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Wennerstrand, J., Johnston, C., Roethlisberger-Holm, K., Erichsen, C., Eksell, P., & Drevemo, S. (2004). Kinematic evaluation of the back in the sport horse with back pain. Equine Vet J, 36(8), 707–711.
Abstract: REASONS FOR PERFORMING STUDY: Earlier studies have developed a clinical tool to evaluate objectively the function of the equine back. The ability to differentiate horses with back pain from asymptomatic, fully functioning horses using kinematic measures from this tool has not been evaluated. OBJECTIVES: To compare the kinematics of the back at walk and trot in riding horses with back dysfunction to the same parameters in asymptomatic sport horses. METHODS: The kinematics of the back in 12 horses with impaired performance and back pain were studied at walk and trot on a treadmill. Data were captured for 10 sees at 240 Hz. Range of movement (ROM) and intravertebral pattern symmetry of movement for flexion and extension (FE), lateral bending (LB) and axial rotation (AR) were derived from angular motion pattern data and the results compared to an earlier established database on asymptomatic riding horses. RESULTS: At walk, horses with back dysfunction had a ROM smaller for dorsoventral FE in the caudal thoracic region (T13 = 7.50 degrees, T17 = 7.71 degrees; P<0.05), greater for LB at T13 (8.13 degrees; P<0.001) and smaller for AR of the pelvis (10.97 degrees; P<0.05) compared to asymptomatic horses (FE-T13 = 8.28 degrees, FE-T17 = 8.49 degrees, LB-T13 = 6.34 degrees, AR-pelvis = 12.77 degrees). At trot, dysfunctional horses had a smaller (P<0.05) ROM for FE at the thoracic lumbar junction (T17 = 2.46 degrees, L1 = 2.60 degrees) compared to asymptomatic horses (FE-T17 = 3.07 degrees, FE-L1 = 3.12 degrees). CONCLUSIONS: The objective measurement technique can detect differences between back kinematics in riding horses with signs of back dysfunction and asymptomatic horses. The clinical manifestation of back pain results in diminished flexion/extension movement at or near the thoracic lumbar junction. However, before applying the method more extensively in practice it is necessary to evaluate it further, including measurements of patients whose diagnoses can be confirmed and long-term follow-ups of back patients after treatment. POTENTIAL RELEVANCE: Since the objective measurement technique can detect small movement differences in back kinematics, it should help to clinically describe and, importantly, objectively detect horses with back pain and dysfunction.
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Rhodin, M., Johnston, C., Holm, K. R., Wennerstrand, J., & Drevemo, S. (2005). The influence of head and neck position on kinematics of the back in riding horses at the walk and trot. Equine Vet J, 37(1), 7–11.
Abstract: REASONS FOR PERFORMING STUDY: A common opinion among riders and in the literature is that the positioning of the head and neck influences the back of the horse, but this has not yet been measured objectively. OBJECTIVES: To evaluate the effect of head and neck position on the kinematics of the back in riding horses. METHODS: Eight Warmblood riding horses in regular work were studied on a treadmill at walk and trot with the head and neck in 3 different predetermined positions achieved by side reins attached to the bit and to an anticast roller. The 3-dimensional movement of the thoracolumbar spine was measured from the position of skin-fixed markers recorded by infrared videocameras. RESULTS: Head and neck position influenced the movements of the back, especially at the walk. When the head was fixed in a high position at the walk, the flexion-extension movement and lateral bending of the lumbar back, as well as the axial rotation, were significantly reduced when compared to movements with the head free or in a low position. At walk, head and neck position also significantly influenced stride length, which was shortest with the head in a high position. At trot, the stride length was independent of head position. CONCLUSIONS: Restricting and restraining the position and movement of the head and neck alters the movement of the back and stride characteristics. With the head and neck in a high position stride length and flexion and extension of the caudal back were significantly reduced. POTENTIAL RELEVANCE: Use of side reins in training and rehabilitation programmes should be used with an understanding of the possible effects on the horse's back.
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Johnston, C., Holm, K. R., Erichsen, C., Eksell, P., & Drevemo, S. (2004). Kinematic evaluation of the back in fully functioning riding horses. Equine Vet J, 36(6), 495–498.
