Page 183 - Adams and Stashak's Lameness in Horses, 7th Edition

Examination for Lameness 149

Quantification of Asymmetry Quantification of Asymmetry
Stride Rate: 1.9 Strides Assessed (fore/hind): 27/27 Stride Rate: 1.6 Strides Assessed (fore/hind): 29/29
Forelimb Strides
Forelimb Strides
Hindlimb Strides
Hindlimb Strides
VetBooks.ir 60 40 Right Fore Lameness –30 Left Hind Lameness Right Hind Lameness 30 60 40 Right Fore Lameness –30 Left Hind Lameness Right Hind Lameness 30
Pushoff
Pushoff
Pushoff
Pushoff
Midstance
Midstance
–20
20
–20
20
20 Pushoff Impact – Diff Max (mm) –10 10 + Diff Max (mm) 20 Pushoff Impact – Diff Max (mm) –10 10 + Diff Max (mm)
Diff Min (mm) 0 0 0 Diff Min (mm) 0 0 0
–20 –10 10 –20 –10 10
Pushoff Impact Pushoff
Impact
–40 Midstance – Diff Min (mm) –20 20 + Diff Min (mm) –40 Midstance – Diff Min (mm) –20 20 + Diff Min (mm)
Left Fore Lameness Left Fore Lameness
–60 –30 Impact Impact 30 –60 –30 Impact Impact 30
–60 –40 –20 0 20 40 60 0 10 20 0 10 20 –60 –40 –20 0 20 40 60 0 10 20 30 0 10 20 30
Diff Max (mm) Stride Stride Diff Max (mm) Stride Stride
Lameness Metrics Lameness Metrics
Thresholds for Max/Min Head: ±6 mm Thresholds for Max/Min Pelvis: ±3 mm Thresholds for Max/Min Head: ±6 mm Thresholds for Max/Min Pelvis: ±3 mm
Diff Max Head: Mean: 0.3 mm SD: 12.5 mm Diff Max Pelvis: Mean: –9.1 mm SD: 5.9 mm Diff Max Head: Mean: –22.0 mm SD: 10.4 mm Diff Max Pelvis: Mean: 6.0 mm SD: 4.4 mm
Diff Min Head: Mean: 20.3 mm SD: 12.7 mm Diff Min Pelvis: Mean: –0.6 mm SD: 6.2 mm Diff Min Head: Mean: –33.3 mm SD: 10.4 mm Diff Min Pelvis: Mean: 0.8 mm SD: 4.2 mm
Threshold for Total Diff Head: 8.5 mm Threshold for Total Diff Head: 8.5 mm
Total Diff Head (Vector Sum): 20.3 mm Total Diff Head (Vector Sum): 39.9 mm
Q Score (fore): R 20.3 Mid Q Score (hind): L 9.1 Push / L 0.6 Imp Q Score (fore): L 39.9 Imp Q Score (hind): R 6.0 Push / R 0.8 Imp
Figure 2.140. Lameness Locator® reports of multiple limb lameness. Best explanation is second part of the law of sides, or
lameness. Left report: Left hindlimb pushoff only, no impact lameness, primary forelimb lameness with compensatory contralateral hindlimb
and contralateral right forelimb lameness. Right report: Right hindlimb pushoff lameness.
pushoff only, no impact lameness, and contralateral left forelimb
Quantification of Asymmetry Quantification of Asymmetry
Stride Rate: 1.7 Strides Assessed (fore/hind): 23/26 Stride Rate: 1.5 Strides Assessed (fore/hind): 38/38
Forelimb Strides Hindlimb Strides Forelimb Strides Hindlimb Strides
60 –30 Left Hind Lameness Right Hind Lameness 30 60 –30 Left Hind Lameness Right Hind Lameness 30
Pushoff Pushoff Pushoff Pushoff
Right Fore Lameness Right Fore Lameness
40 Midstance –20 20 40 Midstance –20 20
Pushoff Impact – Diff Max (mm) + Diff Max (mm) Pushoff Impact – Diff Max (mm) + Diff Max (mm)
20 –10 10 20 –10 10
Diff Min (mm) 0 0 0 Diff Min (mm) 0 0 0
–20 –10 10 –20 –10 10
Pushoff Impact Pushoff
Impact
–40 – Diff Min (mm) 20 + Diff Min (mm) –40 – Diff Min (mm) + Diff Min (mm)
Midstance –20 Midstance –20 20
Left Fore Lameness Left Fore Lameness
Impact Impact Impact Impact
–60 –30 30 –60 –30 30
–60 –40 –20 0 20 40 60 0 10 20 0 10 20 –60 –40 –20 0 20 40 60 0 10 20 30 0 10 20 30
Diff Max (mm) Stride Stride Diff Max (mm) Stride Stride
Lameness Metrics Lameness Metrics
Thresholds for Max/Min Head: ±6 mm Thresholds for Max/Min Pelvis: ±3 mm Thresholds for Max/Min Head: ±6 mm Thresholds for Max/Min Pelvis: ±3 mm
Diff Max Head: Mean: 13.2 mm SD: 11.9 mm Diff Max Pelvis: Mean: –2.3 mm SD: 3.4 mm Diff Max Head: Mean: –5.4 mm SD: 6.2 mm Diff Max Pelvis: Mean: –0.6 mm SD: 2.7 mm
Diff Min Head: Mean: 51.3 mm SD: 16.1 mm Diff Min Pelvis: Mean: –4.5 mm SD: 4.8 mm Diff Min Head: Mean: –11.9 mm SD: 6.6 mm Diff Min Pelvis: Mean: 8.8 mm SD: 2.9 mm
Threshold for Total Diff Head: 8.5 mm Threshold for Total Diff Head: 8.5 mm
Total Diff Head (Vector Sum): 53.0 mm Total Diff Head (Vector Sum): 13.0 mm
Q Score (fore): R 53.0 Mid Q Score (hind): L 2.3 Push / L 4.5 Imp Q Score (fore): L 13.0 Imp Q Score (hind): L 0.6 Push / R 8.8 Imp
Figure 2.141. Lameness Locator® reports of multiple limb forelimb lameness. No compensatory lameness pattern explains this
lameness. Left report: Left hindlimb impact only, no pushoff lame- pattern. The best explanation of this type of multiple limb lameness is
ness, and contralateral right forelimb lameness. Right report: Right primary forelimb lameness and secondary hindlimb lameness or
hindlimb impact only, no pushoff lameness, and contralateral left primary hindlimb lameness and secondary forelimb lameness.
hindlimb lameness and primary hindlimb lameness type of multiple limb lameness had a 71% definitive
and secondary forelimb lameness. This type of multi­ diagnostic rate. Ultimately 61% of cases had only a
ple limb lameness had the lowest (54%) definitive forelimb diagnosis, with 27% being bilateral forelimb
diagnostic rate, with 75% ultimately having a diag­ lameness, only 3% with both a forelimb and a
nosis of only forelimb abnormality, with about 1 in 3 hindlimb diagnosis, 28% with a hindlimb only diag­
(31%) being bilateral, 11% that ultimately had a nosis, and less than 8% with a diagnosis of “other”
diagnosis in both a forelimb and a hindlimb, only (abnormality found but not in the limbs).
6% with an ultimate diagnosis in only a hindlimb,
and an (8%) “other” (diagnosis not in the limbs) Flexion Tests
diagnostic rate.
8. Forelimb lameness with contralateral hindlimb lame­ Lameness Locator® can be used to objectively quan­
ness that is decreased pushoff and ipsilateral hindlimb tify the effect of flexion tests. Reference ranges and con­
lameness that is decreased impact (Figure 2.142). fidence intervals established for trotting in a straight
This type occurred in about 7% of all multiple limb line and collecting at least 25 contiguous strides, how­
cases. It is easily explained by the second principle in ever, are not applicable. The effect of flexion tests is usu­
the “law of sides,” with contralateral hindlimb lack of ally dissipated after fewer (>25) numbers of strides, and
pushoff and ipsilateral hindlimb lack of impact. This the veterinarian usually evaluates the effects of flexion