Sensor based training registration in riding horses : possible association between training regimen and locomotion asymmetry

Sammanfattning: Lameness remains a significant welfare concern in riding horses, with over 50% of documented equine injuries attributed to this condition. The precise quantification of training activities and the objective assessment of asymmetry can contribute substantially to our comprehension of the impact of training on injury occurrence and overall performance in riding horses. This pilot study aimed to document the training routines of 24 riders with 29 horses over an 8-week period. The horses used in the study were used for either dressage (n=15), show jumping (n=5), or all-round riding (n=9). They underwent weekly assessments of locomotion asymmetry on both hard and soft footing using the Lameness Locator sensor-based system. As a measure of total asymmetry, vector sums (VS) where calculated for both front and hind limbs, respectively. Activities during training sessions were registered using an inertial measurement unit (Equisense), attached to the saddle girth and connected to a smartphone application, which detected gaits and quantified time spent in each gait. In the overall horse population, a normal training week (n=139 weeks) consisted of an average (±std) of 5.0±1.4 sessions, with 4.0±1.4 days in the arena and 1.0±1.0 days spent hacking. No significant differences were observed between disciplines in terms of the number of training sessions or sessions performed on an arena. An average training session (n=663) lasted 42±9 minutes, comprising 25±8 minutes of walk (58% of the duration), 11±4 minutes of trot (26%), and 7±3 minutes of canter (16%). The distribution of gaits within training sessions varied according to discipline. Dressage horses trotted more (12±1 minutes) than allround horses (9±1 minutes, P<0.01), cantered less (5±1 minutes) compared to both show jumping horses (8±1 minutes, P<0.05) and allround horses (8±1 minutes, P<0.01). Dressage horses also exhibited greater locomotion asymmetry in their front limbs (VS: 10.45±0.68) than all-round horses (VS: 8.34±0.78, P<0.05). A weak positive correlation (r=0.165, P<0.01) emerged between increased trotting during training sessions and heightened asymmetry, suggesting that horses subjected to more trotting displayed greater asymmetry. Locomotion asymmetry fluctuated between weeks, with elevated VS for front limbs during weeks 5, 6, and 7, and elevated VS for hind limbs during weeks 3, 5, and 7 compared to other weeks (P<0.05). The diverse training regimens observed across horse groups participating in different disciplines indicate that a considerably more extensive study could yield insights into the correlation between training session composition and asymmetry development. However, accurate registrations necessitate a reliable, user-friendly device, and rider compliance is essential. The intriguing variation in locomotion asymmetry warrants further investigation to delineate the normal range of variation in different disciplines and elucidate how training practices contribute to locomotion asymmetry.