bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transection of the sciatic nerve and reinnervation in adult rats: muscle and endplate morphology
Authors: IJKEMA‐PAASSEN J. , MEEK M. F. , GRAMSBERGEN A. 
Published: June 2010

SummaryThe functional recovery after peripheral nerve lesions is generally poor. We studied whether changes in muscles after reinnervation might explain such disappointing results. The functional recovery after peripheral nerve lesions is generally poor. Changes in muscle morphology and neuromuscular innervation might partly explain this lack of compensation. In order to test this hypothesis, we studied muscular differentiation in the soleus, gastrocnemius and tibialis anterior muscles at 7, 15 and 21 weeks after a sciatic nerve lesion in adult rats.In the gastrocnemius and tibialis muscles the percentages of type II muscles fibres were decreased at 7 and 15 weeks but at 21 weeks they again approached normal values. The soleus muscle, however, was permanently decreased in size and this muscle, in contrast to the normal soleus muscle, contained mainly type II fibres. The morphology of the endplates showed distinct stages of degeneration and reinnervation. Two weeks after denervation, in rats in which reinnervation was prevented, all 3 muscles contained considerable numbers of morphologically abnormal endplates and, after 7 weeks, no endplates were detected. During reinnervation, endplates showing signs of acetylcholinesterase activity were observed in all 3 muscles from 7 weeks. At later ages a shift towards morphologically normal endplates occurred, but complete recovery was not observed. Endplates in all 3 muscles were polyneurally innervated at 7 weeks. Although these percentages decreased over age, polyneural innervation was still present at 21 weeks.We conclude that the changes in the distribution of fibre types, abnormal endplate morphology and polyneural innervation may in part explain the poor functional recovery after peripheral nerve lesions.
In vivo and in vitro heel expansion in relation to shoeing and frog pressure
Authors: ROEPSTORFF L. , JOHNSTON C. , DREVEMO S. 
Published: June 2010

SummaryThe objective of this study was to validate a simple method to measure the mediolateral expansion of the heels and to apply this method in an in vivo experiment. It was also the aim to quantify the mediolateral expansion in different areas of the heel using an in vitro model.In the in vitro study, 5 right and 5 left distal forelimb specimens from 5 Standardbreds were mounted vertically in a custom‐made compressive test machine. The heel expansion was measured using optical kinematic analysis and a potentiometer system. Specimens were tested unshod, with frog pressure and with the weightbearing rim raised. In the in vivo study, a potentiometer system was fitted to the left forelimb of 5 Standardbred trotters. Measurements were performed with the horses at hand, in walk and in trot. They were tested unshod, shod with a standard 8 mm iron shoe and finally with a shoe combined with an inflatable hoof‐cushion. The results showed a good correlation between the 2 measurement systems (r = 0.98).This study describes the effect of different frog pressures on heel movement. Increased pressure on the frog and the sole increased heel expansion, but some heel expansion still occurred when the frog and sole were unsupported. The study supports, therefore, both the depression and the pressure theory. The significance of these results is the manipulation of heel movement as affected by farrier techniques and its possible relationship to health of the hoof. Further studies are needed to apply this knowledge correctly to farrier practice.
Effects of heel and toe elevation upon the digital joint angles in the standing horse
Authors: CREVIER‐DENOIX N. , ROOSEN C. , DARDILLAT C. , POURCELOT P. , JERBI H. , SANAA M. , DENOIX J.‐M. 
Published: June 2010

