| 1. |
- Andersson, Lisa, et al.
(författare)
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Mutations in DMRT3 affect locomotion in horses and spinal circuit function in mice
- 2012
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 488:7413, s. 642-646
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Tidskriftsartikel (refereegranskat)abstract
- Locomotion in mammals relies on a central pattern-generating circuitry of spinal interneurons established during development that coordinates limb movement(1). These networks produce left-right alternation of limbs as well as coordinated activation of flexor and extensor muscles(2). Here we show that a premature stop codon in the DMRT3 gene has a major effect on the pattern of locomotion in horses. The mutation is permissive for the ability to perform alternate gaits and has a favourable effect on harness racing performance. Examination of wild-type and Dmrt3-null mice demonstrates that Dmrt3 is expressed in the dI6 subdivision of spinal cord neurons, takes part in neuronal specification within this subdivision, and is critical for the normal development of a coordinated locomotor network controlling limb movements. Our discovery positions Dmrt3 in a pivotal role for configuring the spinal circuits controlling stride in vertebrates. The DMRT3 mutation has had a major effect on the diversification of the domestic horse, as the altered gait characteristics of a number of breeds apparently require this mutation.
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| 2. |
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| 3. |
- Bergström, Annika, et al.
(författare)
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Long-Term Effect of Intra-Articular Adipose-Derived Stromal Vascular Fraction and Platelet-Rich Plasma in Dogs with Elbow Joint Disease-A Pilot Study
- 2024
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Ingår i: Veterinary Sciences. - 2306-7381. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Elbow osteoarthritis (OA) is a common cause of pain and lameness in dogs, often resulting from the developmental disorder elbow dysplasia. Currently, there is no effective treatment or cure for this disease. This study aimed to evaluate the effect of treating dogs with OA with stem cells (SVF, stromal vascular fraction) and blood plasma rich in platelets (PRP) derived from the dog's own fat and blood, respectively. The mixture was administered as a single injection into affected elbows. Nineteen dogs with elbow OA were treated with SVF and PRP. Subjective and objective evaluations were performed before treatment, after six months, and after a minimum of one year. A "Symmetry Squares" graphic presentation of objective gait forces (peak force and impulse) was also used to compare changes in gait over time. The results showed that subjective evaluation of clinical lameness was improved at the six-month follow up evaluation and that the peak force was transferred from the hind limbs to the front limbs in the treated dogs after 12 months. However, the treatment failed to show a general evident effect. Further research should be conducted to evaluate whether SVF and PRP treatment should be recommended for dogs with elbow OA. (1) Background: The aim of the current pilot study was to describe the long-term effects of a single intra-articular injection of autologous stromal vascular fraction (SVF) with platelet-rich plasma (PRP) in dogs with confirmed elbow OA, using orthopedic lameness scoring and kinetic and kinematic gait analysis. For comparison of normal long-term variation of gait over time, a group of healthy control dogs (CDs) was also evaluated. (2) Methods: A prospective longitudinal clinical pilot study investigating 19 client-owned dogs with elbow OA (OADs) treated with SVF and PRP and eight CDs not receiving treatment. The OAD and CD groups were evaluated before and after 6 and at least 12 months following treatment with SVF and PRP (OAD group) and twice with a six-month interval (CD group), respectively, through orthopedic examinations, goniometry, and kinetic and kinematic analyses (seven variables). (3) Results: The OAD had an increase in fore-hind peak force symmetry >= 12 months after treatment (p < 0.05), but no other objective variables changed over time. Orthopedic consensus scores had improved at >= six months follow-up evaluation (p < 0.05). None of the investigated gait variables had changed at >= six months follow-up evaluation in the CD group. (4) Conclusions: The current study could not confirm a significant benefit from SVF and PRP treatment in OADs, but future studies should be conducted in order to fully evaluate the potential of the treatment. The improvement seen in fore-hindlimb symmetry may represent an improvement in gait or an incidental finding.
