Effects of shoeing on forelimb swing phase kinetics of trotting horses

Abstract

SummaryThe objective of this study was to compare swing phase phase kinetics in the equine forelimb under three shoeing conditions: unshod, flat shoes, eggbar shoes. Flat shoes and eggbar shoes were matched for weight. A 60 Hz video camera recorded a full trotting stride in the sagittal plane during three passes per horse for each shoeing condition. A general linear model ANOVA, treating the horse as a random variable was used to detect differences (p <0.05) between shoeing conditions. All of the joints showed significant differences in net joint moments and energy bursts, between the two shod conditions versus unshod, but differences were not evident between flat shoes and eggbar shoes. When the horses were shod the elbow flexors generated more energy in the early swing phase in order to overcome the increased inertia associated with the weight of the shoes; and the elbow extensors generated more energy in late swing phase to overcome the increased momentum of the shod hoof as it was swung forward. In the distal limb in the early swing phase, energy absorption increased on the extensor (dorsal) aspect, to control joint flexion, and in the late swing phase on the flexor (palmar) aspect to control forward motion and extension. It is concluded as a consequence of changing the inertial parameters of the hoof that the weight of the shoes altered the limb kinetics of trotting horses.

Energetic and kinematic consequences of weighting the distal limb

“…In some studies, addition of shoes increased animation of the forelimb (higher flight arc of the distal limb and a greater range of motion) in horses trotting on a treadmill at 4.0 m/sec (Willemen et al 1997). In a study comparing 6 horses trotting over ground at ~3.3 m/sec with and without shoes (365 g shoes), flight arc was not statistically different but timing of the peak of the flight arc occurred later in the shod horses (Singleton et al 2003). In the present study, both foreand hindlimb joints were measured and examined over a range of trotting speeds.…”

“…In a follow-up study using 3 shoeing conditions of the front hoof (unshod, flat shoes and egg bar shoes), additional mass on the hoof required that elbow flexors generated more energy in early swing and the elbow extensors generated more energy in late swing. In the distal limb, energy absorption increased with added mass during early swing (Singleton et al 2003). These changes in inertial parameters are key to linking energetics to swinging of the limbs.…”

Hindlimb response to tactile stimulation of the pastern and coronet

“…2001). Therefore, a correction for stimulator mass was applied as described by Singleton et al. (2003).…”

Abstracts from the: Fifth International Conference on Equine Locomotion

“…In contrast, studies on dogs (Steudel 1990) in which the limb mass was altered, demonstrated a relationship between limb mass and energy costs. The addition of distal forelimb mass increases flexion of the distal joints and height of the hoof flight arc (Willemen et al 1999), and the energy generation increases across the elbow joint to overcome the increased inertia (Singleton et al 2003).…”