The impact of pelvic lateral rotation on hindlimb kinematics and stride length in the red-legged running frog, Kassina maculata. Issue 5 (8th May 2019)

• Record Type: Journal Article
• Authors: Collings, Amber J.; Porro, Laura B.; Hill, Cameron; Richards, Christopher T.
• Is Part Of: Royal Society open science. Volume 6:Issue 5(2019)
• Publication Date: 2019-05-08
• Subjects: frog -- three-dimensional kinematics -- locomotion -- pelvis -- Hyperoliidae; Science -- Periodicals; 500
• DOI: 10.1098/rsos.190060
• Languages: English
• ISSNs: 2054-5703

Abstract

Abstract : Some frog species, such as Kassina maculata (red-legged running frog), use an asynchronous walking/running gait as their primary locomotor mode. Prior comparative anatomy work has suggested that lateral rotation of the pelvis improves walking performance by increasing hindlimb stride length; however, this hypothesis has never been tested. Using non-invasive methods, experimental high-speed video data collected from eight animals were used to create two three-dimensional kinematic models. These models, each fixed to alternative local anatomical reference frames, were used to investigate the hypothesis that lateral rotation of the mobile ilio-sacral joint in the anuran pelvis plays a propulsive role in walking locomotion by increasing hindlimb stride length. All frogs used a walking gait (duty factor greater than 0.5) despite travelling over a range of speeds (0.04–0.23 m s −1 ). The hindlimb joint motions throughout a single stride were temporally synchronized with lateral rotation of the pelvis. The pelvis itself, on average, underwent an angular excursion of 12.71° (±4.39°) with respect to the body midline during lateral rotation. However, comparison between our two kinematic models demonstrated that lateral rotation of the pelvis only increases the cranio-caudal excursion of the hindlimb modestly. Thus, we propose that pelvic lateral rotation is not a stride length augmenting mechanism in K. maculata .