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| 4. |
- Braam, Åsa, et al.
(författare)
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Genetic variation in durability of Swedish Warmblood horses using competition results
- 2011
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 142, s. 181-187
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to investigate the possibilities of using number of years in competition as a measure of durability in the genetic evaluation of Swedish Warmblood horses. Competition results recorded between 1971 and 2008 in the disciplines dressage, show jumping and eventing were used to estimate genetic parameters for number of years in competition. Only male horses not used in breeding born between 1967 and 1991 were included in the study (17,962 horses). The study showed that horses with placings in more than one discipline at an early age had the longest competition career. This result suggests that these horses are talented for sports and possibly also that there is a positive effect of all-round training of young horses on their durability. For estimation of genetic parameters for number of years in competition different linear mixed animal models were compared. Depending on the model and transformation the heritability for total number of years in competition varied between 0.07 and 0.17. The lower values were obtained when adjustments in the model were made for age at first placing in competition. Higher heritabilities were obtained for competition years in show jumping and lower for eventing. Performance traits scored at young horse tests and as points in competition (lifetime and for young horses) showed positive genetic correlations with total number of years in competition. These results indicate that years in competition represent both the durability of the horses and their talents for performance. It is suggested that number of years in competition may be used for genetic evaluation of durability.
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| 5. |
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| 6. |
- Byström, Anna, et al.
(författare)
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Asymmetries of horses walking and trotting on treadmill with and without rider
- 2020
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Ingår i: Equine Veterinary Journal. - : Wiley. - 0425-1644 .- 2042-3306. ; 53, s. 157-166
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Tidskriftsartikel (refereegranskat)abstract
- Background Left-right movement symmetry is a highly desirable characteristic in sport horses.Objectives This study compared movement symmetry in well-trained dressage horses in unridden and unrestrained position and ridden in a dressage frame, and investigated possible associations between gaits.Study design Experimental study.Methods Seven sound, high-level dressage horses were measured at walk and sitting trot on a treadmill at several speeds under two conditions: with and without rider. Left-right differences in stance duration, stance protraction and retraction based on longitudinal hoof positions, ipsilateral limb tracking, minimum and maximum vertical positions of the dorsal spinous processes of the sixth thoracic (T6), third sacral vertebrae (S3) and wing of atlas, and vertical ground reaction forces were calculated and analysed in mixed models.Results At walk, five body variables indicated increased asymmetry in the ridden condition compared with unridden condition: forelimb stance duration (unridden/ridden left-right differences 9 vs 13 ms; P = .008), forelimb stance protraction (P = .004), stance retraction (P = .001) and first force peak (P = .003), and hindlimb stance retraction (P = .01). At trot, six body variables were more asymmetrical in the ridden condition: forelimb stance duration (2.5 vs 3.8 ms, P = .004); hindlimb stance protraction (P < .0001) and retraction (P = .01), T6 minimum (4 vs 6 mm, P = .001), T6 maximum (9 vs 11 mm, P = .01) and S3 maximum (6 vs 12 mm, P < .001). Five variables had significant associations between asymmetries at walk and trot, but only three demonstrated a positive slope.Main limitations A limited number of horses and riders were studied. Measurements were performed on a treadmill.Conclusions High-level horses moved slightly more asymmetrically when ridden in a dressage frame than in the unridden condition.
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| 7. |
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| 8. |
- Byström, Anna, et al.
