Summary 25Gait analysis is gaining in popularity for quantification of lameness and two commonly used inertial 26 sensor systems assess trunk movement symmetry: can these be used interchangeably in multi 27 centre studies? 28We compared head and pelvic movement symmetry between two inertial sensor gait analysis 29 systems in 13 horses equipped simultaneously with the two systems. The first system quantified 30 dorso-ventral movement in the local reference frame (System A), the other system global vertical 31 movement (System B). Widths of limits of agreement were calculated employing a well-established 32 regression method dealing with systematically changing differences over the range of measured 33 values. 34Widths of limits of agreement between system A and system B were narrower for pelvic movement 35 than for head movement. For head movement, they ranged from 6.4 to 6.9mm for in-hand trot and 36 from 7.3 to 9.7mm in the lunge and for pelvic movement from 2.5 to 4.4mm in-hand and from 3.6 37 to 5.3mm on the lunge. 38

Summary Reasons for performing study Lungeing is often part of the clinical lameness examination. The difference in movement symmetry, which is a commonly employed lameness measure, has not been quantified between surfaces. Objectives To compare head and pelvic movement symmetry between surfaces and reins during lungeing. Study design Quantitative gait analysis in 23 horses considered sound by their owners. Methods Twenty‐three horses were assessed in‐hand and on the lunge on both reins on hard and soft surfaces with inertial sensors. Seven movement symmetry parameters were quantified and used to establish 2 groups, namely symmetrical (n = 9) and forelimb‐lame horses (n = 14), based on values from straight‐line assessment. Movement symmetry values for left rein measurements were side corrected to allow comparison of the amount of movement symmetry between reins. A mixed model (P<0.05) was used to study effects on movement symmetry of surface (hard/soft) and rein (inside/outside with respect to movement symmetry on the straight). Results In forelimb‐lame horses, surface and rein were identified as significantly affecting all head movement symmetry measures (rein, all P<0.0001; surface, all P<0.042). In the symmetrical group, no significant influence of surface or rein was identified for head movement symmetry (rein, all P>0.245; surface, all P>0.073). No significant influence of surface or rein was identified for any of the pelvic movement symmetry measures in either group. Conclusions While more symmetrical horses showed a consistent amount of movement symmetry across surfaces/reins, horses objectively quantified as lame on the straight showed decreased movement symmetry during lungeing, in particular with the lame limb on the inside of a hard circle. The variation within group questions straight‐line movement symmetry as a sole measure of lameness without quantification of movement symmetry on the lunge, ideally on hard and soft surfaces to evaluate differences between reins and surfaces. In future, thresholds for lungeing need to be determined using simultaneous visual and objective assessment.

The gait scoring system developed by Manson and Leaver was used by five experienced observers to assess the gait of 83 milking Holstein-Friesian cows in a live recording session, and video recordings were made. The agreement between the scores of the observers at the live session, and between each observer's scores at the live session and a video session, were compared at three levels of stringency. The scores of the observers were highly variable at all but the least stringent threshold - whether a cow had a score of less than 3 or 3 or more, that is, whether it was not lame or lame.

Increases in trotting velocity in Greyhounds do not alter the basic patterns of work and power for various joints of the hind limbs, but local burst amplitudes during the stance phase increase incrementally.