Joint work and power for both the forelimb and hindlimb during trotting in the horse

Abstract

SUMMARY The net work of the limbs during constant speed over level ground should be zero. However, the partitioning of negative and positive work between the fore- and hindlimbs of a quadruped is not likely to be equal because the forelimb produces a net braking force while the hindlimb produces a net propulsive force. It was hypothesized that the forelimb would do net negative work while the hindlimb did net positive work during trotting in the horse. Because vertical and horizontal impulses remain unchanged across speeds it was hypothesized that net work of both limbs would be independent of speed. Additionally because the major mass of limb musculature is located proximally,it was hypothesized that proximal joints would do more work than distal joints. Kinetic and kinematic analysis were combined using inverse dynamics to calculate work and power for each joint of horses trotting at between 2.5 and 5.0 m s–1. Work done by the hindlimb was indeed positive (consistently 0.34 J kg–1 across all speeds), but, contrary to our hypothesis, net work by the forelimb was essentially zero (but also independent of trotting speed). The zero net work of the forelimb may be the consequence of our not being able to account, experimentally, for the negative work done by the extrinsic muscles connecting the scapula and the thorax. The distal three joints of both limbs behaved elastically with a period of energy absorption followed by energy return. Proximal forelimb joints (elbow and shoulder) did no net work, because there was very little movement of the elbow and shoulder during the portion of stance when an extensor moment was greatest. Of the two proximal hindlimb joints, the hip did positive work during the stride,generating energy almost throughout stance. The knee did some work, but like the forelimb proximal joints, had little movement during the middle of stance when the flexion moment was the greatest, probably serving to allow the efficient transmission of energy from the hip musculature to the ground.

Muscle Fiber Population and Biochemical Properties of Whole Body Muscles in Thoroughbred Horses

“…2). This result supports the hypothesis that the forelimb muscles play a less propulsive role than hind limbs during daily activities (Niki et al, 1984;Merkens et al, 1993;Payne et al, 2004;Dutto et al, 2004Dutto et al, , 2006. Second, we found that the muscle fiber type populations in the thoracic and trunk portion were similar to those in the hindlimb portion.…”

“…It has been hypothesized that the hindlimb produces a net propulsive force, whereas the forelimb produces a net braking force in horse trotting at a constant speed (Merkens et al, 1993;Dutto et al, 2004). The previous studies demonstrated, using a combination of kinetic and kinematic analysis, that the major functions of forelimb and hindlimb muscles were antigravity and propulsive force production, respectively (Niki et al, 1984;Dutto et al, 2006). In addition, the horse muscles of the shoulder girdle, the suspending forelimb from the trunk anatomically, have a suitable structure for generating antigravity force (Payne et al, 2004).…”

Modulation of joint moments and work in the goat hindlimb with locomotor speed and surface grade

“…Averaged moments for the goats calculated on the level runway (Fig.3) are qualitatively similar to the moments reported previously for horses (e.g. Dutto et al, 2006) and dogs (e.g. Colborne et al, 2005;Colborne et al, 2006) trotting on level surfaces.…”

Modulation of work and power by the human lower-limb joints with increasing steady-state locomotion speed

“…It is interesting to compare our data for human running with equivalent data from studies that have investigated the effect of increasing trotting and/or galloping speeds on hindlimb joint mechanics for quadrupedal terrestrials, such as horses (Clayton et al, 2002;Dutto et al, 2006), goats (Arnold et al, 2013) and dogs (Colborne et al, 2006). While the mechanical behavior of a distal joint such as the ankle (or tarsus) is similar for quadrupeds and humans (i.e.…”