Different Modes Of Locomotion Research Articles

Kinematic analysis of swimming ontogeny in seabass (Dicentrarchus labrax)

Swimming has been investigated in multiple species, but few studies consider the establishment of swimming through ontogeny. This study describes the establishment of cyclical swimming in Dicentrachus labrax, a marine fish from cold, temperate waters. The data were compared with results from previous studies on two subtropical freshwater catfish species (Clarias gariepinus and Corydoras aeneus). The three species have different modes of locomotion each during their adult stage (anguilliform, subacarangiform and carangiform). The swimming of Dicentrarchus labrax was recorded with a high-speed video camera (500 fps) from 0 to 288 hours and from 960 to 2496 hours post-hatching. Three indices, i.e. coefficient of determination (r²), coefficient of variation (CV), and Strouhal number (St), were used to investigate the establishment and efficiency of swimming. Important differences in the timing of swimming establishment were observed between the seabass and the two catfish species. The two catfish species display a sine-shaped swimming mode immediately or soon after hatching, and the efficiency of movement substantially improves during the first days of life. For seabass, however, establishment of swimming is slower during the same developmental period. These differences may be related to a faster developmental rate in the catfishes that allows them to swim rapidly in an intermediate regime flow and to develop the required morphology to establish efficient movements earlier.

Versatile vacuum-powered artificial muscles through replaceable external reinforcements.

Soft pneumatic artificial muscles are a well actuation scheme in soft robotics due to its key features for robotic machines being safe, lightweight, and conformable. In this work, we present a versatile vacuum-powered artificial muscle (VPAM) with manually tunable output motion. We developed an artificial muscle that consists of a stack of air chambers that can use replaceable external reinforcements. Different modes of operation are achieved by assembling different reinforcements that constrain the output motion of the actuator during actuation. We designed replaceable external reinforcements to produce single motions such as twisting, bending, shearing and rotary. We then conducted a deformation and lifting force characterization for these motions. We demonstrated sophisticated motions and reusability of the artificial muscle in two soft machines with different modes of locomotion. Our results show that our VPAM is reusable and versatile producing a variety and sophisticated output motions if needed. This key feature specially benefits unpredicted workspaces that require a soft actuator that can be adjusted for other tasks. Our scheme has the potential to offer new strategies for locomotion in machines for underwater or terrestrial operation, and wearable devices with different modes of operation.

A comparison of odor plume-tracking behavior of walking and flying insects in different turbulent environments.

Many animals locate food, mates and territories by following plumes of attractive odors. There are clear differences in the structure of this plume-tracking behavior depending on whether an animal is flying, swimming, walking or crawling. These differences could arise from different control rules used by the central nervous system during these different modes of locomotion or one set of rules interacting with the different environments while walking on the surface versus flying or swimming. Flow speeds and turbulence that characterize the environments where walking and flying insects track plumes may alter the structure of odor plumes in an environment-specific way that results in the same control rules generating behaviors that appear quite different. We tested these ideas by challenging walking male cockroaches, Periplaneta americana, and flying male moths, Manduca sexta, to track plumes of their species' sex pheromones in low wind speeds characteristic of cockroach experimental environments, higher wind speeds characteristic of moth experimental environments, and conditions ranging from low to high turbulence. Introducing a turbulence-generating structure into the flow significantly improved the flying plume tracker's ability to locate the odor source, and changed the structure of the behavior of both flying and walking plume trackers. Our results support the idea that plume trackers moving slowly along the substrate may use the spatial distribution of odor, while faster moving flying plume trackers may use the timing of odor encounters to steer to locate the source.

Evaluating the 'cost of generating force' hypothesis across frequency in human running and hopping.

The volume of active muscle and duration of extensor muscle force well explain the associated metabolic energy expenditure across body mass and velocity during level-ground running and hopping. However, if these parameters fundamentally drive metabolic energy expenditure, then they should pertain to multiple modes of locomotion and provide a simple framework for relating biomechanics to metabolic energy expenditure in bouncing gaits. Therefore, we evaluated the ability of the 'cost of generating force' hypothesis to link biomechanics and metabolic energy expenditure during human running and hopping across step frequencies. We asked participants to run and hop at 85%, 92%, 100%, 108% and 115% of preferred running step frequency. We calculated changes in active muscle volume, duration of force production and metabolic energy expenditure. Overall, as step frequency increased, active muscle volume decreased as a result of postural changes via effective mechanical advantage (EMA) or duty factor. Accounting for changes in EMA and muscle volume better related to metabolic energy expenditure during running and hopping at different step frequencies than assuming a constant EMA and muscle volume. Thus, to ultimately develop muscle mechanics models that can explain metabolic energy expenditure across different modes of locomotion, we suggest more precise measures of muscle force production that include the effects of EMA.

