Universal Features in Panarthropod Inter-Limb Coordination during Forward Walking

Abstract

Terrestrial animals must often negotiate heterogeneous, varying environments. Accordingly, their locomotive strategies must adapt to a wide range of terrain, as well as to a range of speeds in order to accomplish different behavioral goals. Studies in Drosophila have found that inter-leg coordination patterns (ICPs) vary smoothly with walking speed, rather than switching between distinct gaits as in vertebrates (e.g., horses transitioning between trotting and galloping). Such a continuum of stepping patterns implies that separate neural controllers are not necessary for each observed ICP. Furthermore, the spectrum of Drosophila stepping patterns includes all canonical coordination patterns observed during forward walking in insects. This raises the exciting possibility that the controller in Drosophila is common to all insects, and perhaps more generally to panarthropod walkers. Here, we survey and collate data on leg kinematics and inter-leg coordination relationships during forward walking in a range of arthropod species, as well as include data from a recent behavioral investigation into the tardigrade Hypsibius exemplaris. Using this comparative dataset, we point to several functional and morphological features that are shared amongst panarthropods. The goal of the framework presented in this review is to emphasize the importance of comparative functional and morphological analyses in understanding the origins and diversification of walking in Panarthropoda.

Go thou to the ant: A comparative biomechanical analysis of locomotion in Hymenoptera (Hexapoda)

“…The short legs, already known to be a limiting factor ( e.g. , Reinhardt & Blickhan 2014; Nirody 2021; Wittlinger et al, 2007; Wahl et al, 2015), can reasonably explain the short stride length and narrow step width.…”

“…Other kinematic parameters are also largely proportional to running speed, such as stride length (Wahl et al, 2015; Wosnitza et al, 2013; Nirody, 2021), which describes the distance covered by a tarsus from the time of one touchdown to the next (Wahl et al, 2015; Pfeffer et al, 2019; Alexander, 2003) and may be visualized via spatial stride pattern (Wahl et al, 2015; Pfeffer et al, 2019; Tross et al, 2021). Spatial step patterns contain further information about the track or step width of the gait pattern, i.e.…”

Kinematic Modeling at the Ant Scale: Propagation of Model Parameter Uncertainties

“…Even if quadrupedal and hexapodal forms of locomotion have evolved independently ( Blickhan and Full, 1987 ), they present similarities. Both quadrupeds and hexapods can adapt their locomotive patterns according to their objective ( Hoyt and Taylor, 1981 ; Nirody, 2021 ). Like quadrupeds, hexapods exhibit a wide variety of locomotor strategies ( Nirody, 2021 ), e.g., walking, running, and jumping ( Musthak Ali et al, 1992 ) or even swimming ( Schultheiss and Guénard, 2021 ) and gliding hovering ( Yanoviak et al, 2005 ).…”

“…Both quadrupeds and hexapods can adapt their locomotive patterns according to their objective ( Hoyt and Taylor, 1981 ; Nirody, 2021 ). Like quadrupeds, hexapods exhibit a wide variety of locomotor strategies ( Nirody, 2021 ), e.g., walking, running, and jumping ( Musthak Ali et al, 1992 ) or even swimming ( Schultheiss and Guénard, 2021 ) and gliding hovering ( Yanoviak et al, 2005 ). As some quadrupeds do, insects change smoothly the inter-leg coordination patterns based on their locomotion speed ( Ambe et al, 2018 ).…”

The Smooth Transition From Many-Legged to Bipedal Locomotion—Gradual Leg Force Reduction and its Impact on Total Ground Reaction Forces, Body Dynamics and Gait Transitions

“…Blickhan and Full, 1987;Blickhan and Full, 1993;Alexander, 2003;Biewener, 2003;Komsuo glu et al, 2009;Lee, 2011;Weihmann et al, 2016) in particular when duty factors are not too high (but see the discussion section for the impact of deviations). Since ample time is available for the swing phases, in locomotor systems with many leg pairs, low duty factors can occur already at relatively low running speeds (Nirody, 2021), making symmetrical, one-humped single leg GRF traces the dominant pattern in a wide range of species.…”