Understanding hind limb lameness signs in horses using simple rigid body mechanics

Alterations in body lean angle in lame horses before and after diagnostic analgesia in straight lines in hand and on the lunge

“…The pelvis, lumbar and caudal thoracic region can be described as a rigid body with regard to axial rotation in non-lame horses (Faber et al, 2001). Although it is possible that some horses with lameness in straight lines exhibit a 'pelvic roll bias' that is different from the trunk, it was demonstrated that on average the pelvic asymmetry patterns observed in horses with varying degrees of lameness can be explained by a simple rigid body model, without the need to alter pelvic roll bias (Starke et al, 2015).…”

Quantification of the effect of instrumentation error in objective gait assessment in the horse on hindlimb symmetry parameters

“…As shown by our results, this could be due to changes in the pelvis rotation pattern. Nevertheless, the effect of lameness in pelvis rotation is known to be small . To study this, a kind of dose‐effect study would have to be conducted in a larger population of horses.…”

“…In the present study, we used a small but diverse population of horses to avoid bias by any specific breed‐related morphological characteristics. It is unknown if different degrees of lameness that ultimately may alter the motion pattern of the pelvis could affect the model estimates we describe, but, as previously described, the horses included in this study were mildly asymmetrical (Table ) and one of the horses even had a consistent pelvis movement asymmetry (PDmin = 13.3(±6.0) mm and Hip‐Hike Diff = 21.4(±8) mm). Further studies are needed to better understand the effect of marker misplacement on our investigated symmetry parameters in lame horses.…”

“…We did observe a difference in amplitude of the signals and a difference in maximum and minimum vertical position when compared to the reference marker (Fig ). This can be explained by the fact that the pelvis behaves like a rigid body ; therefore, when using markers attached to the same rigid structure, vertical displacement events happen synchronously through the whole structure. For the calculated symmetry parameters of the sacrum, left/right misplacement had a considerably greater effect when compared to cranial/caudal misplacement.…”

Range of motion and between-measurement variation of spinal kinematics in sound horses at trot on the straight line and on the lunge

“…The ICCs are highest in pelvic motion (Table 3). This can be explained by the pelvis behaving as a rigid body(33), whereas the back segments regard anatomical locations containing various joints. Furthermore, marker configuration may play a role here; both tuber coxae and tuber sacrale markers form one single unit and are hence less prone to effects of marker (mis)placement (32).…”