Abstract: REASONS FOR PERFORMING STUDY: Clinical history and examination are important features in diagnosis of equine back dysfunction. However, interpretation is subjective and therefore may vary substantially. OBJECTIVES: To establish a clinical tool to objectively evaluate the function of the equine back, in the form of a database on the kinematics of the back at the walk and trot in fully functioning riding horses. METHODS: Thirty-three fully functioning riding horses walked and trotted on a treadmill. Morphometrics and kinematics were tested for correlations to age, height, weight and stride length, and differences between gender (geldings and mares) and use (dressage and showjumping). RESULTS: A database for range of movement and symmetry of movement for extension and flexion, lateral bending, lateral excursion and axial rotation was presented. Symmetry values were very high for all variables. Significant differences were observed in use and gender. Age was negatively correlated to extension and flexion of the thoracolumbar junction. CONCLUSIONS: Interrelationships between use, gender and age to conformation and movement were established. POTENTIAL RELEVANCE: The database provides a basis for objective reference for diagnosis, therapy and rehabilitation of clinical cases of back dysfunction.
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Holmstrom, M., Fredricson, I., & Drevemo, S. (1995). Biokinematic effects of collection on the trotting gaits in the elite dressage horse. Equine Vet J, 27(4), 281–287.
Abstract: Trot in hand, working trot, collected trot, passage and piaffe of 6 Grand Prix dressage horses were recorded by high speed film (250 frames/s). Angular patterns and hoof trajectories of the left fore- and hindlimbs were analysed and presented as mean and standard deviation (s.d.) curves. Speed and stride length decreased and fore- and hind stance phase durations increased with collection resulting in no suspension in piaffe. The diagonal advanced placement was positive in all gaits except for piaffe. Most of the changes in forelimb angular patterns were effects of reduction in forelimb pendulation. The horses did not step under themselves more in collected trot, passage and piaffe than in trot in hand. The stifle and hock joints were more flexed at the start of the stance phase in piaffe and passage than in the other gaits. Flexion of the hock joint at the middle of the stance phase was largest in passage and piaffe. In spite of the limited number of horses the present study confirmed earlier observations of conformation and gaits in dressage horses. Hindlimb pendulation, femur and pelvis inclinations and elbow, carpal, stifle and hock joint angles seem to be the most significant angular measurements for dressage performance.
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Drevemo, S., Fredricson, I., Hjertén, G., & McMIKEN, D. (1987). Early development of gait asymmetries in trotting Standardbred colts. Equine. Vet. J., 19(3), 189–191.
Abstract: Summary Ten trotting Standardbred colts were recorded by high-speed cinematography at the ages of eight, 12 and 18 months. The horses were trotting on a treadmill operating at 4.0 m/secs. Five horses were subjected to a programme of intensified training from eight months of age, whereas the others were not trained and acted as controls. The films were analysed on a semi-automatic film-reading equipment and a number of variables used to demonstrate the gait symmetry were calculated and scaled by computer. Certain differences between left and right diagonal and contralateral pair of limbs, respectively, were noted, suggesting that laterality in horses may be inherited. The most pronounced systematic differences were found in 18-month old horses in the trained group. The results show the importance of careful gait examination and comprehensive coordination training at an early age.
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Holmstrom, M., & Drevemo, S. (1997). Effects of trot quality and collection on the angular velocity in the hindlimbs of riding horses. Equine Vet J Suppl, (23), 62–65.
Abstract: The angular velocities of the hindlimb angles of 14 horses, including 6 Grand Prix dressage horses, 4 horses judged as good at the trot and 4 horses judged as poor, were analysed. The horse material was the same as previously used by Holmstrom (1994) in studies on conformation and trotting gaits in the Swedish Warmblood riding horse. Four consecutive strides of each horse and the corresponding pace were analysed and mean velocity curves (Xh) for each angle were calculated. Before calculation the data were filtered forwards and backwards with a Butterworth third order filter with a cut off frequency of 60 Hz. During the last 60% of the stance phase there were differences between the horses judged as good and poor at the trot in all the analysed hindlimb angles except the femur inclination. The angular velocity in the hock joint, pelvis inclination and hindlimb pendulation was larger in the good horses. The angular velocity of the hindlimb pendulation decreased with collection in the Grand Prix horses. During parts of the stance phase, there was also a gradual decrease in the femur angular velocity from trot at hand to piaffe. In the hock joint, there was no difference in angular velocity between trot at hand and passage during the last 30%. The higher compression of the hock angle and pelvic angle to the horizontal plane probably reflects a higher compression of the whole hindlimb. It probably contributes to the greater springiness in the movements of good young horses and Grand Prix dressage horses. The results from the present study confirmed the importance of storing elastic strain energy for the quality of the dressage horse gaits.
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