The effect of substrate compliance on the biomechanics of gibbon leaps

Abstract

SUMMARYThe storage and recovery of elastic strain energy in the musculoskeletal systems of locomoting animals has been extensively studied, yet the external environment represents a second potentially useful energy store that has often been neglected. Recent studies have highlighted the ability of orangutans to usefully recover energy from swaying trees to minimise the cost of gap crossing. Although mechanically similar mechanisms have been hypothesised for wild leaping primates, to date no such energy recovery mechanisms have been demonstrated biomechanically in leapers. We used a setup consisting of a forceplate and two high-speed video cameras to conduct a biomechanical analysis of captive gibbons leaping from stiff and compliant poles. We found that the gibbons minimised pole deflection by using different leaping strategies. Two leap types were used: slower orthograde leaps and more rapid pronograde leaps. The slower leaps used a wider hip joint excursion to negate the downward movement of the pole, using more impulse to power the leap, but with no increase in work done on the centre of mass. Greater hip excursion also minimised the effective leap distance during orthograde leaps. The more rapid leaps conversely applied peak force earlier in stance where the pole was effectively stiffer, minimising deflection and potential energy loss. Neither leap type appeared to usefully recover energy from the pole to increase leap performance, but the gibbons demonstrated an ability to best adapt their leap biomechanics to counter the negative effects of the compliant pole.

Total recoil: perch compliance alters jumping performance and kinematics in green anole lizards (Anolis carolinensis)

“…Because these perturbations can be energetically challenging and cause locomotor instability, their effects have been studied across a range of taxa, including cockroaches (Sponberg and Full, 2008), lizards (Korff and McHenry, 2011), turkeys (Gabaldón et al, 2004), fish (Webb and Cotel, 2010), gibbons (Channon et al, 2011) and humans (Moritz and Farley, 2003). In environments where these perturbations are common, animals often evolve behavioral means of compensating for the impacts on locomotion.…”

“…In environments where these perturbations are common, animals often evolve behavioral means of compensating for the impacts on locomotion. For example, cockroaches run more quickly to offset the effects of rough terrain (Sponberg and Full, 2008) and, as mentioned above, gibbons use low-power jumps to compensate for the effects of perch compliance (Channon et al, 2011). Indeed, one of the themes from this body of work is the remarkable ability of animals to overcome quite formidable natural obstacles through morphological and behavioral specializations.…”

“…If an animal is able to take advantage of the kinetic energy stored in the perch, the animal could use the perch as a springboard to propel itself, offsetting the initial energy loss. However, the use of perches as a springboard during jumping has thus far only been seen in humans (Channon et al, 2011). If a compliant perch is not used as a springboard, loss of energy to the perch could have marked effects on an animal's locomotion and behavior by decreasing the distance or speed at which the animal is able to jump.…”

“…Thus far, research on the effects of perch compliance on jumping has been restricted to a few studies of primates and birds (Bonser et al, 1999;Channon et al, 2011;Crompton et al, 1993). These authors found that in laboratory jumping trials, common starlings (Sturnus vulgaris) do not compensate for the loss of energy due to a compliant perch, whereas in contrast, white-cheeked gibbons [Hylobates (Nomascus) leucogenys] minimize the effects of compliance by using low-power jumps to limit perch deflection.…”

The role of hind limb tendons in gibbon locomotion: springs or strings?

“…Available kinematic and kinetic data from previous studies of bipedal locomotion (Vereecke and Aerts, 2008;Vereecke et al, 2006) and leaping (Channon et al, 2010a;Channon et al, 2011;Channon et al, 2012) in gibbons were used to investigate the role of the Achilles and patellar tendon during locomotion.…”