Locomotion in degus on terrestrial substrates varying in orientation - implications for biomechanical constraints and gait selection.
To gain new insights into running gaits on sloped terrestrial substrates, metric and selected kinematic parameters of the common degu (Octodon degus) were examined. Individuals were filmed at their maximum voluntary running speed using a high-speed camera placed laterally to the terrestrial substrate varying in orientations from -30° to +30°, at 10° increments. Degus used trotting, lateral-sequence (LS) and diagonal-sequence (DS) running gaits at all substrate orientations. Trotting was observed across the whole speed range whereas DS running gaits occurred at significantly higher speeds than LS running gaits. Metric and kinematic changes on sloped substrates in degus paralleled those noted for most other mammals. However, the timing of metric and kinematic locomotor adjustments differed significantly between individual degus. In addition, most of these adjustments took place at 10° rather than 30° inclines and declines, indicating significant biomechanical demands even on slightly sloped terrestrial substrates. The results of this study suggest that DS and LS running gaits may represent an advantage in small to medium-sized mammals for counteracting some level of locomotor instability. Finally, changes in locomotor parameters of the forelimbs rather than the hindlimbs seem to play an important role in gait selection in small to medium-sized mammals.
Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, 120 Life Science Building, Athens, OH 45701, USA. Electronic address: schmidta@ohio.edu.
André
A
Schmidt
D000818:Animals; D001696:Biomechanical Phenomena; D005684:Gait / Q000502:physiology*; D008124:Locomotion / Q000502:physiology*; D008297:Male; D046329:Octodon / Q000033:anatomy & histology / Q000502:physiology*
Declines; Gait selection; Inclines; Octodon degus; Running gaits