What Actually Works for Activity Recognition in Scenarios with Significant Domain Shift: Lessons Learned from the 2019 and 2020 Sussex-Huawei Challenges.

From 2018 to 2021, the Sussex-Huawei Locomotion-Transportation Recognition Challenge presented different scenarios in which participants were tasked with recognizing eight different modes of locomotion and transportation using sensor data from smartphones. In 2019, the main challenge was using sensor data from one location to recognize activities with sensors in another location, while in the following year, the main challenge was using the sensor data of one person to recognize the activities of other persons. We use these two challenge scenarios as a framework in which to analyze the effectiveness of different components of a machine-learning pipeline for activity recognition. We show that: (i) selecting an appropriate (location-specific) portion of the available data for training can improve the F1 score by up to 10 percentage points (p. p.) compared to a more naive approach, (ii) separate models for human locomotion and for transportation in vehicles can yield an increase of roughly 1 p. p., (iii) using semi-supervised learning can, again, yield an increase of roughly 1 p. p., and (iv) temporal smoothing of predictions with Hidden Markov models, when applicable, can bring an improvement of almost 10 p. p. Our experiments also indicate that the usefulness of advanced feature selection techniques and clustering to create person-specific models is inconclusive and should be explored separately in each use-case.

Lacertoid tracks from the Botucatu Formation (Lower Cretaceous) with different locomotor behaviors: A new trackmaker with novel paleoecological implications

The Botucatu Formation (Paraná Basin) is an eolian deposit that represents an extensive paleoerg that existed in the south-central Gondwana during the Early Cretaceous. The fossil record of the unit is almost exclusively constituted of ichnofossils, including numerous tracks and burrows of vertebrates and invertebrates. The greatest trace fossil diversity of the Botucatu Formation is reported at the Ouro ichnosite, located in the Araraquara municipality region, São Paulo State, Brazil. This site comprises a faunal-rich setting of greater humidity in the ancient desert. In this work, a new footprint morphotype is reported for the Ouro ichnosite. Five trackways including tracks with an elongated anteroposterior axis associated with tail drag marks are described. The morphology of the autopodia and geometry of the trackways indicate an affinity with a lizard-like trackmaker. Furthermore, at least three different modes of locomotion were recognized: a typical walking gait, a pause-walking gait, and sideways drifting. The current report suggests Lepidosauria may have inhabited the ancient Botucatu desert, a group never reported before in this geological context. This finding expands the knowledge about the Botucatu Formation paleofauna and adds more complexity to its ecological network. Squamata and Sphenodontia are plausible candidates to have produced the described fossil tracks.

Locomotion of Sensor‐Integrated Soft Robotic Devices Inside Sub‐Millimeter Arteries with Impaired Flow Conditions

One of the grand challenges in interventional cardiology and neuroradiology is to minimize the operation time and risk of damage during catheterization. These two factors drastically increase if the target location resides in small and tortuous vessels. Flow‐driven microcatheters are capable of rapidly and safely navigating small arteries with complex anatomy. However, their navigation relies on proper perfusion, which is an important bottleneck in the treatment of pathologies that cause impaired flow conditions. This work introduces the first endovascular sensor‐integrated soft robotic device that navigates sub‐millimeter arteries by extracting propulsive power from external magnetic fields. To this end, a number of innovations are described in the design, actuation, and control of flexible magnetic structures. The device is capable of advancing inside vasculature in an automated fashion using an open‐loop control scheme. Onboard sensors enable the real‐time monitoring of flow conditions, and autonomous switching between different modes of locomotion. The potential of the presented technology for minimally invasive diagnosis and therapy is demonstrated by achieving navigation inside coronary arteries of an ex vivo porcine heart under fluoroscopic guidance.

Muscular adaptations in swimming scale worms (Polynoidae, Annelida).

