Accuracy and precision of hind limb foot contact timings of horses determined using a pelvis-mounted inertial measurement unit

A preliminary investigation of the use of inertial sensing technology for the measurement of hip rotation asymmetry in horse riders

“…IMUs have been used successfully in equine gait analysis (Pfau, Witte & Wilson 2005;Thomsen, Jensen, Sørenson, Lindegaard & Andersen 2010;Starke, Witte, Maya & Pfau 2012). These have shown the presence of asymmetry in the horse, so it is necessary to consider whether the asymmetry shown in the rider is related to, and consistent with, asymmetry of the horse, or if they are independent.…”

Measurement of horses gaits using geo-sensors

“…In Bartlett's Method, the data set is divided equally without overlaps, while in Welch's method, two modifications are made, the first is to allow overlaps between each section of data, and the amount of overlap is either 50% or 75%, the second is to allow a data window to be applied to each section, thus result in modified periodograms. Assuming x[n] is divided into K sections and each section has a length of L, and has 50% overlap, then the following relationship can be derived [11] 1 2   L K ( 17 ) and the Variab N ility, which is the normalized variance, and resolution of the periodograms are given by [11] …”

“…For example, accelerometers were placed on all four hoofs of horses to study the hoof impact of different stride types and functional limb types by E. Hernlund et al [16]. S. D. Starke et al [17] used a combination of devices to evaluate the accuracy and precision of foot contact timings of horses, including a hoof-mounted accelerometer. L. H. Douilly et al [18] studied the hoof slip distance by placing piezoelectric accelerometer at the right front hoof of the horse.…”

Is a standalone inertial measurement unit accurate and precise enough for quantification of movement symmetry in the horse?

“…A head mounted sensor seems more obvious to quantify front limb lameness. In order to distinguish between left and right sided lameness with a single sensor (Starke et al, 2012b), additional parameters need evaluating together with vertical movement. Head roll appears to be an unreliable indicator of the side of asymmetry since horses limit out of plane movements of the head (Dunbar et al, 2008).…”

“…The sternum has been used previously (Barrey et al, 1994) and body orientation seems better suited than head orientation. In multi-sensor systems with synchronized sensors (Warner et al, 2010, Starke et al, 2012a,c, Pfau et al, 2012, the sacral sensor can be used to segment all sensor data (Starke et al, 2012b). If thoracic limb hoof contact is required, IMUs located on the distal limb (Olsen et al, 2012) or hoof mounted accelerometers or gyroscopes (Witte et al, 2004, Keegan et al 2005 provide precise results.…”