A relaxed and co-operative horse is expected to perform better in dressage. This study tested the effect of ProKalm (Science Supplements™, U.K.) or a placebo on gait and dressage score. Horses and ponies (n=25) were recruited from British Dressage Northern region and ridden by their usual riders. All horses were currently competing at Novice to Advanced level. Each horse on each of the three occasions performed, in order, a medium walk, free walk, working, collected, medium and extended trot and a working canter on both reins. Each movement was recorded three times in each direction, giving a minimum of fifteen strides. Subjects were assessed on three occasions each, once without any treatment, once with a placebo and once with the calmer in a Latin-Square design. Horses received 64g of ProKalm per day split between 2 feeds or a placebo for 3 days and were then tested on the 4th day after receiving half of the daily dose.
Each movement was filmed in three dimensions at high-speed (300Hz) for marker-free biomechanical kinematic analysis and simultaneously in two dimensions at 25Hz to allow 3 dressage judges unaware of the study or its purpose to subsequently score the movements blinded to treatment. The biomechanical variables and score were analysed using a multivariate repeated measures analysis (MANOVA), which considered each gait separately.
The placebo had a strong, positive effect on the horse and rider’s performance and this was used to give a baseline for inter-trial variability. ProKalm did not have a significant effect on the biomechanics of either of the walks tested (P>0.05). ProKalm did have significant positive effects on the stride length, metacarpo-phalangeal angles, tibio-tarsal angles and moments, and centre of gravity displacements (P<0.05) at trot and canter. Peak tibio-tarsal angle, as an index of hind-limb engagement, was found to significantly increase in the case of ProKalm treatment in all trots (8±3%, P=0.03). Metacarpo-phalangeal joint peak angle significantly increased during stance in the case of the ProKalm in collected (2±2%, P=0.05) and working trots (3±1%, P=0.03). Tibio-tarsal joint moments showed that a significantly higher joint moment was generated at collected (10±3%, P=0.03) and working trots (9±3%, P=0.02) and at the canter (6±3%, P<0.05) with ProKalm. The horses’ centre of gravity displacement (vertical motion) also significantly increased with ProKalm compared with the placebo (P<0.05). Stride length increases significantly with ProKalm in working (7±2%, P<0.05) and extended trots (9±4%, P<0.05) and in canter (7±4%, P<0.05), but not in collected trot (P>0.05). There was a significant increase in the judge’s scores (P<0.05) above the inter-trial variability with the placebo.
In conclusion, in a placebo-controlled study in which riders and judges were blinded as to treatment, ProKalm fed at 64g/day for 3 days prior to a standardised test produced significant positive changes in stride length, metacarpo-phalangeal angles, tibio-tarsal angles and moments and centre of gravity displacements in trot and canter and a significant increase in judges scores compared with a placebo.
“The significant results of this study demonstrate the positive benefits of a more relaxed and co-operative horse and we are investing more research into this field with the aim of publishing a full study,” said Vicky Mitson.