摘要:

SummaryThe aim of this study was to give riding teachers, physiotherapists and research workers a better understanding of the three‐dimensional movement of the horse's saddle. The gaits of 7 horses were recorded on the treadmill by an accelerometric crown fixed to the front of a saddle. After a Fourier analysis of the signal, noise was eliminated; after a double integration data were obtained describing the crown's movement, assuming that after each stride the saddle returns to the original place. The movement was visualised in two and three dimensions. The walk showed more twisting motions, whereas the trot had more rolling, longitudinal and lateral movement. The canter showed the highest amplitude of motion, with a strong pitching rotation but little twisting. The pitching movement was the most important type of rotation for the three gaits. The speed at the canter did not influence the shape of the movement pattern

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1994.tb04872.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryCompressions of the hind limb in a horse trotting at 3.7 m/s were studied by use of high‐speed cinematography. It is concluded that distal loading, beginning at the hoof, resulted in a longer impact time and smaller impact forces compared to a theoretical stiff limb. Shortening of the hind limb during the stance occurs from hoof to stifle, while there is an elongation of the distance between the stifle and tuber coxa

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1994.tb04873.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe trotting gait of 4 approved Swedish Warmblood stallions with a mean gait score ≥8.67 (maximum score = 10) at official performance tests and 4 horses with poor gaits (mean gait score ≤6.5) was recorded by high speed film (250 frames/s). Angular patterns and hoof trajectories of the left fore and hind limbs were analysed and presented as mean and standard deviation curves. The good horses had longer stride duration (p<0.001) and larger positive diagonal advanced placement (p<0.01). The swing phase retraction in the forelimbs was longer in the good horses. The most important differences in the forelimb angular patterns were found in the elbow and carpal joint angles. They were considerably more flexed in the good horses at the beginning of the swing phase retraction. Larger decrease of the pelvis inclination, increase of the femur inclination and larger flexion of the hock and hind fetlock joints during the stance phase were correlated with high trot scores. This indicates that storage of elastic strain energy during the stance phase may be important for the elasticity, energy and propulsion in t

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1994.tb04874.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryTendons of 12 equine forelimbs were loaded until failure using a drawbench. Preceding the tensile test, the cross sectional area was measured at the narrowest site of the tendon. Small beads were sutured to the tendons, as markers for length change measurement from photographs. During loading, photographs were taken at about 3 Hz and the load was recorded. The maximal strain was calculated by means of linear regression of length‐time data and extrapolation to the instant of failure according to the force‐time curve. Total failure of the superficial and deep digital flexor tendons, the distal check ligament and the suspensory ligament occurred at a strain (± sd) of respectively 10.9 (± 1.4), 9.5 (± 1.5), 12.4 (± 1.0) and 11.6 (± 1.4) % and at a stress of respectively 116 (± 21), 133 (± 14), 86 (± 11) and 7

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1994.tb04875.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe mechanical and geometric properties of metacarpal bones of 41 Quarter Horse yearlings fed diets with different energy and phosphorus levels were tested and compared. A 2 times 3 factorial experiment was used to compare 2 energy sources and 3 levels of dietary phosphorus. The 2 energy sources were based either on alfalfa (2.65 Mcal digestible energy [DE]/kg dry matter [DM]feed) or on grain (3.09 Mcal DE/kg DM). In each diet type, the 3 phosphorus concentrations included: an unsupplemented, low phosphorus (LP) diet; a normal phosphorus (NP) diet supplemented to meet NRC (1978) requirements for weanling foals; and a high phosphorus (HP) diet supplemented to supply 150% of 1978 NRC phosphorus requirements. At the completion of the feeding trial, the yearling horses were destroyed and the metacarpal bones recovered. The left metacarpus was serially sectioned at 0.5 cm thicknesses with a band saw and a section was sampled for histology and measurement of geometric properties including the rectangular moments of inertia (Ix, Iy), the products of inertia and principal moments of inertia (Ixx, Iyy). The moments of inertia were then recalculated to the change in orientation of the x‐y axes and symbolised Ix1and Iy1. Energy intakes were similar despite differences in energy content of the forage and grain diets. However, forage‐fed yearlings had lower (p<0.0589) breaking strengths (23.4 kilograms per square inch [ksi] than grain‐fed horses (25.4 ksi). The geometric properties between LP and NP groups did not differ. However, the geometric properties (Ix1, Ixx, Iyy) differed (p<0.05) between the HP groups and the LP and NP groups. Within the NP group, (Iyy) differed (p<0.038) between males and females. The right metacarpus, with both small metacarpal bones removed but with the periosteum intact, was loaded in a 4‐point bending until failure. The metacarpal bones were placed in a specially‐made Instron tester made so that the mid‐diaphyses were loaded. All bones failed in a single plane at right angles to the main axis of the bone. Seventeen of the 41 bones (41.5%) fractured through the nutrient foramen. The mechanical properties of males and females did not differ except in the NP group wherein stiffness of the metacarpal bone of females was lower (p<0.05). In the NP group, males were 14% heavier (p<0.0384) than females. Although most mechanical properties did not differ between the LP and NP groups, the HP group had a higher load at yield point (6397 N) than the LP group (5789 N). Phosphorus intakes, therefore, affect both mechanical strength and geometric properties of gro

