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.
Clinical evaluation of the effects of immobilization followed by remobilization and exercise on the metacarpophalangeal joint in horses. To evaluate clinical effects of immobilization followed by remobilization and exercise on the metacarpophalangeal joint (MPJ) in horses. Methods: 5 healthy horses. Methods: After lameness, radiographic, and force plate examinations to determine musculoskeletal health, 1 forelimb of each horse was immobilized in a fiberglass cast for 7 weeks, followed by cast removal and increasing amounts of exercise, beginning with hand-walking and ending with treadmill exercise. Lameness examination, arthrocentesis of both MPJ, single-emulsion radiographic examination, nuclear scintigraphic examination, grou...
Effects of ‘navicular’ shoeing on equine distal forelimb kinematics on different track surface. Orthopaedic shoeing applied for disorders such as navicular disease is mostly evaluated on hard track surfaces, but very often horses are ridden only on soft tracks. To compare the effects of normal shoes, eggbar shoes, and shoes with heel wedges (5 degrees) on the kinematics of the distal forelimb on hard and soft track surfaces, eleven sound Dutch Warmblood horses were led across three different tracks (an asphalt, a fibre/sand mix (= Agterberg), and a pure sand track) with three different shoe types (a normal shoe, an eggbar shoe, and a shoe with heel wedges). The hoof rotation and the maxi...
Forelimb tendon loading during jump landings and the influence of fence height. Lameness in athletic horses is often caused by forelimb tendon injuries, especially in the interosseus tendon (TI) and superficial digital flexor tendon (SDF), but also in the accessory ligament (AL) of the deep digital flexor tendon (DDF). In an attempt to explain the aetiology of these injuries, the present study investigated the loading of the tendons during landing after a jump. In jumping horses, the highest forces can be expected in the trailing limb during landing. Therefore, landing kinematics and ground reaction forces of the trailing forelimb were measured from 6 horses jumping singl...
Assessment of gait irregularities in the horse: eye vs. gait analysis. The purpose of this study was to verify the sensitivity of 2 gait analysis methods in detecting subtle lameness and to compare the results to the traditional orthopaedic evaluation. Twenty-two horses were evaluated (1) subjectively by 3 different experienced clinicians and (2) objectively with synchronised ground reaction force and accelerometric gait measurements on a treadmill. The horses were assigned for each of the 3 methods independently to one of 3 groups (GR): sound, lameness front limb, lameness hindlimb. Additionally, for each horse, the affected limb (AL) and degree of lameness (DL)...
Modification of a force plate system for equine gait analysis on hard road surfaces: a technical note. Studies on horseshoe materials have been limited to the analysis of kinematic data to determine slip times and distances, since equine force plate analysis is traditionally undertaken on a rubber-surfaced force plate. The purpose of this study was to modify a force plate for measuring ground reaction forces on a road surface and report preliminary data from the system. A steel-reinforced concrete top plate of 18 mm thickness and mass 23 kg, and a 12 mm thick top plate of 6 mm bituminous macadam wear coat (road surface) contained in a tray constructed of 2 mm thick steel, mass 21 kg, were const...
The effect of shoe material on the kinetics and kinematics of foot slip at impact on concrete. Previous studies on shoeing have demonstrated that shoe material alters the time taken from foot impact to the foot stopping sliding (slip time) and the distance slid. These are assumed to reflect differences in the craniocaudal ground reaction force (GRF) between the shoe and the ground during foot slip. This study tested the hypothesis that the slip time and distance are reflected in the resistance to slippage of the foot after impact. The forefeet of 8 horses were shod in horseshoes constructed of steel, plastic and rubber. Each horse was trotted for 8 placements per forefoot in each shoe t...
Sensitivity analysis and application to trotting of a noninvasive method to calculate flexor tendon forces in the equine forelimb. To test the sensitivity to measurement and modeling errors of a method for noninvasive calculation of flexor tendon forces in the equine forelimb and to calculate tendon forces for Dutch Warmblood horses during trotting. Methods: A normative set of kinematic and ground-reaction force (GRF) data obtained from horses during trotting in another study. Methods: Forces in the flexor tendons were calculated from the data set before and after addition of fixed relative and absolute errors. Amount of error was based on normal accuracy of the variables. A similar analysis was performed for a measure of...
Joint moments in the distal forelimbs of jumping horses during landing. Tendon injuries are an important problem in athletic horses and are probably caused by excessive loading of the tendons during demanding activities. As a first step towards understanding these injuries, the tendon loading was quantified during jump landings. Kinematics and ground reaction forces were collected from the leading and trailing forelimbs of 6 experienced jumping horses. Joint moments were calculated using inverse dynamic analysis. It was found that the variation of movement and loading patterns was small, both within and between horses. The peak flexor joint moments in the coffin a...
