Skip to main content

Research Repository

Advanced Search

All Outputs (61)

Investigation of models to estimate flight performance of gliding birds from wakes (2024)
Journal Article
Song, J., Chen, C., Cheney, J. A., Usherwood, J. R., & Bomphrey, R. J. (2024). Investigation of models to estimate flight performance of gliding birds from wakes. Physics of Fluids, 36(9), https://doi.org/10.1063/5.0226182

Mathematical models based on inviscid flow theory are effective at predicting the aerodynamic forces on large-scale aircraft. Avian flight, however, is characterized by smaller sizes, slower speeds, and increased influence of viscous effects associat... Read More about Investigation of models to estimate flight performance of gliding birds from wakes.

The functions of leg muscles, structures and mechanisms in running (2024)
Journal Article
Usherwood, J. (2024). The functions of leg muscles, structures and mechanisms in running. Biology Letters, 20(8), https://doi.org/10.1098/rsbl.2024.0260

The actions of the major human leg muscles are well established; however, the functions of these muscle actions during steady running remain unclear. Here, leg structures and mechanisms are considered in terms of their functions in meeting the task o... Read More about The functions of leg muscles, structures and mechanisms in running.

Dynamics of hinged wings in strong upward gusts (2023)
Journal Article
Stevenson, J., Cheney, J., Usherwood, J., Bomphrey, R., & Windsor, S. (2023). Dynamics of hinged wings in strong upward gusts. Royal Society Open Science, 10(5), https://doi.org/10.1098/rsos.221607

A bird's wings are articulated to its body via highly mobile shoulder joints. The joints confer an impressive range of motion, enabling the wings to make broad, sweeping movements that can modulate quite dramatically the production of aerodynamic loa... Read More about Dynamics of hinged wings in strong upward gusts.

Usherwood 27Jul2021 (2022)
Journal Article
Usherwood, J. (2022). Usherwood 27Jul2021. Journal of Experimental Biology, https://doi.org/10.1242/jeb.243254

Considerable attention has been given to the spring-like behaviour of stretching and recoiling tendons, and how this can reduce the work demanded from muscle for a given loss-return cycling of mechanical energy during high-speed locomotion. However,... Read More about Usherwood 27Jul2021.

Virtual manipulation of tail postures of a gliding barn owl (Tyto alba) demonstrates drag minimisation when gliding (2022)
Journal Article
Song, J., Cheney, J., Bomphrey, R., & Usherwood, J. (2023). Virtual manipulation of tail postures of a gliding barn owl (Tyto alba) demonstrates drag minimisation when gliding. Journal of the Royal Society, Interface, https://doi.org/10.1098/rsif.2021.0710

Aerodynamic functions of the avian tail have been studied previously using observations of bird flight, physical models in wind tunnels, theoretical modelling, and flow visualization. However, none of these approaches has provided rigorous, quantitat... Read More about Virtual manipulation of tail postures of a gliding barn owl (Tyto alba) demonstrates drag minimisation when gliding.

Raptor wing morphing with flight speed (2021)
Journal Article
Cheney, J., Stevenson, J., Durston, N., Maeda, M., Song, J., Megson-Smith, D., Windsor, S., Usherwood, J., & Bomphrey, R. (2021). Raptor wing morphing with flight speed. Journal of the Royal Society, Interface, Article 20210349. https://doi.org/10.1098/rsif.2021.0349

In gliding flight, birds morph their wings and tails to control their flight trajectory and speed. Using high-resolution videogrammetry, we reconstructed accurate and detailed 3D geometries of gliding flights for three raptors (barn owl, Tyto alba; t... Read More about Raptor wing morphing with flight speed.

