Hopping and swimming in the leopard frog,Rana pipiens: I. Step cycles and kinematics

Section: Discussionmentioning

confidence: 99%

Hydrodynamics of surface swimming in leopard frogs (Rana pipiens)

Johansson

Lauder

2004

“…Maximum take-off velocities in K. maculata were slightly below average velocity reported in other frogs, whereas jump distance (scaled to SVL) was within the range reported for ranids but substantially lower than distances recorded in hylids ( Table 4). The proximal to distal pattern of joint opening observed during jumping in K. maculata has been widely reported among frogs Peters et al, 1996;Nauwelaerts and Aerts, 2003;Astley and Roberts, 2014;Wang et al, 2014) and is thought to maximize foot-to-ground contact time, prolong acceleration (so that maximum velocity is reached as late as possible) and aid in elastic energy pre-storage (Bobbert and van Ingen Schenau, 1988;van Ingen Schenau, 1989;Wang et al, 2014). Range of movement and maximum values of extension for the ankle, knee, hip and sacroiliac joints in K. maculata are similar to those reported in other species Peters et al, 1996;Nauwelaerts and Aerts, 2003;Astley and Roberts, 2014).…”

Section: Moment Arms and Kinematics Influence Jump Angle In K Maculatamentioning

confidence: 98%

“…Our results suggest that presumed anatomical/behavioural adaptations for walking in K. maculata do not affect jumping performance (but see , echoing studies that demonstrate limited evidence for a performance trade-off between jumping and swimming (Emerson and De Jongh, 1980;Peters et al, 1996;Nauwelaerts et al, 2007;Herrel et al, 2014;. It should be noted, however, that K. maculata is not morphologically specialized for walking to the degree found in other taxa (some microhylids, brevicepitines or hemisotids); thus, it is unknown how adaptation to walking may affect jumping performance more generally among frogs.…”

Section: Moment Arms and Kinematics Influence Jump Angle In K Maculatamentioning

confidence: 99%

Inverse dynamic modelling of jumping in the red-legged running frogKassina maculata

Porro

Collings

Eberhard

et al. 2017

Although the red-legged running frog, Kassina maculata, is secondarily a walker/runner, it retains the capacity for multiple locomotor modes, including jumping at a wide range of angles (nearly 70 deg). Using simultaneous hind limb kinematics and singlefoot ground reaction forces, we performed inverse dynamics analyses to calculate moment arms and torques about the hind limb joints during jumping at different angles in K. maculata. We show that forward thrust is generated primarily at the hip and ankle, while body elevation is primarily driven by the ankle. Steeper jumps are achieved by increased thrust at the hip and ankle and greater downward rotation of the distal limb segments. Because of its proximity to the GRF vector, knee posture appears to be important in controlling torque directions about this joint and, potentially, torque magnitudes at more distal joints. Other factors correlated with higher jump angles include increased body angle in the preparatory phase, faster joint openings and increased joint excursion, higher ventrally directed force, and greater acceleration and velocity. Finally, we demonstrate that jumping performance in K. maculata does not appear to be compromised by presumed adaptation to walking/ running. Our results provide new insights into how frogs engage in a wide range of locomotor behaviours and the multi-functionality of anuran limbs.

“…Several studies have shown that various anuran species prepare for high landing forces by moving their forelimbs anteriorly during the aerial phase of a jump to help brace for impact (Gillis et al, 2010;Griep et al, 2013;Nauwelaerts and Aerts, 2006;Peters et al, 1996). The degree to which the forelimbs are then able to decelerate the body varies markedly among species.…”

Section: Introductionmentioning

confidence: 99%

“…Yet, previous examinations of anuran forelimb kinematics have not addressed this question, instead emphasizing important features of the landing event itself (Griep et al, 2013;Nauwelaerts and Aerts, 2006), the role of pectoral girdle anatomy (Emerson, 1983;Griep et al, 2013) or more general kinematics of the hop cycle (Peters et al, 1996). Recent work by Azizi and Abbott (2013) suggests that elbow excursions change with hop distance in B. marinus.…”

Section: Introductionmentioning

confidence: 99%

Forelimb kinematics during hopping and landing in toads (Bufo marinus)

Cox

Gillis

2015

Coordinated landing in a variety of animals involves the re-positioning of limbs prior to impact to safely decelerate the body. However, limb kinematics strategies for landing vary considerably among species. For example, human legs are increasingly flexed before impact as drop height increases, while turkeys increasingly extend their legs before impact with increasing drop height. In anurans, landing typically involves the use of the forelimbs to decelerate the body after impact. Few detailed, quantitative descriptions of anuran forelimb kinematics during jumping exist and it is not known whether they prepare for larger landing forces by changing forelimb kinematics. In this study, we used high-speed video of 51 hops from five cane toads (Bufo marinus) to test the hypothesis that forelimb kinematics change predictably with distance. We measured excursions of the elbow (flexion/extension) and humerus (protraction/retraction and elevation/depression) throughout every hop. The results indicate that elbow and humeral excursions leading up to impact increase significantly with hop length, but do so without any change in the rate of movement. Instead, because the animal is in the air longer during longer hops, nearconstant velocity movements lead to the larger excursions. These larger excursions in elbow extension result in animals hitting the ground with more extended forelimbs in longer hops, which in turn allows animals to decelerate over a greater distance.