Concord Field Station

David Lee

Formerly a postdoctoral researcher at the Concord Field Station, David is now an Assistant Professor in the School of Life Sciences at University of Nevada, Las Vegas.

Research interests: Running quadrupeds are extraordinary dynamic systems capable of fast progression, large accelerations, climbing, descending and jumping in complex terrain. Evidence from the natural diversity of quadruped body design and locomotor performance, as well as lessons from attempts to engineer legged robots with animal-like running abilities, suggest that there is more to quadruped design than four generalized legs attached to a long body. My primary interests lie in the relationship between body design and running dynamics. I have focused on effects of mass distribution, limb length, and limb geometry during both steady and non-steady locomotion, combining experimental measurements with dynamic simulations. My current work examines individual joint dynamics in the context of whole-limb and whole-body dynamics using goats (rough-terrain specialists) and dogs (speed and endurance runners).

Recent publications: Lee, D. V., Stakebake, E. F., Walter, R. M. and Carrier, D. R. (2004) Effects of mass distribution on the mechanics of level trotting in dogs. J Exp Biol 207, 1715-28
Lee, D. V., Walter, R. M., Deban, S. M. and Carrier, D. R. (2001) Influence of increased rotational inertia on the turning performance of humans. J. Exp. Biol. 204, 3927-3934
Lee, D. V., Bertram, J. E. A. and Todhunter, R. J. (1999) Acceleration and balance in trotting dogs. J. Exp. Biol.202, 3565-3573

M. Polly McGuigan

Formerly a postdoctoral researcher at the Concord Field Station, Polly is now a lecturer in the Department of Sport and Exercise Science at the University of Bath in the UK.

Research interests: My research to date has focused on two main themes: objective biomechanical studies of lameness and its treatment in a clinical setting, and the varying role of muscles in locomotion. My work in this area ranges from the digital flexor muscles of the horse (which are capable of generating large forces in eccentric contraction and may be responsible for damping vibrations within the limb) to mechanisms of modulating power output in the avian pectoralis muscle. I am now focusing on how the role of muscle differs within an individual limb. Distal short-fibred muscles with long tendons contract isometrically for economical force production and tendon elastic energy savings whereas muscles with longer fibres, located more proximally in the limb, account for the majority of mechanical work modulation.

Recent publications: McGuigan, M.P. and Wilson, A.M. (2003) The effect of gait and digital muscle activation on limb compliance in the forelimb of the horse (Equus caballus) J. Exp. Biol. 206, 1325-1336
Wilson, A.M., McGuigan, M.P., Su, A and Bogert, A.J. van den (2001) Horses damp the spring in their step. Nature 414, 895-899
Wilson, A.M., McGuigan, M.P., Fouracre, L. and McMahon, L. (2001) The force and contact stress on the navicular bone during trot locomotion in sound horses and horses with navicular disease. Equine Vet. J. 33, 159-165
McGuigan, M.P. and Wilson, A.M. (2001) The effect of bilateral palmar digital nerve analgesia on the compressive force experienced by the navicular bone in horses with navicular disease. Equine Vet J. 33, 166-171

Monica A. Daley

Formerly a graduate student at the Concord Field Station, Monica is now a lecturer for the Structure and Motion Laboratory at the Royal Veterinary College in the UK.

Research interests: Animals move in an unpredictable environment where steady locomotion is rare. Although we can understand many aspects of steady locomotion through mechanics alone, the nature and timing of other behaviors, such as stabilization after a disturbance, depend on the control mechanisms involved. I am interested in how animals integrate the mechanics and control of movement. My research investigates how animals achieve dynamic stability during locomotion in the face of perturbations, using an integrative experimental approach including body, limb and muscle dynamics.

Recent publications:
Daley, M. and Goller, F. (2004) Tracheal length changes during zebra finch song and their possible role in upper vocal tract filtering. J. Neurobiology 59, 319-330.
Daley, M. A. and Biewener, A. A (2003) Muscle force-length dynamics during level versus incline locomotion: a comparison of in vivo performance of two guinea fowl ankle extensors. J. Exp. Biol. 206, 2941-2958.
Goller, F. and Daley, M. A. (2001) Novel motor gestures for phonation during inspiration enhance the acoustic complexity of birdsong. Proceedings: Biological Sciences 268(1483), 2301-2305.

