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- Author or Editor: Ab Barneveld x
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Abstract
Objective—To determine the validity of using skin-fixated markers to assess kinematics of the thoracolumbar vertebral column in horses.
Animals—5 Dutch Warmblood horses without abnormalities of the vertebral column.
Procedure—Kinematics of T6, T10, T13, T17, L1, L3, L5, S3, and both tuber coxae were determined by use of bone-fixated and skin-fixated markers. Threedimensional coordinate data were collected while horses were walking and trotting on a treadmill. Angular motion patterns were calculated and compared on the basis of 2-dimensional analysis of data from skin-fixated markers and 3-dimensional analysis of data from bone-fixated markers.
Results—Flexion-extension of thoracolumbar vertebrae and axial rotation of the sacrum were satisfactorily determined at both the walk and trot, using skinfixated markers. Data from skin-fixated markers were accurate for determining lateral bending at the walk in the midthoracic and lower lumbar portion of the vertebral column only. However, at the trot, data from skin-fixated markers were valid for determining lateral bending for all thoracolumbar vertebrae.
Conclusions and Clinical Relevance—Caution should be taken when interpreting data obtained by use of skin-fixated markers on lateral bending motions during the walk in horses. For determination of other rotations at the walk and all rotations at the trot, use of skin-fixated markers allows valid calculations of kinematics of the vertebral column. Understanding to what extent movements of skin-fixated markers reflect true vertebral motion is a compulsory step in developing noninvasive methods for diagnosing abnormalities of the vertebral column and related musculature in horses. (Am J Vet Res 2001;62:301–306)
Abstract
Objective—To investigate the effects of early training for jumping by comparing the jumping technique of horses that had received early training with that of horses raised conventionally.
Animals—40 Dutch Warmblood horses.
Procedure—The horses were analyzed kinematically during free jumping at 6 months of age. Subsequently, they were allocated into a control group that was raised conventionally and an experimental group that received 30 months of early training starting at 6 months of age. At 4 years of age, after a period of rest in pasture and a short period of training with a rider, both groups were analyzed kinematically during free jumping. Subsequently, both groups started a 1-year intensive training for jumping, and at 5 years of age, they were again analyzed kinematically during free jumping. In addition, the horses competed in a puissance competition to test maximal performance.
Results—Whereas there were no differences in jumping technique between experimental and control horses at 6 months of age, at 4 years, the experimental horses jumped in a more effective manner than the control horses; they raised their center of gravity less yet cleared more fences successfully than the control horses. However, at 5 years of age, these differences were not detected. Furthermore, the experimental horses did not perform better than the control horses in the puissance competition.
Conclusions and Clinical Relevance—Specific training for jumping of horses at an early age is unnecessary because the effects on jumping technique and jumping capacity are not permanent. (Am J Vet Res 2005;66:418–424)
Abstract
Objective—To quantify variation in the jumping technique within and among young horses with little jumping experience, establish relationships between kinetic and kinematic variables, and identify a limited set of variables characteristic for detecting differences in jumping performance among horses.
Animals—Fifteen 4-year-old Dutch Warmblood horses.
Procedure—The horses were raised under standardized conditions and trained in accordance with a fixed protocol for a short period. Subsequently, horses were analyzed kinematically during free jumping over a fence with a height of 1.05 m.
Results—Within-horse variation in all variables that quantified jumping technique was smaller than variation among horses. However, some horses had less variation than others. Height of the center of gravity (CG) at the apex of the jump ranged from 1.80 to 2.01 m among horses; this variation could be explained by the variation in vertical velocity of the CG at takeoff ( r, 0.78). Horses that had higher vertical velocity at takeoff left the ground and landed again farther from the fence, had shorter push-off phases for the forelimbs and hind limbs, and generated greater vertical acceleration of the CG primarily during the hind limb pushoff. However, all horses cleared the fence successfully, independent of jumping technique.
Conclusions and Clinical Relevance—Each horse had its own jumping technique. Differences among techniques were characterized by variations in the vertical velocity of the CG at takeoff. It must be determined whether jumping performance later in life can be predicted from observing free jumps of young horses. ( Am J Vet Res 2004;65:938–944)
Abstract
Objective—To determine whether differences in jumping technique among horses are consistent at various ages.
Animals—12 Dutch Warmblood horses.
Procedure—Kinematics were recorded during free jumps of horses when they were 6 months old (ie, no jumping experience) and 4 years old (ie, the horses had started their training period to become show jumpers). Mean ± SD height of the horses was 1.40 ± 0.04 m at 6 months of age and 1.70 ± 0.05 m at 4 years of age.
