Summary
The objective was to determine whether the use of heel wedges is an appropriate treatment
for superficial digital flexor (SDF) tendinitis. The subjects were six warmblood horses
in which SDF tendinitis was induced in one forelimb using a collagenase model. The
stride characteristics were compared under four conditions: flat shoes; 6° heel wedge
following a one hour adaptation; 6° heel wedge following five days adaptation; and
one hour after reapplication of flat shoes. Videographic and force data were collected
for both forelimbs during the stance phase of the trot, and were combined with morphometric
measurements using an inverse dynamics method to calculate net joint moments and joint
powers at each of the joints of the forelimbs. Repeated measures ANOVA was used to
compare the stride variables across conditions in the lame limb and in the compensating
forelimb. Significant kinematic changes in response to the use of heel wedges were
confined to the coffin joint which was more flexed due to the more upright orientation
of the hoof segment. The onset of breakover was delayed with the hoof wedges. In the
compensating limb only, the use of heel wedges was associated with a shift of the
net joint moment to the dorsal side of the coffin joint during the first one third
of stance. Both forelimbs had significantly smaller peak palmar moments at the coffin
joint with heel wedges in the second half of stance, which appeared to be a mechanical
consequence of the more flexed position of the coffin joint. Tension was increased
in the extensor branches of the suspensory ligament and common digital extensor tendon
on the dorsal side, and reduced in the deep digital flexor tendon and its distal accessory
ligament on the palmar side. Less energy was absorbed across the coffin joint in both
limbs with heel wedges. The study did not reveal changes associated with the use of
heel wedges that could be interpreted as a reduction of the effects of lameness due
to SDF tendinitis.
The objective was to determine whether the application of 60 heel wedges was appropriate
for treating horses with superficial digital flexor (SDF) tendinitis. The significant
effects of the heel wedges affected the coffin joint and included a more flexed position
due to the more upright orientation of the hoof segment, a reduction in the peak palmar
moment and less energy absorption across the joint. Since these changes were confined
to the coffin joint, they were not interpreted as being beneficial in treating lameness
due to SDF tendinitis.
Keywords
Kinematics - kinetics - inverse dynamics - net joint moments - joint powers - farriery
