Effects of draw reins on limb kinematics.
BACKGROUND
No data exist on the GRF-kinematics relation due to changes caused by equestrian interventions.


OBJECTIVE
Through the judicious use of draw reins the rider can influence the kinematics of the horse to meet stated goals of dressage training. Relating the results to previously published kinetic data of the same experiment implies a possible relationship between kinetics and kinematics.


METHODS
The kinematics of 8 sound Swedish Warmblood horses were measured whilst the horses were being ridden with and without draw reins. Three conditions were evaluated: 1) draw reins only (DR), 2) combination of draw reins and normal reins (NR+DR) and 3) normal reins only (NR).


RESULTS
Head and neck angles were significantly decreased by the draw rein but 4-5 times more so for DR when with NR+DR. The forelimb position at hoof lift-off was significantly more caudal with DR. In the hind limb the hip joint extended more quickly and the hock joint flexed more with NR+DR than with NR. Compared to DR the hip joint angular pattern was not significantly different, but the pelvis was more horizontal.


CONCLUSIONS
Riding with a draw rein can have significant influence on the kinematics of the horse. Some of the observed changes can be coupled to changes in kinetics. The hock joint angle seems to be a fairly reliable indicator of load on the hind limb and the angle of femur appears important for hind limb propulsion, when considered in conjunction with the orientation of the pelvis.


CONCLUSIONS
These findings are important for riders and trainers, as kinematic changes are what trainers observe. It is thereby important to ascertain which kinematic changes are consistently coupled to changes in kinetics in order for trainers to be able to judge correctly the success of intended goals. Further studies are warranted to validate and confirm suggested relationships between kinetics and kinematics.
Byström
A
A
Department of Equine Studies, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden.
Roepstorff
L
L
Johnston
C
C
D000818:Animals; D001696:Biomechanical Phenomena; D005080:Exercise Test; D005552:Forelimb / Q000502:physiology; D006257:Head / Q000502:physiology; D006614:Hindlimb / Q000502:physiology; D006736:Horses / Q000502:physiology*; D006801:Humans; D009068:Movement / Q000502:physiology; D009333:Neck / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000379:methods* / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology