Energetic and kinematic consequences of weighting the distal limb

Abstract

Summary Reason for performing study: It is well known that adding a load to a horse's back increases its energetic costs of locomotion, but the magnitude of increase obtained by loading the most distal portion of limb has not been measured. Objectives: To measure oxygen consumption in horses with mass added to the back and hooves. Because such mass distribution alters inertial parameters of the limbs, kinematic measurements were made to quantify the magnitude of change in limb movement. Methods: Steady‐state oxygen consumption was measured in 6 horses with a load of 2.4 kg. The load was either carried on the back or distributed equally between the 4 limbs. Modified bell boots kept the mass at the level of P3. Horses trotted on a treadmill at speeds ranging from 2 to 5 m/sec (in 0.5 m/sec increments). High‐speed (250 Hz) digital images were recorded in a sagittal plane and the positions of retroreflective markers located on standard positions on the limbs were digitised for kinematic analysis. Results: Loading of the distal limbs produced a 6.7% increase in metabolic rate, an order of magnitude higher than when the mass was added over the back. Although the stride period was 2% longer in horses with loads on the distal limbs, time of contact and duty factor were not different. Distal limb loading increased the range of motion in hind‐but not forelimbs. Conclusions: The costs of swinging the limbs in the horse are considerable and the addition of weights to the distal limb can have a profound effect on not only the energetics of locomotion but also the kinematics, at least in the hindlimb. Potential relevance: The use of weighted shoes, intended to increase animation of the gait, increases the metabolic effort of performance horses a disproportionate amount. The additional mass also increases the joint range of motion and, potentially, the likelihood of injury.

Development of locomotor parameters of the flying pace of Icelandic Horses after application of weights to the palmar aspect of the hoof

“…Other studies concerning the influence of addition of weight to the distal limbs on the biomechanics of different gaits used considerably heavier loads on each limb, ranging 365 to 600g (Willemen et al 1994, Singleton et al 2003, Wickler et al 2004). In the present study, the added weights were chosen to be in coherence with the present rules for Icelandic Horse tournaments (FEIF 2011) in order to be able to provide information concerning the practiced use of palmarly added weights.…”

“…The length and duration of the stride and relative duration of stance and suspension phase were not altered. The addition of 600g to the distal part of all four limbs resulted in an elongation of the stride period in the trot on a treadmill, but no changes in time of contact or duty factor (Wickler et al 2004). The range of motion of the forelimbs of these horses was not influenced, that of the hindlimbs was increased by the weights.…”

Kinematics and Ground Reaction Force Determination: A Demonstration Quantifying Locomotor Abilities of Young Adult, Middle-aged, and Geriatric Rats

“…In fact, kinematics, ground reaction force determination, or both have been used in a variety of species such as elephants [33][34][35] , cattle 36 , horses [37][38][39][40] , dogs 4,[41][42][43][44][45] , cats 21,[46][47][48][49] , various rodents 3,8,50,51 , birds 4,[52][53][54][55] , and fish 56,57 (this list is by no means exhaustive). In the authors' experience, however, the use of mice is problematic given that mice are not easy to operantly condition to travel along a runway.…”

Influence of palmarly added weights on locomotor parameters of the tölt of Icelandic Horses and comparison with corresponding data of the flying pace

“…Furthermore, an earlier fatigue of the limbs and associated structures might occur through the higher metabolic costs of the added weight. The energetic consequences of weighting the distal limb where investigated (Wickler et al 2004) and an increase of 6.7 % of the metabolic rate was found after application of 600 g to the P3 region of all four limbs. These authors as well as others (Pecha et al 2011, Rumpler et al 2010) also assume a possible detrimental effect of the added weights on the musculoskeletal system and a higher risk of injury.…”

“…This might be due to a shift of the carriage of the whole body by the horse from the fore-to the hindlimbs, resulting in higher loading forces respectively higher forces acting on them. When comparing joint work and power in the fore-and hindlimbs of horses during the trot, it was noted that the forelimbs generally have a net braking force, whereas the hindlimbs display a net propulsive force (Dutto et al 2006) In a study looking into the energetic and kinematic effects of weights applied to the distal limb it was found that the range of motion only increased in the hind-but not in the forelimbs (Wickler et al 2004). Even though in that study all four limbs were loaded equally, the change in biomechanics could resemble those found in the present study.…”