SummaryFive sound mature horses, age 8‐14 years, with toe angles 45.5‐55.0° were placed on a specially designed platform with only the left forelimb weightbearing, which allowed the successive production of 7 different conditions of foot orientation: neutral position (N), 5, 10, 15° heel (H5, H10, H15) and toe (T5, T10, T15) elevation, performed according to 2 different sequences. For each condition, 2 lateromedial radiographs were taken to evaluate the metacarpophalangeal joint (MPJ) and both interphalangeal joint (PIPJ and DIPJ) angles, respectively. In addition, two‐dimensional (2‐D) kinematic recordings, using reflective skin markers placed laterally on the left forelimb joints, were performed. The value of each joint angle (JA) and its angular variation to N (AV) were considered for statistical analysis.For all JA and their AV determined radiographically, the condition effect was significant and the sequence did not influence the differences between conditions. The relationships between the JA and the conditions (in the sequence: T15, T10, T5, N, H5, H10, H15) were overall linear for the 3 joints. The maximal range T15‐H15 was ± mean s.d. 6.9 ± 2.0 for MPJ (dorsal angle decrease), 7.3 ± 1.0° and 29.5 ± 1.8 for PIPJ and DIPJ (palmar angle decrease), respectively. Contrary to JA and in spite of large variations in hoof conformation, AV did not show any significant horse effect.Wide differences were observed between the digital JA measured radiographically and from kinematics, which could be related to cutaneous displacement. Heel elevation induced elbow flexion, whereas a slight extension was observed with toe elevation. These movements, even slight (mean elbow angle amplitude: 3.6 ± 1.3), may have consequences upon flexor tendon tension.
Three‐dimensional kinematics of the proximal interphalangeal joint: effects of raising the heels or the toe
Authors: DEGUEURCE C. , CHATEAU H. , JERBI H. , CREVIER‐DENOIX N. , POURCELOT P. , AUDIGIÉ F. , PASQUI‐BOUTARD V. , GEIGER D. , DENOIX J.‐M. 
Published: June 2010

SummaryThe proximal interphalangeal joint (PIPJ) has always been considered as a low‐motion joint with an almost constant angle during loading of the limb. Until very recently, its motion was not taken into account in kinematic studiesin vivo. Recentin vivo studies yielded surprisingly high rangesof motion in this joint. The aim of this study was to measure, in terms of the 3 possible rotations (flexion/extension, collateromotion and axial rotation), the movements of the PIPJin vitroduring limb loading in a neutral position (500‐6000 N) and after the addition of heel and toe wedges (6° and 12°). The joint coordinate system, as it was recently described for use in the horse, was used to compute the 3 components of rotation.With the hoof in neutral position, low‐amplitude flexion movements (7.9°) were observed. They were not associated with collateromotion or axial rotation. The flexion of the joint increased exponentially with load suggesting that, during the midstance phase, heavy loads are necessary to evoke substantial flexion. Raising the heels induced an early flexion of the joint with an increase of its total amplitude. Raising the toe produced an extension at 500 N, beyond which the amount of flexion was reduced.These results show that PIPJ flexion/extension duringin vitroloading remains substantially smaller than suggested byin vivostudies based on skin markers. Raising the toe or heel directly affects the behaviour of this joint, but does not induce motion outside the sagittal plane. Hoof wedges are commonly used in clinical practice for purposes other than affecting PIPJ motion. In these cases, their biomechanical effects on this joint should be taken into account.
Electromyographic and kinematic indicators of fatigue in horses: a pilot study
Authors: COLBORNE G. R. , BIRTLES D. M. , CACCHIONE I. C. 
Published: June 2010

SummaryMuscle fatigue can be quantified using Fourier analysis of the recorded EMG signal. Median frequency is the frequency at which the Fourier profile is bisected, and this measure typically shifts to smaller values during fatigue. This technique was combined with kinematic analysis to describe the time course of fatigue in horses galloping on an inclined treadmill. It was hypothesised that EMG median frequency would decrease in tandem with changes in kinematic variables through the exercise test. Three fit Thoroughbred horses had retroreflective markers placed on their hooves and withers. Surface electrodes were attached to the skin over the forelimb deltoid muscle. After warm‐up at walk and trot, each horse galloped at 110% VO2max on a treadmill inclined to 7.5% until fatigue onset. Kinematic data were recorded at 200 Hz for 5 s at 30s intervals, and raw EMG data were recorded at 1024 Hz for 3 s at 15 s intervals. Fatigue onset was the point in time when the horse could not keep up with the treadmill speed with minimal encouragement. One horse performed the entire exercise test on the same lead, while the other 2 horses changed leads periodically, interrupting the changes in both the EMG and kinematic measurements. Overall, through the course of the trials, mean stride length increased by 0.34 m and stride duration increased by 0.03 s. Vertical excursion of the trunk marker increased by 0.03 m. For the horse that did not change lead, median frequency of the EMG signal decreased by 36%. In the other 2 horses, lead changes were interspersed between smaller decreases in median frequency, whereupon median frequency recovered to starting levels immediately following a lead change. The median frequency decreased by 12‐20% between lead changes. Kinematic changes are more global indictors of fatigue, while the EMG indicators are dependent upon lead changes.
Locomotion evaluation for racing in Thoroughbreds
Authors: BARREY E. , EVANS S. E. , EVANS D. L. , CURTIS R. A. , QUINTON R. , ROSE R. J. 
Published: June 2010