Annelids are predominantly found along with the seafloor, but over time have colonized a vast diversity of habitats, such as the water column, where different modes of locomotion are necessary. Yet, little is known about their potential muscular adaptation to the continuous swimming behaviour required in the water column. The musculature and motility were examined for five scale worm species of Polynoidae (Aphroditiformia, Annelida) found in shallow waters, deep sea or caves and which exhibit crawling, occasional swimming or continuous swimming, respectively. Their parapodial musculature was reconstructed using microCT and computational three-dimensional analyses, and the muscular functions were interpreted from video recordings of their locomotion. Since most benthic scale worms are able to swim for short distances using body and parapodial muscle movements, suitable musculature for swimming is already present. Our results indicate that rather than rearrangements or addition of muscles, a shift to a pelagic lifestyle is mainly accompanied by structural loss of muscle bundles and density, as well as elongation of extrinsic dorsal and ventral parapodial muscles. Our study documents clear differences in locomotion and musculature among closely related annelids with different lifestyles as well as points to myoanatomical adaptations for accessing the water column.

An Adaptive Control for the Path Tracking of an Active Leg Prosthesis

This paper presents an adaptive fuzzy-PID control strategy applied to an active lower limb prosthesis for trajectories tracking in normal walking, stairs climbing, and stairs descent. Trying to imitate a natural human limb, the prosthesis design challenges rehabilitating amputees to resume normal activities. A dynamic model of an ankle-knee active prosthesis is developed without ground reaction in a first case and introduces ground effect in a second one to ameliorate prothesis performances. The obtained models are used to synthesize a control strategy based on TS fuzzy concepts and PID control to reproduce human lower limb behavior in a normal gait and climb and descent of stairs. The RSME errors are calculated to evaluate and compare the various results performances and eventually show the capacity of the proposed control with ground reaction impact on trajectory tracking. The RMSE values obtained for the four outputs of the fuzzy controller are very small for the different modes of locomotion. Moreover, they become weaker when the ground reaction forces are added to the model to show the role of these forces for the body equilibrium maintaining during the gait cycle. The developed approach ensured good trajectories tracking compared to a healthy leg even in presence of disturbances.

Does aging cause joint mechanics redistribution during squat jumping?

Regarding physiological changes of aging process, several studies have highlighted progressive biomechanical adaptations of the lower limbs across different modes of locomotion and intensities (i.e...

Mechanics of locomotion of a double screw crawling robot

This paper analyzes the locomotion of a double screw-like robot composed of a right hand screw and a left hand screw attached via a rotating motor. Since the screws rotate in opposite directions, both screws produce propulsion in the same direction to advance. The advantage of this mechanism is that it can be used to crawl over deformable surfaces such as inside biological vessels and in granular media. We first develop a general analytical model of this double screw-like motion and describe its different modes of locomotion (raising-raising, raising-lowering, lowering-raising, lowering-lowering). We then use the model to determine the speed and forces acting on the robot as a function of the rotation speed, the screw geometry such as the diameter of the screw and its pitch, and the friction coefficient of the surface. The model is then used to evaluate the energy consumption of the locomotion and motor torques. The findings show that the surface forces acting on the two screws vary significantly if the coefficients of friction on each are different. The numerous new singular cases in which the screw forces can become infinite are discussed.

Quantifying morphological adaptations using direct measurements: The carnivoran appendicular skeleton as a case study.

Here, I study whether locomotor adaptations can be detected in limb bones using a univariate approach, and whether those results are affected by size and/or shared evolutionary history. Ultimately, it tests whether classical papers on locomotor adaptations should be trusted. To do that, I analyzed the effect of several factors (size, taxonomic group, and locomotor habit) on limb bone morphology using a set of 43 measurements of the scapula, long bones, and calcaneus, of 435 specimens belonging to 143 carnivoran species. Size was the main factor affecting limb morphology. Size-corrected analyses revealed artifactual differences between various locomotion-related categories in the analyses of raw data. Additionally, several between-group differences were new to the size-corrected analyses, suggesting that they were masked by the size-effect. Phylogeny had also an important effect, although it only became apparent after removing the effect of size, probably due to the strong covariation of both factors. Regarding locomotor adaptations, locomotor type was used to represent locomotor specialization, and utilized habitat as an indicator of the capacity to adopt different modes of locomotion (running, swimming, climbing, and digging) and thus maximize resource exploitation by being capable of navigating all the substrates in the habitat they use. Locomotor type produced better results than utilized habitat, suggesting that carnivorans use locomotor specialization to minimize locomotion costs. The characteristic limb bone morphology for each locomotor type studied is described, including several adaptations and trends that are novel to the present study. Finally, the results presented here support the hypothesis of a "viverrid-like", forest-dwelling carnivoran ancestor, either arboreal or terrestrial.

