Performance-related data capture based on inertial sensors for movement monitoring in equestrian show jumping

Abstract

A cross-sectional study with five different experienced show jumping and eventing horses was undertaken to prepare a simple and versatile possibility to objectify jumping movement in training and competition in order to optimize training and health maintenance. From the state of scientific research, continuing theoretical considerations and previously performed measurements with the selected inertial sensors, a large pool of possible performance-relevant parameters is selected. Its presentability should be proofed in the next step in field trials by an inertial measurement unit embedded in a saddle belt. The horses were ridden over a single vertical fence with a height of 1.30m. For the purpose of a standardized jumping movement, a gymnastic series is prefixed in half of the trials (n=30). The other half is approached in normal canter. A three dimensional accelerometer and a gyroscope, embedded in the saddle belt, illustrate the kinematics of the horses trunk. In three body planes, the translational and rotational movement of the horses trunk results in a consistent pattern of movement with striking points while jumping. In translation, there is a maximum dorsal acceleration of the fore limbs and of the hind limbs in take-off as well as of the fore limbs in landing in sagittal direction. In longitudinal direction, caudal and cranial maximum values of the fore limbs and the hind limbs in take-off are visible. Additionally, with the rotation, velocity around the body width axis at takeoff (dorsal), in suspension (ventral) and after landing (dorsal) are clearly detectable. The translation in the transverse direction as well as the rotation around the body length and body depth axis do not result in evaluable movement patterns. Other important parameters like the velocity of approach, takeoff and landing as well as the take-off and landing distance and angle cannot be obtained from the inertial data. Comparing the results of the different horses, a main effect due to the individuality of each parameter (p<0.01) can be shown. In comparison to the approach in canter, approaching out of a gymnastic series of obstacles leads to a significantly higher velocity of approach (p < 0.05), to a significantly smaller take off distance between the second hind limb and the baseline of the obstacle (p < 0.05) and to a significantly higher minimum of angular velocity in suspension (p < 0.05). By MANOVA, no interaction effects between the two factors "Horse" (p > 0.05) and "Approach" (p > 0.05) can be shown. The illustration of take-off and landing velocity, distance and angle of the horses trunks in take-off and landing as well as the approaching speed by integration of the inertial data is not possible yet. The drift of the sensors is too high. In conclusion the inertial measurement system appears to be suitable to present jumping kinematics in the field. The conducted investigation implies the possibility to compare the intra-individual kinematics of horses trunks in show jumping. Because the measurement error accumulated rapidly over measurement duration, the gyroscope data cannot be used to determine the sensor s orientation. To shorten the measurement duration, a known integration constant close to the take-off position is necessary. Further examination with a larger number of horses is necessary to evaluate and interpret the inertial parameters in relation to individual performance. Additionally, physical properties of each sensor, possibilities to determine IMUs orientation as well as the accuracy of the whole measurement unit have to be proofed in order to create a fitting filter system for an autonomous self-tracking system. Therewith, the usage of the IMU saddle belt without an external source as well as the illustration of the kinematics in relation to the world-coordinate-system become possible. Otherwise, kinematic data in relation to the sensor-coordinate-system has to be evaluated in a further investigation with a larger number of horses in order to explain the coherence to performance and success.