Limb work and joint work minimization reveal an energetic benefit to the elbows-back, knees-forward limb design in parasagittal quadrupeds (2020)
Journal Article
Usherwood, J. R., & Granatosky, M. C. (2020). Limb work and joint work minimization reveal an energetic benefit to the elbows-back, knees-forward limb design in parasagittal quadrupeds. Proceedings of the Royal Society B: Biological Sciences, 287(1940), 20201517. https://doi.org/10.1098/rspb.2020.1517

Quadrupedal animal locomotion is energetically costly. We explore two forms of mechanical work that may be relevant in imposing these physiological demands. Limb work, due to the forces and velocities between the stance foot and the centre of mass, c... Read More about Limb work and joint work minimization reveal an energetic benefit to the elbows-back, knees-forward limb design in parasagittal quadrupeds.

Why are the fastest runners of intermediate size? Contrasting scaling of mechanical demands and muscle supply of work and power (2020)
Journal Article
Usherwood, J. R., & Gladman, N. W. (2020). Why are the fastest runners of intermediate size? Contrasting scaling of mechanical demands and muscle supply of work and power. Biology Letters, 16(10), 20200579

The fastest land animals are of intermediate size. Cheetah, antelope, greyhounds and racehorses have been measured running much faster than reported for elephants or elephant shrews. Can this be attributed to scaling of physical demands and explicit... Read More about Why are the fastest runners of intermediate size? Contrasting scaling of mechanical demands and muscle supply of work and power.

Artificial mass loading disrupts stable social order in pigeon dominance hierarchies (2020)
Journal Article
Portugal, S. J., Usherwood, J. R., White, C. R., Sankey, D. W. E., & Wilson, A. M. (2020). Artificial mass loading disrupts stable social order in pigeon dominance hierarchies. Biology Letters, 16(8), 20200468

Dominance hierarchies confer benefits to group members by decreasing the incidences of physical conflict, but may result in certain lower ranked individuals consistently missing out on access to resources. Here, we report a linear dominance hierarchy... Read More about Artificial mass loading disrupts stable social order in pigeon dominance hierarchies.

The Possibility of Zero Limb-Work Gaits in Sprawled and Parasagittal Quadrupeds: Insights from Linkages of the Industrial Revolution (2020)
Journal Article
Usherwood, J. R. (2020). The Possibility of Zero Limb-Work Gaits in Sprawled and Parasagittal Quadrupeds: Insights from Linkages of the Industrial Revolution. Integrative Organismal Biology, 2(1),

Animal legs are diverse, complex, and perform many roles. One defining requirement of legs is to facilitate terrestrial travel with some degree of economy. This could, theoretically, be achieved without loss of mechanical energy if the body could tak... Read More about The Possibility of Zero Limb-Work Gaits in Sprawled and Parasagittal Quadrupeds: Insights from Linkages of the Industrial Revolution.

High aerodynamic lift from the tail reduces drag in gliding raptors (2020)
Journal Article
Usherwood, J. R., Cheney, J. A., Song, J., Windsor, S. P., Stevenson, J. P. J., Dierksheide, U., Nila, A., & Bomphrey, R. J. (2020). High aerodynamic lift from the tail reduces drag in gliding raptors. Journal of Experimental Biology, 223, https://doi.org/10.1242/jeb.214809

Many functions have been postulated for the aerodynamic role of the avian tail during steady-state flight. By analogy with conventional aircraft, the tail might provide passive pitch stability if it produced very low or negative lift. Alternatively,... Read More about High aerodynamic lift from the tail reduces drag in gliding raptors.

Minimalist analogue robot discovers animal-like walking gaits (2019)
Journal Article
Smith, B. J. H., & Usherwood, J. R. (2019). Minimalist analogue robot discovers animal-like walking gaits. https://doi.org/10.1088/1748-3190/ab654e

Robots based on simplified or abstracted biomechanical concepts can be a useful tool for investigating how and why animals move the way they do. In this paper we present an extremely simple quadruped robot, which is able to walk with no form of softw... Read More about Minimalist analogue robot discovers animal-like walking gaits.