(författare)
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Biomechanical findings in horses showing asymmetrical vertical excursions of the withers at walk
- 2018
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- The walk and trot are inherently symmetrical gaits, making them potentially suitable for the detection of left-right asymmetries. The aims of this study were to describe asymmetrical vertical excursions of the withers at walk in non-lame high-level dressage horses and to seek associations between these asymmetric movements and other kinematic variables and vertical ground reaction forces (vGRFs). Seven dressage horses, judged clinically as being sound, walked unridden and unrestrained on a treadmill with an integrated force measuring system (480 Hz), from which spatiotemporal and vGRF variables were extracted. Markers were tracked by 12 infrared cameras (240 Hz). The vertical position of the sixth thoracic vertebra (T6), limb protraction and retraction distances throughout stance, and global limb lengths were determined. Contralateral trial-mean differences were calculated, including difference in T6 minimum vertical position between contralateral steps (T6minDiff). Mixed models were used to study associations between symmetry parameters. Trial-mean T6minDiff ranged between 0.3-23 mm. Of the seven horses, five consistently dropped the withers more in early left forelimb stance, one was fairly symmetrical, and one dropped the withers more in early right forelimb stance. Comparisons between contralateral limbs showed the following associations. The forelimb that was retracted when T6min was lowest showed greater retraction at toe-off (1 mm increase predicted 0.17 mm T6minDiff increase) and shorter stance duration (1 ms decrease predicted 0.3 mm T6minDiff increase). The hind limb that was in midstance when T6min was lowest showed a greater range of motion during the stance phase (1 mm increase in protraction or retraction predicted 0.2 mm T6minDiff increase). The haunches were displaced away from the side of the forelimb that was protracted when T6min was lowest (1 mm lateral shift predicted 0.07 mm T6minDiff increase). Forelimb and hind limb vGRF parameters were non-significant. Asymmetry of vertical withers movement in horses assessed as being sound at trot was related to a complex pattern of asymmetries in spatiotemporal variables throughout the stride cycle rather than to vertical load redistribution between the forelimbs. This suggests that the asymmetry may be due to inherent laterality rather than weight-bearing lameness.
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| 9. |
- Byström, Anna, et al.
(författare)
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Differences in equine spinal kinematics between straight line and circle in trot
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Work on curved tracks, e.g. on circles, is commonplace within all forms of horse training. Horse movements in circles are naturally asymmetric, including the load distribution between inner and outer limbs. Within equestrian dressage the horse is expected to bend the back laterally to follow the circle, but this has never been studied scientifically. In the current study 12 horses were measured (optical motion capture, 100 Hz) trotting on left and right circles and on the straight without rider (soft surface). Data from markers placed along the spine indicated increased lateral bending to the inside (e.g. left bending on the left circle) of the thoracolumbar back (difference left circle vs. straight - 3.75 degrees; right circle+3.61 degrees) and the neck (left - 5.23 degrees; right+4.80 degrees vs. straight). Lateral bending ROM increased on the circle (+0.87 degrees and+0.62 degrees). Individual variation in straight-circle differences was evident, but each horse was generally consistent over multiple trials. Differences in back movements between circle and straight were generally small and may or may not be visible, but accompanying changes in muscle activity and limb movements may add to the visual impression.
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| 10. |
- Byström, Anna, et al.
(författare)
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Differences in rider movement pattern between different degrees of collection at the trot in high-level dressage horses ridden on a treadmill
- 2015
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Ingår i: Human Movement Science. - : Elsevier BV. - 0167-9457 .- 1872-7646. ; 41, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Collection is a central term in equine dressage, defined as a shortening of the horse's stride length with retained energy and hind limb activity. How collection is induced by the rider has yet not been investigated objectively. The aim of this study was therefore to compare the movement pattern of high-level dressage riders between free trot (loose reins), passage and a range of three speeds in collected trot.Both at higher speed in collected trot and in passage, the rider's pelvis became more caudally rotated and the rider's lumbar back became more flexed. However, in passage there was also a decrease in phase-shift between horse and rider movements, suggesting that the rider used the seat more actively. In free trot, the rider's pelvis was more cranially rotated, the lumbar back was more extended, the rider's body inclined more forwards, and the phase-shift between horse and rider was increased, compared to collected trot. The observed changes were partly explainable from changes in the horse's movement pattern. However, most differences in rider body position seemed unrelated to the horse's movements, but were in accordance with instructions in equestrian texts, suggesting that those changes were voluntarily adopted by the riders. (C) 2015 Elsevier B.V. All rights reserved.
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