Association of force plate and body-mounted inertial sensor measures for determination of hind limb lameness in horses

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] The purpose of this study was to investigate the association between inertial sensor and stationary force plate measures of hind limb lameness. 21 adult horses that were either sound or had mild hind limb lameness were utilized. Horses were instrumented with inertial sensors and evaluated for lameness with a stationary force plate while trotting straight. Inertial sensor-derived measurements for maximum (Pmax) and minimum (Pmin) pelvic height differences between right and left halves of the stride were compared to vertical (VGRF) and horizontal (HGRF) ground reaction forces. Stepwise linear regression was performed to investigate strength of association between inertial sensor measures of hind limb lameness and amplitude, impulse, and time indexes of important events in VGRF and HGRF. Pmin was moderately associated with peak VGRF (Vmax; R2a = 0.60) but had little association with HGRF. Pmax was strongly associated with a combined decrease in VGRF impulse (Vauc2) and an increase in HGRF impulse (Hauc+) in the second half of stance (R2a = 0.77) but was not associated with Vmax. The inertial sensor-derived measure of asymmetric pelvic fall (Pmin) estimates decreases in Vmax and total VGRF impulse, but the inertial sensor-derived measure of asymmetric pelvis rise (Pmax) estimates a transfer of Vauc2 to Hauc+. Evaluation of both pelvic rise and fall are important when assessing hind limb lameness.