SummaryThe potential racing and locomotory profile of a Thoroughbred yearling should be taken into account for its training programme and racing career. A gait test has been designed to assist the trainer in this task. The aim of this study was to investigate the temporal and kinetic locomotory variables of Thoroughbreds at the gallop, in relationship to their racing ability. Thirty Thoroughbred horses in race training were tested at maximal speed during a training session. The training exercise consisted of a warming‐up session at trot and canter for 10 min followed by a gallop session at increasing speed on a dirt track 1942 m long. The maximal speed was measured for the last 800 m before the finishing post. An accelerometric device attached to the girth provided quantitative information about the kinetic and temporal variables of the gallop such as: stride length (SL), stride frequency (SF), times elapsed between each hoof midstance phase (HIND, DIAGO, FORE), regularity of the strides (REG), mean vector of propulsion (VPROP), energy of propulsion (EPROP) and energy of loading (ELOAD). The performance records (number of wins, placings and average earning/start [PERF]) were used to analyse the relationship with the gait measurements. The mean maximum speed was 15.26 m/s. Several locomotory variables were significantly (P<0.05) correlated to the gallop speed: SL (0.90), SF (0.75), DIAGO (0.42), REG (‐0.47), VPROP (0.52), ELOAD (0.56) and EPROP (0.65). There were significant correlations between PERF and the following gait variables: REG (0.79), DIAGO (0.43), SF (0.42), SL (‐0.32) and ELOAD (‐0.40). The horses that won short distance races (<1400 m) had a larger relative ground contact duration and higher stride frequency than horses that won in longer distance races. The gait test was easy to perform and provided useful locomotory variables that may be used to evaluate the racing ability of the Thoroughbreds in training.
Changes due to age in the kinematics of trotting Andalusian foals
Authors: CANO M. R. , MIRO F. , MONTERDE J. G. , DIZ A. , MARTIN J. , GALISTEO A. M. 
Published: June 2010

SummaryThe purpose of this study was to evaluate the effect of growth on biokinematic characteristics at the trot in a group of 9 Andalusian foals from age 12 to 36 months in order to identify which stride variables change or remain invariable. Biokinematic analysis was performed by using a computer‐assisted videography system (25 Hz frame rate). An increase in stride length as well as the fore‐ and hindlimb stride duration was found. A tendency to increase flexion of the shoulder, elbow and carpal joints was observed while the forelimb fetlock increased its maximal extension. In the hindlimb, most of the differences were exhibited by the hip and stifle joints, which showed a tendency to a lesser flexion with age. However, at landing the extension was bigger. The hindlimb fetlock extended more in older foals, whereas flexion decreased. Significant differences in the maximal extension and flexion instants in the forelimb joints were not detected (except in the elbow joint). The same was found in the angular range of motion (ARM) of the scapula inclination and the shoulder and forelimb fetlock joints. Differences in retraction‐protraction angles in both the fore‐and hindlimbs were very slight, and ARM values for these parameters were similar in all age groups.
Body centre of mass movement in the lame horse
Authors: BUCHNER H. H. F. , OBERMÜLLER S. , SCHEIDL M. 
Published: June 2010