Eugenia Chiappe

Eugenia Chiappe

Biomechanical properties of anuran long bones: correlations with locomotor modes and habitat use

Long bones are subjected to mechanical loads during locomotion that will influence their biomechanical properties through a feedback mechanism (the bone mechanostat). This mechanism adapts the spatial distribution of the mineralized tissue to resist compression, bending and torsion. Among vertebrates, anurans represent an excellent group to study long bone properties because they vary widely in locomotor modes and habitat use, which enforce different skeletal loadings. In this study, we hypothesized that (a) the cortical bone mass, density and design of anuran femur and tibiofibula would reflect the mechanical influences of the different locomotor modes and habitat use, and (b) the relationships between the architectural efficiency of cortical design (cross-sectional moments of inertia) and the intrinsic stiffness of cortical tissue [cortical mineral density; the 'distribution/quality' (d/q) relationship] would describe some inter-specific differences in the efficiency of the bone mechanostat to improve bone design under different mechanical loads. To test this hypothesis, we determined tomographic (peripheral quantitative computed tomography) indicators of bone mass, mineralization, and design along the femur and tibiofibula of four anuran species with different modes of locomotion and use of habitat. We found inter-specific differences in all measures between the distal and proximal ends and mid-diaphysis of the bones. In general, terrestrial-hopper species had the highest values. Arboreal-walker species had the lowest values for all variables except for cortical bone mineral density, which was lowest in aquatic-swimmer species. The d/q relationships showed similar responses of bone modeling as a function of cortical stiffness for aquatic and arboreal species, whereas terrestrial-hoppers had higher values for moments of inertia regardless of the tissue compliance to be deformed. These results provide new evidence regarding the significant role of movement and habitat use in addition to the biomechanical properties of long bones within a morpho-functional and comparative context in anuran species.

An investigation to identify the thrust in flapping and undulatory motion of smart Timoshenko beam

In this paper, a computational approach to investigate the feasibility of using Smart Timoshenko beam (STB) for underwater locomotion is presented. The main objective of the current study is to understand different thrust producing mechanisms, namely flapping and undulatory modes of locomotion and to identify the critical parameters, such as body length, flexural stiffness and tail beat frequency affecting the locomotion. The thrust for different modes of locomotion with a variation in Young’s modulus and moment of inertia for the STB has been calculated. The results will help improve the understanding of thrust generation in both flapping and undulatory modes which are essential in the design and development of the bio-inspired robotic systems for underwater locomotion.

Angles and waves: intervertebral joint angles and axial kinematics of limbed lizards, limbless lizards, and snakes

Segmentation gives rise to the anterior-posterior axis in many animals, and in vertebrates this axis comprises serially arranged vertebrae. Modifications to the vertebral column abound, and a recurring, but functionally understudied, change is the elongation of the body through the addition and/or elongation of vertebrae. Here, we compared the vertebral and axial kinematics of the robustly limbed Fire skink (Riopa fernandi) representing the ancestral form, the limbless European glass lizard (Ophisaurus apodus), and the Northern water snake (Nerodia sipedon). We induced these animals to traverse through channels and peg arrays of varied widths and densities, respectively, using high-speed X-ray and light video. We found that even though the snake had substantially more and shorter vertebrae than either lizard, intervertebral joint angles did not differ between species in most treatment levels. All three species decreased the amplitude and wavelength of their undulations as channels narrowed and the lizard species increased wave frequency in narrower channels. In peg arrays, both lizard species decreased wave amplitude, while the snake showed no differences. All three species maintained similar wavelengths and frequencies as peg density increased in most cases. Our results suggest that amplitude is decoupled from wavelength and frequency in all three focal taxa. The combination of musculoskeletal differences and the decoupling of axial kinematic traits likely facilitates the formation of different undulatory waves, thereby allowing limbless species to adopt different modes of locomotion.

