The effect of trotting speed on the evaluation of subtle lameness in horses.

1. Vet J. 2013 Apr 20. pii: S1090-0233(13)00108-1. doi: 10.1016/j.tvjl.2013.03.006. 
[Epub ahead of print]

The effect of trotting speed on the evaluation of subtle lameness in horses.

Starke SD, Raistrick KJ, May SA, Pfau T.

Department of Veterinary Clinical Sciences, The Royal Veterinary College, North
Mymms, Hatfield AL9 7TA, UK; Structure and Motion Laboratory, The Royal
Veterinary College, North Mymms, Hatfield AL9 7TA, UK. Electronic address:
sstarke@rvc.ac.uk.

Equine lameness is a significant and challenging part of a veterinarian's
workload, with subtle lameness inherently difficult to assess. This study
investigated the influence of trotting speed on perceived and measured changes in
movement asymmetry. Ten sound to mildly lame horses were trotted at a 'slow',
'preferred' and 'fast' speed on a hard surface, both on a straight line and in a 
circle on left and right reins. Video recordings of the horses were visually
assessed by six experienced equine clinicians. Vertical movement of head, withers
and pelvis was derived from inertial sensor data and several features calculated.
On the straight line, more horses were subjectively declared sound at higher
speeds, whilst different objective asymmetry measures showed only slight and
inconsistent changes. On the circle, speed had no significant effect on the
subjective assessment, with an increase in objectively measured asymmetry at
higher speeds possibly balanced by a decrease in sensitivity of the observers for
this asymmetry. Horses visually examined for subtle lameness on the straight
should therefore be evaluated at a slow speed. Trotting speed should be
consistent on repeated occasions, especially during objective gait analysis on
the circle, to avoid the interaction of treatment effects and speed effects.

Copyright © 2013 Elsevier Ltd. All rights reserved.

PMID: 23611486  [PubMed - as supplied by publisher]