Results—Strong correlations were found between values from 6-month-old foals and 4-year-old horses for variables such as peak vertical acceleration generated by the hind limbs ( r, 0.91), peak rate of change of effective energy generated by the hind limbs ( r, 0.71), vertical velocity at takeoff ( r, 0.65), vertical displacement of the center of gravity during the airborne phase ( r, 0.81), and duration of the airborne phase ( r, 0.70).
Conclusions and Clinical Relevance—Although there are substantial anatomic and behavioral changes during the growing period, certain characteristics of jumping technique observed in naïve 4-year-olds are already detectable when those horses are foals. ( Am J Vet Res 2004;65:945–950)
Abstract
Objective—To determine kinematic movements of the vertebral column of horses during normal locomotion.
Animals—5 Dutch Warmblood horses without apparent lameness or problems associated with the vertebral column.
Procedure—Kinematics of 8 vertebrae (T6, T10, T13, T17, L1, L3, L5, and S3) and both tuber coxae were determined, using bone-fixated markers. Horses were recorded while walking on a treadmill at a constant speed of 1.6 m/s.
Results—Flexion-extension was characterized by 2 periods of extension and flexion during 1 stride cycle, whereas lateral bending and axial rotation were characterized by 1 peak and 1 trough. The range of motion for flexion-extension was fairly constant for vertebrae caudal to T10 (approximately 7°). For lateral bending, the cranial thoracic vertebrae and segments in the pelvic region had the maximal amount of motion, with values of up to 5.6°. For vertebrae between T17 and L5, the amount of lateral bending decreased to < 4°. The amount of axial rotation increased gradually from 4° for T6 to 13° for the tuber coxae.
Conclusions—This direct measurement method provides 3-dimensional kinematic data for flexion-extension, lateral bending, and axial rotation of the thoracolumbar portion of the vertebral column of horses walking on a treadmill. Regional differences were observed in the magnitude and pattern of the rotations. Understanding of the normal kinematics of the vertebral column in healthy horses is a prerequisite for a better understanding of abnormal function. (Am J Vet Res 2000;61:399–406)
Abstract
Objective—To determine movements of the vertebral column of horses during normal locomotion.
Animals—5 young Dutch Warmblood horses that did not have signs of back problems or lameness.
Procedure—Kinematics of 8 vertebrae (T6, T10, T13, T17, L1, L3, L5, and S3) and both tuber coxae were determined, using bone-fixated markers. Measurements were recorded when the horses were trotting on a treadmill at a constant speed of 4.0 m/s.
Results—Flexion-extension and axial rotation were characterized by a double sinusoidal pattern of motion during 1 stride cycle, whereas lateral bending was characterized by 1 peak and 1 trough. Ranges of motion for all vertebrae were: flexion-extension, 2.8o to 4.9o; lateral bending, 1.9° to 3.6°; axial rotation, 4.6° to 5.8°, except for T10 and T13, where the amount of axial rotation decreased to 3.1° and 3.3°, respectively.
Conclusion and Clinical Relevance—During locomotion, 3 types of rotations are evident in the thoracolumbar vertebrae. Regional differences are observed in the shape and timing of the rotations. These differences are related to actions of the limbs. The method described here for direct measurement of vertebral column motion provides insights into the complex movements of the thoracolumbar portion of the vertebral column in trotting horses. Information on normal kinematics is a prerequisite for a better understanding of abnormal function of the vertebral column in horses. (Am J Vet Res 2001;62:757–764)
Abstract
Objective—To determine the speed of sound (SOS) in equine articular cartilage and investigate the influence of age, site in the joint, and cartilage degeneration on the SOS.
Sample Population—Cartilage samples from 38 metacarpophalangeal joints of 38 horses (age range, 5 months to 22 years).
Procedure—Osteochondral plugs were collected from 2 articular sites of the proximal phalanx after the degenerative state was characterized by use of the cartilage degeneration index (CDI) technique. The SOS was calculated (ratio of needle-probe cartilage thickness to time of flight of the ultrasound pulse), and relationships between SOS value and age, site, and cartilage degeneration were evaluated. An analytical model of cartilage indentation was used to evaluate the effect of variation in true SOS on the determination of cartilage thickness and dynamic modulus with the ultrasound indentation technique.
Results—The mean SOS for all samples was 1,696 ± 126 m/s. Age, site, and cartilage degeneration had no significant influence on the SOS in cartilage. The analytical model revealed that use of the mean SOS of 1,696 m/s was associated with maximum errors of 17.5% on cartilage thickness and 7.0% on dynamic modulus in an SOS range that covered 95% of the individual measurements.
Conclusions and Clinical Relevance—In equine articular cartilage, use of mean SOS of 1,696 m/s in ultrasound indentation measurements introduces some inaccuracy on cartilage thickness determinations, but the dynamic modulus of cartilage can be estimated with acceptable accuracy in horses regardless of age, site in the joint, or stage of cartilage degeneration. (Am J Vet Res 2005;66:1175–1180)
