The effect of ground and raised trot poles on hind limb joint range of motion in the ridden horse.

Introduction: Musculoskeletal conditions that affect the joints and muscles of equine athletes have been seen to be prominent in shortening successful competitive careers. In the unridden horse, ground and raised trot poles have been observed to improve balance and muscular control, and strengthen flexor and core stabilising musculature, as well as increasing limb joint ranges of motion (Brown et al., 2015). Addition of a rider increases ground reaction forces on the horse’s limbs and has an overall extending effect on the back and dorsal muscle chain (De Cocq et al., 2009). Therefore, the aim of this study was to evaluate the kinematics of the femorotibial, tarsus and metatarsophalangeal joints of ridden horses trotting over no poles, ground poles and raised poles.
Material and Methods: 9 horse (mean ± standard deviation; age 9 ± 2 years; height 166cm ± 10cm) and rider partnerships were recruited from the student livery population at Hartpury University. All horses were confirmed sound to be ridden over poles by a veterinarian and ridden by their usual rider. Skin fixed markers were placed on relevant anatomical sites to mark out the femorotibial joint, tarsal joint and metatarsophalangeal joint. Horses were required to trot over no poles (NP), ground poles (GP) and raised poles (RP; 20cm to bottom of pole) in a randomly assigned order to collect 3 clean repetitions. Before starting data collection, horses were warmed up for 10 minutes in walk, trot and canter following their normal routine. Poles were placed at 1.20m ± 0.10m apart in an indoor arena within a marked lane, 25 metres in length and 2 metres wide. Optimum distances between poles were individualised for each participant and confirmed in a practice trial. Two cameras were set up perpendicular and 7.5m from the centre to the lanes to capture strides at 120Hz. A related-samples Friedman’s two-way analysis of variance by ranks test was used to identify significant differences, pairwise Wilcoxon comparisons were also used to explore and locate any significant differences between the range of motion (ROM) of each joint throughout the 3 exercise conditions.
Results: All joints produced a range of motion which significantly increased over GP and RP compared to NP. There was overall a significant (p<0.05) but asymmetrical response to the exercise conditions in the ROM of the left and right femorotibial joints based on post hoc testing; see Figure 1. The metatarsophalangeal and tarsal joints similarly show significant stepwise increases in ROM between the three conditions across both limbs (p= <0.001; p= <0.001).