Gait analysis in the horse: The use of distal limb mounted Interial Measurement Unit sensors for the detection of induced ataxia in horses.

Abstract

Reasons for performing study: Inertial Measurement Unit (IMU) sensor based techniques are becoming more popular for use in horses as a tool for objective locomotor assessment. Using currently proposed algorithmic methods only limited information about stride variables can be obtained for incoordination.

Objective: To compare several limb kinematic parameters in neurologically sound horses before and after induction of ataxia by intravenous alpha-2 agonist administration.

Study design: Prospective validation study comparing IMU sensors and motion capture with force plate data as the gold standard.

Materials & Methods: This was a pilot study. Kinematic stride parameters were obtained with IMU sensors from 2 horses at walk and at trot. The horses were measured with and without sedation with detomidine. Horses were instrumented with 8 IMU sensors, 4 placed on the limbs; one on each limb, and 4 placed on the upper body; head, withers, sternum and tuber sacrale.

Results: Comparing the stance duration (StD, P = 0.012), swing duration (SwD, P = 0.017) and stride duration (StrD, P = 0.012) at walk of neurological sound horses with, and without sedation, the results were significantly different. At trot the results were significantly different; StD (P = 0.018), SwD (P = 0.019) and StrD (P =0.011). Comparing the coefficient of variation (CV)of the StD, SwD and StrD of neurological sound horses, the StD (P = 0.017) and StrD (P = 0.012) were significantly different, conforming a higher inter stride variation. The SwD (P = 0.263) was not significantly different. At trot, the CV of StD (P = 0.123), SwD (P = 0.400) and StrD (P = 0.208) were not significantly different.

Conclusion: The kinematic stride parameters of sedated horses is best observed and diagnosed at walk. Apparently, the pendulum at trot makes coordination for sedated horses more easy.