Objective—To develop and validate a novel instrumented
treadmill capable of determining vertical ground reaction forces of all 4 limbs simultaneously in
Sample Population—Data obtained while a horse
was walking and trotting on the treadmill.
Procedure—18 piezo-electric force transducers
were mounted between the treadmill frame and
supporting steel platform to measure the actual
forces at the corresponding bearing points. Each of
the 18 sensor forces is equal to the sum of the
unknown hoof forces weighted with the transfer
coefficients of the corresponding force application
points. The 4 force traces were calculated, solving at
each time point the resulting equation system, using
the Gaussian least-squares method. System validation
comprised the following tests: determination of
the survey accuracy of the positioning system,
determination of the natural frequencies of the system,
linearity test of the force transfer to the individual
sensors, determination of superimposed
forces with the treadmill-integrated force measuring
system (TiF) in a static configuration, and comparison
of vertical ground reaction forces determined
simultaneously by use of TiF and force shoes mounted
on the forelimbs of a horse.
Results—Comparison between static test loads and
TiF-calculated forces revealed deviations of < 1.4%. Force traces of TiF-calculated values and those recorded
by use of the force shoes were highly correlated ( r ≥ 0.998).
Conclusions and Clinical Relevance—This instrumented
treadmill allows a reliable assessment of load distribution and interlimb coordination in a short period
and, therefore, is suitable for use in experimental and clinical investigations. (Am J Vet Res 002;63:520–527).
Objective—To evaluate a modified posterior rhinomanometric method for clinical application in dogs.
Animals—15 healthy Beagles and 8 Bulldogs (4 healthy and 4 with respiratory problems).
Procedures—Rhinomanometry was performed 3 times within a 15-minute period in anesthetized dogs.Transnasal pressure (PNA) and nasal resistance (RNA) were determined by use of artificial airflow (adjusted for body weight) for inspiration (PNAin and RNAin, respectively) and expiration (PNAout and RNAout). Procedures were repeated for the Beagles 7 days later.
Results—For the Beagles, mean ± SD of PNAin for both days (0.162 ± 0.042 kPa) was significantly lower than PNAout (0.183 ± 0.053 kPa). Similarly, RNAin (1.47 ± 0.41 kPa/[L/s]) was significantly lower than RNAout (1.64 ± 0.46 kPa/[L/s]). Pairwise comparison of values for PNA and RNA for the 2 days revealed no significant difference. Repeatability of the method (estimated as within-day variation) for RNA was ± 0.19 kPa/(L/s), whereas variation between the days was ± 0.36 kPa/(L/s) for RNAin and ± 0.44 kPa/(L/s) for RNAout. The 4 clinically normal Bulldogs had RNA values ranging from 1.69 to 3.48 kPa/(L/s), whereas in the 4 Bulldogs with respiratory problems, RNA ranged from 9.83 to 20.27 kPa/(L/s).
Conclusions and Clinical Relevance—RNA is inversely dependent on body size and nonlinearly associated with airflow. We propose that RNA in dogs should be determined for airflows standardized on the basis of body size. The PNA and RNA in Beagles can be measured with sufficient repeatability for clinical use and nasal obstructions are detectable.
Objective—To evaluate the effects of shock wave
treatment on cutaneous nerve function, compared
with the effects of local nerve block and sedation.
Animals—18 clinically sound Swiss Warmbloods.
Procedure—Horses were randomly allocated to 3
groups and received different amounts and types
of shock waves (extracorporeal shock wave treatment
[ESWT] or radial pressure wave treatment
[RPWT]). Horses were sedated with xylazine and
levomethadone. Shock waves were applied to the
lateral palmar digital nerve at the level of the proximal
sesamoid bones on 1 forelimb. Skin sensitivity
was evaluated by means of an electrical stimulus
at the coronary band before and 5 minutes after
sedation and at 4, 24, and 48 hours after application
of ESWT or RPWT. On the contralateral forelimb,
skin sensitivity was tested before and 10
minutes after an abaxial sesamoid nerve block.
Results—No significant changes in skin sensitivity
were detected, regardless of the shock wave protocol
applied. Mean reaction thresholds after sedation
were more than twice the baseline thresholds. After
the abaxial sesamoid block, no reaction was recorded
in any of the horses.
Conclusions and Clinical Relevance—Application of
ESWT or RPWT to the palmar digital nerve had no
effect on cutaneous sensation distal to the treated
region for at least 2 days after application. The analgesic
effect of sedation on reaction to electrical stimuli
was distinct but varied among horses. (Am J Vet
OBJECTIVE To compare gait mechanics and limb loading in Icelandic horses tölting and trotting at equal speeds and estimate their impact on orthopedic health.
ANIMALS 12 orthopedically normal Icelandic horses.
PROCEDURES Kinetic and kinematic gait variables were simultaneously recorded as each horse was ridden at a tölt and trot on an instrumented treadmill at 3.4 m/s and 3.9 m/s. Differences between gaits were tested via 1-factor repeated-measures ANOVA.
RESULTS Horses had a higher stride rate and lower stride impulses at a tölt than at a trot. For forelimbs at a tölt, shorter relative stance duration resulted in higher peak vertical force (Fzpeak). Conversely, for hind limbs, longer relative stance duration resulted in lower Fzpeak. The higher head-neck position at a tölt versus trot caused no weight shift to the hind limbs, but a higher forehoof flight arc and lower proretraction movement were identified. Stance durations for forelimbs were briefer than for hind limbs at a tölt, and the inverse was observed at a trot. Minimal height of the horse's trunk at the point of Fzpeak of the respective limb suggested a spring-like mechanism for all limbs at a tölt. Hind limb measurements revealed no evidence of increased collection. Stride-to-stride limb timing varied more at a tölt than at a trot. At a trot, horses had brief or no suspension phases and a slightly 4-beated footfall rhythm was common. Post hoc energetic estimations revealed that tölting at the measured speeds was less advantageous than trotting.
CONCLUSIONS AND CLINICAL RELEVANCE High forelimb action in Icelandic horses and higher head-neck position at a tölt were associated with more restricted limb proretraction, higher Fzpeak, and faster force onset than at a trot. The impact of these differences on orthopedic health needs to be investigated more in detail.