The scaling or ontogeny of human gait kinetics and walk-run transition: The implications of work vs. peak power minimization (2018)
Journal Article
Usherwood, J. R., Hubel, T. Y., Smith, B. J. H., Self Davies, Z. T., & Sobota, G. (2018). The scaling or ontogeny of human gait kinetics and walk-run transition: The implications of work vs. peak power minimization. Journal of Biomechanics, 81, 12-21. https://doi.org/10.1016/j.jbiomech.2018.09.004

A simple model is developed to find vertical force profiles and stance durations that minimize either limb mechanical work or peak power demands during bipedal locomotion. The model predicts that work minimization is achieved with a symmetrical verti... Read More about The scaling or ontogeny of human gait kinetics and walk-run transition: The implications of work vs. peak power minimization.

The grazing gait, and implications of toppling table geometry for primate footfall sequences (2018)
Journal Article
Usherwood, J. R., & Smith, B. J. H. (2018). The grazing gait, and implications of toppling table geometry for primate footfall sequences. Biology Letters, 14(5), https://doi.org/10.1098/rsbl.2018.0137

Many medium and large herbivores locomote forwards very slowly and intermittently when grazing. While the footfall order during grazing is the same as for walking, the relative fore–hind timing—phasing—is quite different. Extended periods of static s... Read More about The grazing gait, and implications of toppling table geometry for primate footfall sequences.

Work minimization accounts for footfall phasing in slow quadrupedal gaits (2017)
Journal Article
Usherwood, J. R., & Self Davies, Z. T. (2017). Work minimization accounts for footfall phasing in slow quadrupedal gaits. eLife, 6, e29495. https://doi.org/10.7554/eLife.29495.001

Quadrupeds, like most bipeds, tend to walk with an even left/right footfall timing. However, the phasing between hind and forelimbs shows considerable variation. Here, we account for this variation by modeling and explaining the influence of hind-for... Read More about Work minimization accounts for footfall phasing in slow quadrupedal gaits.

Physiological, aerodynamic and geometric constraints of flapping account for bird gaits, and bounding and flap-gliding flight strategies (2016)
Journal Article
Usherwood, J. R. (2016). Physiological, aerodynamic and geometric constraints of flapping account for bird gaits, and bounding and flap-gliding flight strategies. Journal of Theoretical Biology, 408, 42-52. https://doi.org/10.1016/j.jtbi.2016.07.003

Aerodynamically economical flight is steady and level. The high-amplitude flapping and bounding flight style of many small birds departs considerably from any aerodynamic or purely mechanical optimum. Further, many large birds adopt a flap-glide flig... Read More about Physiological, aerodynamic and geometric constraints of flapping account for bird gaits, and bounding and flap-gliding flight strategies.

Social density processes regulate the functioning and performance of foraging human teams (2015)
Journal Article
King, A. J., Myatt, J. P., Fuertbauer, I., Oesch, N., Dunbar, R. I. M., Sumner, S., Usherwood, J. R., Hailes, S., & Brown, M. R. (2015). Social density processes regulate the functioning and performance of foraging human teams. https://doi.org/10.1038/srep18260

Social density processes impact the activity and order of collective behaviours in a variety of biological systems. Much effort has been devoted to understanding how density of people affects collective human motion in the context of pedestrian flows... Read More about Social density processes regulate the functioning and performance of foraging human teams.

Children and adults minimise activated muscle volume by selecting gait parameters that balance gross mechanical power and work demands (2015)
Journal Article
Hubel, T. Y., & Usherwood, J. R. (2015). Children and adults minimise activated muscle volume by selecting gait parameters that balance gross mechanical power and work demands. Journal of Experimental Biology, 218(PT 18), 2830-2839. https://doi.org/10.1242/jeb.122135

Terrestrial locomotion on legs is energetically expensive. Compared with cycling, or with locomotion in swimming or flying animals, walking and running are highly uneconomical. Legged gaits that minimise mechanical work have previously been identifie... Read More about Children and adults minimise activated muscle volume by selecting gait parameters that balance gross mechanical power and work demands.