Multi-material Additive Manufacturing of Functional Soft Robot

The field of soft robotics has a lot of potential in various in-vivo bio-applications. However, there are several challenges in developing untethered soft robots including ease of fabrication, efficient actuation system and multiple integrated functionalities. This study proposes a fully 3D printed, monolithic soft robot capable of linear and turning locomotion. This multi-modal, multi-material soft robot has a compliant body structure made of magnetic particle-polymer composites and can be 3D printed directly from a digital computer model. The locally programmed magnetic material composition in the posterior and anterior legs allows untethered magnetic actuation. The robot has 3 degrees of freedom and is capable of bi-axial bending in xy plane and z directions. This paper presents design and fabrication process of the soft robot with the novel magnetic field assisted projection stereolithography (M-PSL) technique. The magnetic torque on the robot body during turning locomotion is also measured experimentally and compared with theoretical prediction. Additionally, a controlled dummy drug delivery application in model human stomach and lung is demonstrated to showcase the multi-functionality of the soft robot. A uniquely designed, magnetically controlled drug carrier reservoir is integrated into the anterior leg of the soft robot. This reservoir can hold the liquid drug during locomotion and releases the drug once the robot arrives at the targeted location. With different modes of locomotion and high bending capability, the robot is able to maneuver in confined spaces that represent the inside of human stomach and lungs.

Selection for longer limbs in mice increases bone stiffness and brittleness, but does not alter bending strength.

The ability of a bone to withstand loads depends on its structural and material properties. These tend to differ among species with different modes of locomotion, reflecting their unique loading patterns. The evolution of derived limb morphologies, such as the long limbs associated with jumping, may compromise overall bone strength. We evaluated bone mechanical properties in the Longshanks mouse, which was selectively bred for increased tibia length relative to body mass. We combined analyses of 3D shape and cross-sectional geometry of the tibia, with mechanical testing and bone composition assays, to compare bone strength, elastic properties and mineral composition in Longshanks mice and randomly bred controls. Our data show that, despite being more slender, cortical geometry and predicted bending strength of the Longshanks tibia were similar to controls. In whole bone bending tests, measures of bone bending strength were similar across groups; however, Longshanks tibiae were significantly more rigid, more brittle, and required less than half the energy to fracture. Tissue-level elastic properties were also altered in Longshanks mice, but the bones did not differ from the control in water content, ash content or density. These results indicate that while Longshanks bones are as strong as control tibiae, selection for increased tibia length has altered its elastic properties, possibly through changes in organic bony matrix composition. We conclude that selection for certain limb morphologies, and/or selection for rapid skeletal growth, can lead to tissue-level changes that can increase the risk of skeletal fracture, which in turn may favor the correlated evolution of compensatory mechanisms to mitigate increased fracture risk, such as delayed skeletal maturity.

Principles Governing Locomotion in Vertebrates: Lessons From Zebrafish.

Locomotor behaviors are critical for survival and enable animals to navigate their environment, find food and evade predators. The circuits in the brain and spinal cord that initiate and maintain such different modes of locomotion in vertebrates have been studied in numerous species for over a century. In recent decades, the zebrafish has emerged as one of the main model systems for the study of locomotion, owing to its experimental amenability, and work in zebrafish has revealed numerous new insights into locomotor circuit function. Here, we review the literature that has led to our current understanding of the neural circuits controlling swimming and escape in zebrafish. We highlight recent studies that have enriched our comprehension of key topics, such as the interactions between premotor excitatory interneurons (INs) and motoneurons (MNs), supraspinal and spinal circuits that coordinate escape maneuvers, and developmental changes in overall circuit composition. We also discuss roles for neuromodulators and sensory inputs in modifying the relative strengths of constituent circuit components to provide flexibility in zebrafish behavior, allowing the animal to accommodate changes in the environment. We aim to provide a coherent framework for understanding the circuitry in the brain and spinal cord of zebrafish that allows the animal to flexibly transition between different speeds, and modes, of locomotion.

A Hardware and Software Modular Robot for the Agricultural Domain

In order to take full potential of robots in the agriculture, there is a need for robots that can operate across different domains and infrastructure. Agriculture is extremely diverse and no two farms are the same, so robots need to be able to adapt to a wide variety of farm layouts. There are several reasons for this. Firstly, there is great variation in the way the robot needs to loco mote, for example in muddy fields, concrete floors, grassland, or rails, just to mention a few. Secondly, spacing between the plants vary, so the size of the robots also needs to be adjustable depending on the farm layout as some farms can only fit smaller robots while other farms need larger robots for more efficient operation. In this paper, we therefore present a completely modular robot that can be configured to operate in all these environments. The robot can be assembled to different modes of locomotion and the size can be changed depending on the farm specifications. In addition, the robot software is developed so that it automatically takes the shape and the size of the robot into account in the kinematics and control.