stance phases are averaged to obtain a representative tracing of that horse. The amplitudes of a number of characteristic peaks in the force-time curves are used to compare left and right front limbs and left and right hind limbs. The averaged tracings are plotted, default on the line printer or, via separate program, on a high quality pen plotter. A version of the program applicable for analysis of human force plate recordings, is available.
Ground reaction force patterns of Dutch Warmblood horses at normal walk.
Equine veterinary journal    May 1, 1986   Volume 18, Issue 3 207-214 doi: 10.1111/j.2042-3306.1986.tb03600.x
Merkens HW, Schamhardt HC, Hartman W, Kersjes AW.The ground reaction force patterns from 20 clinically sound Dutch Warmblood horses (Group A) were recorded at the normal walk. The data from four to 10 stance phases of each limb were computer averaged after normalisation to the animal's body mass and to the stance time. This analysis method allowed comparison of data from left and right fore- and hindlimbs within and between horses. The left-to-right symmetry in the reaction force peaks of contralateral limbs of one horse exceeded 90 per cent. The time in the stance phase at which the peaks occur were even more symmetrically distributed. A ch...
Electrocution of horses by a “hot” ground.
The Canadian veterinary journal = La revue veterinaire canadienne    March 1, 1983   Volume 24, Issue 3 66 
Brackett JB.No abstract available
Modifications of a force plate system for equine gait analysis.
American journal of veterinary research    March 1, 1982   Volume 43, Issue 3 538-540 
Steiss JE, Yuill GT, White NA, Bowen JM.A force plate system for measurement of the vertical component of the force applied by a horse's limb on ground contact was modified. The modifications included use of steel supporting posts for improved durability and an additional strain gauge on each arm of the Wheatstone bridge for increased sensitivity and temperature compensation. Data from clinically normal horses are provided to indicate the performance obtained with these modifications of the force plate system.
Interaction of hoof with ground.
Modern veterinary practice    July 1, 1977   Volume 58, Issue 7 624-625 
Rooney JR.No abstract available
Force plate studies of equine biomechanics.
American journal of veterinary research    November 1, 1976   Volume 37, Issue 11 1251-1255 
Pratt GW, O'Connor JT.The force plate can measure a wide range of effects in the horse. The same instrument can record forces from more than a ton in the galloping animal to 25 g associated with the action of the heart. In all probability, the force plate will develop into a valuable clinical instrument.
Impact force measurement using preloaded transducers.
American journal of veterinary research    December 1, 1970   Volume 31, Issue 12 2279-2283 
Frederick FH, Henderson JM.No abstract available