Effects of ground surface deformability, trimming, and shoeing on quasistatic hoof loading patterns in horses. To determine whether solar load distribution pattern on a solid nondeformable ground surface is the product of contact erosion and is the mirror image of load distribution on a deformable surface in horses. Methods: 30 clinically normal horses. Methods: Solar load distribution was compared among 25 clinically normal horses during quasistatic loading on a solid nondeformable surface and on a highly deformable surface. Changes in solar load distribution patterns were evaluated in 5 previously pasture-maintained horses housed on a flat nondeformable surface. Changes in solar load distribution cre...
Effect of walking velocity on ground reaction force variables in the hind limb of clinically normal horses. To measure the effect of subject velocity on hind limb ground reaction force variables at the walk and to use the data to predict the force variables at different walking velocities in horses. Methods: 5 clinically normal horses. Methods: Kinematic and force data were collected simultaneously. Each horse was led over a force plate at a range of walking velocities. Stance duration and force data were recorded for the right hind limb. To avoid the effect of horse size on the outcome variables, the 8 force variables were standardized to body mass and height at the shoulders. Velocity was standard...
The hindlimb in walking horses: 1. Kinematics and ground reaction forces. The objective was to study associations between kinematics and ground reaction forces in the hindlimb of walking horses. Video (60 Hz) and force (2000 Hz) data were gathered for 8 strides from each of 5 sound horses during the walk. Sagittal plane kinematics were measured concurrently with the vertical and longitudinal ground reaction forces. The hindlimb showed rapid loading and braking in the initial 10% stride. The stifle, tarsal and coffin joints flexed and the fetlock joint extended during this period of rapid loading. The vertical ground reaction force showed 2 peaks separated by a dip; ...
Evaluation of an in-shoe pressure measurement system in horses. To develop an objective, accurate method for quantifying forelimb ground reaction forces in horses by adapting a human in-shoe pressure measurement system and determine the reliability of the system for shod and unshod horses. Methods: 6 adult Thoroughbreds. Methods: Horses were instrumented with a human in-shoe pressure measurement system and evaluated at a trot (3 m/s) on a motorized treadmill. Maximum force, stance time, and peak contact area were evaluated for shod and unshod horses. Three trials were performed for shod and unshod horses, and differences in the measured values were examine...
Locomotor characteristics of horses with navicular disease. To determine whether force-plate evaluation of horses with navicular disease would reveal an abnormal gait that persists despite loss of sensation to the palmar foot region, which may predispose such horses to navicular disease. Methods: 17 clinically normal Thoroughbreds and 8 Thoroughbreds with navicular disease. Methods: Data on ground reaction forces were obtained in trotting horses, using a force plate. Force-time curve variables for clinically normal horses were derived from 4 points at the beginning and 4 points at the end of the vertical and craniocaudal horizontal plots. Principal com...
Use of an instrument sandwiched between the hoof and shoe to measure vertical ground reaction forces and three-dimensional acceleration at the walk, trot, and canter in horses. To develop an instrument that could be sandwiched between the hoof and shoe of horses and that would reliably measure vertical ground reaction forces and three-dimensional acceleration at the walk, trot, and canter. Methods: 5 clinically sound Thoroughbreds. Methods: The recording instrument (weight, 350 g) consisted of 2 metal plates, 2 bolts, 4 load cells, and 3 accelerometers. It was mounted to the hoof with a glue-on shoe and devised to support as much load exerted by a limb as possible. The load cells and accelerometers were wired to a 16-channel transmitter, and transmitted signals were ...
The forelimb in walking horses: 1. Kinematics and ground reaction forces. 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...
Kinematics and ground reaction forces in horses with superficial digital flexor tendinitis. 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...
The effects of a rider’s mass on ground reaction forces and fetlock kinematics at the trot. 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...
The effect of shoeing on kinetics and kinematics during the stance phase. The increasing range of of horseshoes and hoofpads makes it important to be able to evaluate their influence on performance and stress in the locomotor apparatus. The aim of this study was to describe the changes in ground reaction forces and locomotion pattern during the stance phase due to the application of a standard iron shoe. Six Swedish Warmblood horses were evaluated kinetically and kinematically before and after they were shod with an 8 mm iron shoe. Data were used to calculate ground reaction forces in the vertical and craniocaudal directions, point of application of the force, hoof ...
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...
Disease-specific changes in equine ground reaction force data documented by use of principal component analysis. To assess the force plate as a diagnostic aid in equine locomotor abnormalities, particularly for abnormalities such as navicular disease that do not have specific diagnostic criteria. Methods: 17 Thoroughbreds without observable locomotor abnormalities (group A), 6 Thoroughbreds with superficial digital flexor tendon injury (group B), and 8 Thoroughbreds with navicular disease (group C). Methods: Using a force plate, ground reaction force patterns were recorded at the trot. Peak limb vertical force and force/time curve parameters were derived from 4 identifiable points at the beginning and en...
