Withers vertical movement symmetry is useful for locating the primary lame limb in naturally occurring lameness

Abstract

BackgroundDuring orthopaedic assessment of lame horses, a head nod is commonly present in both primary forelimb and hindlimb lame horses. Additional motion metrics that could assist clinicians in correctly differentiating between these two scenarios would be of great clinical value.ObjectivesThe primary objective of this study was to examine whether withers movement asymmetry can be used in a clinical setting to distinguish primary forelimb lameness from compensatory head movement asymmetry due to primary hindlimb lameness.Study designRetrospective, multicentre study.MethodsMovement asymmetry of head, withers and pelvis was measured using multi‐camera optical motion capture, as part of routine lameness investigations at four European equine hospitals. Vertical movement asymmetry parameters from 317 horses trotting in a straight line were compared before and after successful diagnostic analgesia of a single limb. Descriptive statistics, t‐tests and linear models were used to analyse the data.ResultsIn forelimb lame horses, 80%–81% showed head and withers asymmetry both indicating lameness in the same forelimb. In hindlimb lame horses, 69%–72% showed head asymmetry ipsilateral to the lame hindlimb and withers asymmetry diagonal to the lame hindlimb, thus, head and withers asymmetry indicated lameness in different forelimbs. A large (>15 mm) compensatory head nod was seen in 28%–31% of the hindlimb lame horses. In 89%–92% of these, head and withers asymmetry indicated lameness in different forelimbs. Withers asymmetry decreased linearly with reduced head or pelvic asymmetry for both forelimb and hindlimb lame horses.Main limitationsCompensatory strategies were evaluated on group level to identify common patterns, potentially ignoring uncommon individual strategies.ConclusionsWithers vertical movement asymmetry metrics can be useful in helping to locate the primary lame limb during quantitative lameness assessment. Head and withers movement asymmetry parameters generally indicate the same forelimb in forelimb lame horses, but different forelimbs in hindlimb lame horses.

Prevalence of movement asymmetries in high-performing riding horses perceived as free from lameness and riders’ perception of horse sidedness

“…Even for the horses in this study population exhibiting movement asymmetries just above the thresholds, the magnitude of these asymmetries falls within the range reported for clinically lame horses with a positive response to diagnostic analgesia [ 17 , 18 , 33 ]. Consequently, 69% of the horses in this high-performing population displayed movement asymmetries that could potentially indicate a painful condition.…”

Adaptation strategies of the Icelandic horse with induced forelimb lameness at walk, trot and tölt

“…The first limitation is that we used an acute but reversible sole‐pressure lameness induction model, which differs from many pathologies in lame horses. However, when the same lameness induction method on warmbloods was used, 22 lameness patterns were similar to those seen later in clinical cases with different kinds of pathologies 35 . Second, only one surface type was investigated, which is known to affect kinematics and stride temporal parameters 36 .…”

“…However, when the same lameness induction method on warmbloods was used, 22 lameness patterns were similar to those seen later in clinical cases with different kinds of pathologies. 35 Second, only one surface type was investigated, which is known to affect kinematics and stride temporal parameters. 36 Finally, only subtle/mild lameness was…”

Pilot study of locomotor asymmetry in horses walking in circles with and without a rider

“…If the relation between head movement and limb loading is similar for lameness and for normal walk on a circle, this would suggest that right-hollow horses had decreased weight-bearing on the left (outside) forelimb in right direction. In trot, offloading of a forelimb will result in both head and withers vertical motion asymmetry ( Persson-Sjödin et al, 2023 ). However, neither WMinDiff nor WMaxDiff have been found to be associated with lameness in walk, at least not on a straight line ( Buchner et al, 1996 ; Serra Bragança et al, 2021 ).…”