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1994.tb04876.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummarySimultaneous recordings were made of retardatory‐propulsory horizontal (Fy) and vertical (Fz) ground reaction forces (GRF), and kinematics of the fetlock joint and the hoof‐sole with respect to the ground of the right forelimbs and hind limbs of 4 Dutch Warmbloods, at the walk and the trot. The impact oscillation visible in Fy and Fz is the same at the walk and trot, and differs between fore‐ and hind limbs. The angulation pattern of the fetlock joint does not follow the faster oscillations visible in the GRF. The change in the course of Fy and Fz in the final stage of ground contact is caused by onset of heel lif

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1994.tb04877.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryIn the present study, 3 horses trotted at a series of different speeds on a SätoTMtreadmill and a coir mat treadmill to determine the differences in ground reaction forces due to the surface of the treadmills. The horses were equipped with a force‐measuring horseshoe to quantify the ground reaction forces which were analysed with spectral analysis. Significant differences between the 2 treadmills were seen in frequency content of the power spectrum for the vertical force at the frequency interval 30–80 Hz and for the fore‐aft force at 30–40 Hz and 7

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1994.tb04878.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryMutual timing relationships between hoof and fetlock joint kinematics, and objective criteria for ground contact based on accelerometry and ground reaction force measurements, were obtained for the right forelimbs and hind limbs of 4 horses at the walk and trot. Initial ground contact can be determined from accelerometer data or force plate signals, but not with sufficient accuracy from kinematics only. Prior to initial ground contact the hoof is positioned with the heels lowered in 3 of 4 horses. The change to foot flat occurs within 9 ms and can be identified unequivocally, provided that the hoof is visible and the recording equipment is sufficiently fast. Assuming that the onset of the stance phase is known, the end of the stance phase can be determined within 10% stride duration from the time at which the fetlock joint angle is identical to that at initial ground contact. Another criterion is the time at which the metacarpus or metatarsus and the first phalanx are aligned.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1994.tb04879.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe sagittal plane kinematics of trunk, neck, and hind limb were analysed in a group of 15 elite show jumping horses during the push‐off of the hind limbs before jumping a 1.50 m upright fence. Similar movement patterns were observed in all horses. Ensemble averages of the kinematic variables of the group were calculated after spline smoothing and time‐normalisation with respect to the support phase. The final support phase of the hind limbs was symmetrical and had a duration of 221 ± 19 ms. During the first half of this period, the trunk rotated towards a more upright orientation and the height of the estimated centre of mass was decreased by about 0.05 m. These movements were accompanied by 25 degrees of hip extension and 40 degrees of flexion in the stifle and hock joints. These movements bring the hind limbs into a favourable, flexed position to produce mechanical power and transfer it to the trunk. Maximal flexion in the tarsal joint was reached at 98 ms after ground contact, followed by the stifle joint at 124 ms. After maximal flexion, the total extension movement of the tarsal and stifle joints was 45 and 22 degrees respectively. The extension of the hip continued until 152 ms after ground contact, and the angle remained stationary afterwards. The extension of the hind limb was accompanied by a large increase in horizontal and vertical velocity of the trunk, and a reversal of the rotation of the trunk. The average rate of mechanical power production during the entire push‐off, estimated from the change in kinetic and potential energy, was 59,000 W. By comparing total energy at the beginning and end of the support phase, it was concluded that most of the energy required to clear the fence was produced by the hind limbs during the final support phase, and that the previous actions of the forelimbs are merely bringing the horse into a good position for the final pu

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1994.tb04880.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY