Objective—To determine whether kinematic changes
induced by heel pressure in horses differ from those
induced by toe pressure.
Animals—10 adult Quarter Horses.
Procedure—A shoe that applied pressure on the
cuneus ungulae (frog) or on the toe was used.
Kinematic analyses were performed before and after 2
levels of frog pressure and after 1 level of toe pressure.
Values for stride displacement and time and joint angles
were determined from horses trotting on a treadmill.
Results—The first level of frog pressure caused
decreases in metacarpophalangeal (fetlock) joint extension
during stance and increases in head vertical movement
and asymmetry. The second level of frog pressure
caused these changes but also caused decreases in
stride duration and carpal joint extension during stance
as well as increases in relative stance duration. Toe pressure
caused changes in these same variables but also
caused maximum extension of the fetlock joint to occur
before midstance, maximum hoof height to be closer to
midswing, and forelimb protraction to increase.
Conclusion and Clinical Relevance—Decreased fetlock
joint extension during stance and increased head
vertical movement and asymmetry are sensitive indicators
of forelimb lameness. Decreased stride duration,
increased relative stance duration, and decreased
carpal joint extension during stance are general but
insensitive indicators of forelimb lameness. Increased
forelimb protraction, hoof flight pattern with maximum
hoof height near midswing, and maximum fetlock joint
extension in cranial stance may be specific indicators
of lameness in the toe region. Observation of forelimb
movement may enable clinicians to differentiate lameness
of the heel from lameness of the toe. (Am J Vet Res 2000;61:612-619)
Objective—To identify hind limb and pelvic kinematic
variables that change in trotting horses after induced
lameness of the distal intertarsal and tarsometatarsal
joints and after subsequent intra-articular administration
Animals—8 clinically normal adult horses.
Procedure—Kinematic measurements were made
before and after transient endotoxin-induced lameness
of the distal intertarsal and tarsometatarsal joints and
after intra-articular administration of anesthetic.
Fourteen displacement and joint angle (metatarsophalangeal
[fetlock] and tarsal joints) measurements were
made on the right hind limb, sacrum, and the right and
left tubera coxae. Kinematic measurements were compared
by general linear models, using a repeated measures
ANOVA. Post hoc multiple comparisons between
treatments were evaluated with a Fisher least squared
difference test at α = 0.05.
Results—After lameness induction, fetlock and tarsal
joint extension during stance decreased, fetlock joint
flexion and hoof height during swing increased, limb protraction
decreased, and vertical excursion of the tubera
coxae became more asymmetric. After intra-articular
administration of anesthetic, limb protraction returned to
the degree seen before lameness, and vertical excursion
of the tubera coxae became more symmetric.
Conclusions and Clinical Relevance—Increased
length of hind limb protraction and symmetry of tubera
coxae vertical excursion are sensitive indicators of
improvement in tarsal joint lameness. When evaluating
changes in tarsal joint lameness, evaluating the horse
from the side (to assess limb protraction) is as important
as evaluating from the rear (to assess pelvic symmetry).
(Am J Vet Res 2000;61:1031–1036)