SummaryThe body centre of mass (BCM) is a key factor in the analysis of equine gait, as its position and movement determines the distribution and magnitude of loads on the limbs. Changes in the BCM movement are proposed to be important factors in the lameness management of horses. In this study, changes in the position and the 3‐dimensional (3‐D) movement of the BCM in horses with induced forelimb lameness were studied using a kinematic, segmental method.The kinematics of 30 markers representing 20 body segments were recorded in 12 horses while trotting (3.9 m/s) on a treadmill using a high speed video system. A transient lameness model, evoking pressure‐induced pain on the hoof sole, was used to induce 2 degrees of forelimb lameness. Based on segmental inertial data from Buchneret al. (1997) 3‐D segmental centres of mass as well as the BCM were calculated. The changes in BCM movement due to lameness and the influence of selected segments on the total centre of mass were analysed.During moderate forelimb lameness, vertical displacement of the BCM showed a 34% reduced amplitude during the stance phase of the lame limb and a 9% increased amplitude during the stance phase of the sound forelimb. In the sagittal direction, the BCM during midstance moved 9 mm backwards during the stance phase of the lame forelimb. Transversal movements showed a slight, but significant shift of the BCM to the side of the sound forelimb. Head/neck segment movement changed in a sagittal as well as in a vertical direction, but only a small amount, insufficient for considerable BCM position changes.The results show a similar pattern of BCM and trunk movement and only small adaptations of BCM position due to lameness. The influence of the sagittal position of the BCM has to be seen as a minor factor in lameness management compared to the dynamic influences of a changed vertical BCM movement and the moment caused by the typical head and neck movement.
Assessment of gait irregularities in the horse: eye vs. gait analysis
Authors: WEISHAUPT M. A. , WIESTNER T. , HOGG H. P. , JORDAN P. , AUER J. A. , BARREY E. 
Published: June 2010

SummaryThe 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) were defined. The accordance between the 3 assessment methods for the categorical variables was tested with a Spearman correlation analysis. The relationship between vertical ground reaction forces and dorsoventral as well as mediolateral accelerations were studied using a Pearson correlation matrix.Significant correlation was found between the clinical GR and GR based on force (r = 0.51, P<0.05) and acceleration data (r = 0.47, P<0.05), respectively, and between AL based on clinical and ground reaction force (r = 0.65, P<0.05) assessment. No significant correlation was found, neither for GR between the 2 measuring methods, nor for DL between the 3 assessment methods. The Pearson correlation matrix revealed significant correlations between peak vertical forces and dorsoventral acceleration in the hindlimbs. We conclude that the measurement of kinetic parameters represents a helpful complementary tool in the assessment of subtle gait alterations. However, this information needs to be interpreted carefully and always related to the clinical observation.
Three‐dimensional kinematics of the equine spine during canter
Authors: FABER M. , JOHNSTON C. , SCHAMHARDT H. C. , VAN WEEREN P. R. , ROEPSTORFF L. , BARNEVELD A. 
Published: June 2010

SummaryMost research on equine kinematics has previously been performed in the walking and/or trotting animal. This is also true for the few studies on the kinematics of the equine back. These studies have, for the major part, focused on the flexion‐extension movement in the sagittal plane. However, vertebrae can rotate in 3 dimensions. This study was designed to determine all 3 rotations in various segments of the vertebral column of a cantering horse. Five Dutch Warmblood horses were measured during treadmill canter (7.3 m/s). Steinmann pins were inserted into the dorsal spinous processes of 8 thoracic (T), lumbar (L) and sacral (S) vertebrae and into bothtubera coxae.A set of 4 markers was rigidly attached to each pin. The marker data were used to calculate a rotation matrix that was subsequently decomposed into 3 orthogonal rotations (flexion/extension [FE]; lateral bending [LB] and axial rotation [AR]). For the 3 rotations the variability between the horses was low for FE, slightly larger for AR and largest for LB. The maximal range of motion (mean ± s.d.) for FE, LB and AR was 15.8 ± 1.3°, 5.2 ± 0.7° and 7.8 ± 1.2°, respectively. With respect to relative angles, the largest FE motion was found between L5 and S3 with values for the range of motion up to 8.6°. Simultaneous rotation of successive vertebrae was observed particularly during the single support and suspension phases in the stride cycle, which increases spinal stability. For all rotations, a close correlation was observed between the timing of the vertebral rotations and the pro‐ and retraction of the limbs.
Effects of treadmill speed on the mechanics of the back in the trotting saddlehorse
Authors: ROBERT C. , AUDIGIÉ F. , VALETTE J. P. , POURCELOT P. , DENOIX J.‐M. 
Published: June 2010