Muscle-tendon stresses and elastic energy storage during locomotion in the horse. 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...
Net joint moments and powers in the equine forelimb during the stance phase of the trot. The objective of this study was to provide normative data describing the net joint moments and joint powers for the stance phase of the forelimb in trotting horses. Kinematic and force plate data, synchronised in time and space, were collected for the right forelimb of 6 Warmblood horses moving at a trot. The 3-D kinematic data were collapsed onto a sagittal plane, and were combined with the vertical and longitudinal ground reaction forces and with segment morphometric data to calculate net joint moments in the sagittal plane across the distal interphalangeal (coffin), metacarpophalangeal (fet...
Long-term consequences of experimental desmotomy of the accessory ligament of the deep digital flexor tendon in adult horses. To evaluate clinical and biomechanical consequences of desmotomy of the accessory ligament (AL) of the deep digital flexor tendon (DDFT) of equine forelimbs and determine whether this procedure is a viable treatment for chronic desmitis of the AL-DDFT. Methods: 6 adult Standardbred trotters. Methods: Biomechanical recordings obtained before and 6 months after desmotomy were compared. Walk and trot joint angles, ground reaction forces, peak joint moments, and tendon forces were assessed. Results: Within 10 days after surgery, all horses were sound at a trot. Swelling, increased carpal flexion i...
Model for injury to the foreleg of the Thoroughbred racehorse. A discussion is presented of contributing factors to the injury to the foreleg of the Thoroughbred racehorse. The critical part of the step is taken to be the first 10-20 ms after ground contact as the hoof slides forward and stops. Large nonaxial loads associated with the deceleration of the hoof are shown to arise. Results of accelerometer measurements on the hoof of a horse running at racing speed are presented as well as mechanical properties of the racing surface. The mechanical properties of the track surface, the type of shoe, and the degree of fatigue of the horse all work together to ...
Recovery of equine forelimb function after desmotomy of the accessory ligament of the deep digital flexor tendon. The recovery process of the equine locomotor system after desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT) was investigated by studying the movement patterns and joint moments in 6 horses before and 10 days and 6 months following surgery. Using a modified CODA-3 system the joint angles and angular velocities of the lower limb were assessed in the operated forelimb as before the operation. Simultaneously ground reaction forces were measured and joint moments calculated. At 10 days and 6 months after the operation the carpal joint started to bend earlier in the sta...
Ground reaction forces in horses, assessed from hoof wall deformation using artificial neural networks. An artificial neural network (ANN) was developed to investigate whether hoof wall deformation could be used to determine ground reaction forces (GRF) in horses. The ANN was taught this relationship under certain conditions and was able to generalise this knowledge to conditions for which it was not trained before. To acquire data to train and test the ANN, a horse was equipped with strain gauges attached to the dorsal, lateral and medial parts of the hoof to assess hoof wall deformation. A force plate was used to measure the GRFs. Both hoof wall deformation and GRF were recorded simultaneously...
Joint moments and power in equine gait: a preliminary study. A method is described for the estimation of joint moments of force and power in the equine forelimb using S-VHS video and force platform data. Video and force data were collected for 5 walking trials in a sound Dutch Warmblood horse. The sagittal plane positional and angular data were combined with the vertical and cranio-caudal ground reaction forces to calculate net joint moments of force in the sagittal plane across the carpal, fetlock and coffin joints during the stance phase of the forelimb. The mechanical power was calculated as the product of the netjoint moment and the joint's angular ...
Instrumentation and techniques in locomotion and lameness. The success of a clinical gait laboratory depends on choosing the right equipment, installing it correctly, running calibration checks, and having skilled technical and professional personnel. For kinematic analysis, videographic or optoelectronic systems are the method of choice, with 2-D data being adequate for the majority of equine evaluations. A force plate provides a precise description of the 3-D ground reaction force; transmission of the force through the body tissues is measured using strain gauges attached to the bones and tendons. Accelerometers bonded to the hoof wall provide infor...
Tendon strain in the forelimbs as a function of gait and ground characteristics and in vitro limb loading in ponies. Strains in the tendons of the m. flexor digitalis superficialis (superficial digital flexor, SDFT) and m. flexor digitalis profundus (deep digital flexor, DDFT) tendons, the accessory ligament of the deep digital flexor muscle (inferior check ligament, ICL) and the m. interosseus medius (suspensory ligament, SL) of 5 ponies were recorded at the walk and trot using mercury-in-silastic strain gauges (MISS), on a hard surface (brick pavement) and on sand. The horses were shod with normal, flat shoes. On pavement, strain in the SDFT, DDFT and SL increased significantly from the walk (2.19%, 1.15% ...
Influence of shoeing on ground reaction forces and tendon strains in the forelimbs of ponies. 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...