Russell P. Main

Formerly a graduate student at the Concord Field Station, Russ is now an NRSA Post-doctoral Research Fellow in the Department of Mechanical Engineering at Cornell University.

Research interests: My research interests largely concern how bone geometry and microstructure change throughout ontogeny in relation to functional bone strain patterns in the limb bones of tetrapods. To investigate this, I am collecting in vivo bone strain data from three vertebrate taxa (goats, emu, monitor lizards) at numerous ontogenetic stages and comparing how the microstructure and cross-sectional geometry of the limb bones in each taxa reflect the measured ontogenetic strain patterns. One goal of this work is to be to draw correlates from these extant taxa regarding the structure/function relationship between bone shape/histology and in vivo strain patterns to the fossil bones of extinct taxa to reconstruct the general biomechanical environments of fossil limb bones.

Recent publications:
Main, R.P., A. de Ricqles, J.R. Horner, and K. Padian (in press) The evolution of thyreophoran dinosaur scutes: implications for plate function in stegosaurs. Paleobiology.
Griffin, T. M., R. P. Main, and C. T. Farley. (2004) Biomechanics of quadrupedal walking: how do four-legged animals achieve inverted pendulum-like movements? J. Exp. Biol. 207: 3545-3558.
Main, R. P. and A. A. Biewener. (2004) Ontogenetic patterns of limb loading, in vivo bone strains and growth in the goat radius. J. Exp. Biol. 207: 2577-2588.

Craig P. McGowan

Formerly a graduate student at the Concord Field Station, Craig is now an NRSA Post-doctoral Research Fellow working jointly in the Department of Mechanical Engineering at the University of Texas, Austin, and in the Department of Integrative Physiology at the University of Colorado, Boulder.

Research interests: My research interests are broadly concerned with evolution of the musculo-skeletal systems and their role in locomotion. My current research is focused on the mechanics of non-steady bipedal hopping in Macropods (the group containing kangaroos). I am particularly interested in exploring how specific muscle-tendon specializations for elastic energy storage affect the mechanics of maneuvering in uneven environments. To address these questions, I employ a combination of external measurement techniques and in vivo muscle recordings to assess the role of various muscles and muscle-tendon units in whole body locomotor mechanics.

Recent publications:
McGowan, C. P., Baudinette, R. V. and Biewener, A. A. (2004) Joint work and power associated with acceleration and deceleration in tammar wallbies (Macropus eugenii). J. Exp. Biol. In-press.
Biewener, A. A., McGowan, C. P., Card, G. M., and Baudinette, R.V. (2004) Dynamics of leg muscle function in tammar wallabies (M. eugenii) during level versus incline hopping. J. Exp. Biol. 207, 211-223.

Ty Hedrick

Formerly a graduate student at the Concord field station, Ty is now an Assistant Professor in the Department of Biology at the University of North Carolina at Chapel Hill.

Jim Usherwood

Formerly a postdoctoral researcher at the Concord field station, Jim is now working in the Structure and Motion Laboratory at The Royal Veterinary College.

Anna Ahn

Formerly a postdoctoral researcher at the Concord Field Station, Anna is now an Assistant Professor in the Department of Biology at Harvey Mudd College.

Gary B. Gillis

Formerly a postdoctoral researcher at the Concord field station, Gary is now an Associate Professor in the Department of Biology at Mt. Holyoke College in western Massachusetts.

Barbekka Hurtt

Formerly a postdoctoral researcher at the Concord Field Station, Barb is now an Assistant Professor in the Department of Natural Sciences at Shenedoah University.

Bret W. Tobalske

Formerly a postdoctoral researcher at the Concord field station, Bret is now an Associate Professor in the Department of Biology at the University of Portland, Oregon. 

Peter G. Weyand

Formerly a research associate at the Concord Field Station, Peter is now an Assistant Professor in Rice University's Department of Kinesiology in Houston, Texas.