SummarySpeed related changes in trunk mechanics have not yet been investigated, although high‐speed training is currently used in the horse. To evaluate the effects of speed on back kinematics and trunk muscles activity, 4 saddle horses were recorded while trotting on a horizontal treadmill at speeds ranging from 3.5 to 6 m/s. The 3‐dimensional (3‐D) trajectories of skin markers on the left side of the horse and the dorsal midline of the trunk were established. Electrical activity was simultaneously obtained from thelongissimus dorsi(LD) andrectus abdominis(RA) muscles using surface electrodes. Ten consecutive strides were analysed for each horse at each of the 5 velocity steps. Electromyographic and kinematic data were time‐standardised to the duration of the stride cycle and compared using an analysis of variance. The back extended during the first part of each diagonal stance phase when the RA was active and the back flexed during the second part of each diagonal stance phase when the LD was active. The onset and end of muscle activity came earlier in the stride cycle and muscle activity intensity increased when speed increased. The amplitude of vertical movement of the trunk and the maximal angles of flexion decreased with increasing speed, whereas the extension angles remained unchanged. This resulted in a decreased range of back flexion‐extension. This study confirms that the primary role of trunk muscles is to control the stiffness of the back rather than to induce movements. Understanding the effects of speed on the back of healthy horses is a prerequisite for the prevention and treatment of back pathology.
Segmentalin vivovertebral kinematics at the walk, trot and canter: a preliminary study
Authors: HAUSSLER K. K. , BERTRAM J. E. A. , GELLMAN K. , HERMANSON J. W. 
Published: June 2010

SummaryUnderstanding the pathophysiology of equine back problems, for clinical evaluation, treatment or injury prevention, requires understanding of the normal 3‐dimensional motion characteristics of the vertebral column. Recent studies have investigated regional vertebral kinematics; however, there are no reported measures of directin vivosegmental vertebral kinematics in exercising horses. Relative movements between 2 adjacent vertebrae were recorded for 3 horses that were clinically sound and did not have a known history of a back problem. A transducer consisting of 2 fixtures and an array of liquid metal strain gauges (LMSGs) was used to measure 3‐dimensional segmental vertebral motion. The transducer was attached directly to Steinmann pins implanted in the dorsal spinous processes of adjacent vertebrae in 3 vertebral regions: thoracic (T14 to T16), lumbar (L1 to L3) and lumbosacral (L6 to S2). Rotational displacements between adjacent vertebrae were calculated from the differential outputs of the LMSG array during walk, trot and canter on a treadmill. Peak magnitudes of dorsoventral flexion, lateral bending and axial rotation were recorded continuously for each stride. The largest motion of the 3 instrumented vertebral segments was at the lumbosacral junction. In general, the greatest magnitude of segmental vertebral motion occurred during the canter and the least during the trot. The dynamic and continuous measure of 3‐dimensionalin vivosegmental vertebral motion provides an important new perspective for evaluating vertebral motion and back problems in horses.
Evaluation of the EMG activity of the long back muscle during induced back movements at stance
Authors: PEHAM C. , FREY A. , LICKA T. , SCHEIDL M. 
Published: June 2010

SummaryIn this study we investigated the activity of the main back muscle (Musculus longissimus) by surface electromyography (EMG) during induced extension and lateral flexion at stance. Measurements were taken of 15 horses (age 5‐20 years, 450‐700 kg bwt) without signs of back pain. Reflecting markers were placed on the head, spinous processes of T5, T12, T16, L3 and on 2 of the sacral bones. The surface EMG electrodes were situated on theMusculus longissimuson both sides of the dorsal spinous processes of T12, T16 and L3.In all horses and all movements (extension, lateral flexion to the left and right), the EMG on both sides of the dorsal spinous process of T12 had the highest, and the EMG on both sides of the spinous process of L3, the lowest amplitude (30% of T12). At T16 the amplitude of the EMG signal was 60% of that at T12. There was no time shift between the EMG signals at the different locations (T12, T16, L3). There was a very high correlation between motion and amplitude of the EMG signal of extension, with correlation coefficients of 0.78 at L3, 0.80 at T16 and 0.75 at T12. The correlation of the lateral flexion between amplitude of the EMG and motion was lower, with 0.38 at L3, 0.43 at T16 and 0.39 at T12. This investigation showed that the EMG of theMusculus longissimusduring spinal reflexes should be derived on both sides of T12, because this is important for the clinical use of surface EMG.