Human Research


Human Running studies (with R. Kram-UC Berkeley)

  • what limits sprint speed on a curved track?
  • what is the metabolic cost of generating horizontal forces?
  • what are the biomechanical roles of gravity and inertia?

Basic studies: limb control during hopping

  • motor redundancy (use of joint neuromechanical redundancy)
  • compensation for joint loads (importance of the nature of loading)
  • targeted foot placement (use of motor redundancy with targeting)
  • rate-dependent control (leg control changes with rate of movement)

Extreme behaviors

  • brachiating gibbons (with J. Bertram-Cornell)
  • jumping vampire bats (with B. Schutt & J. Hermanson-Cornell)
  • elephant locomotion (supporting J. Hutchinson-Royal Vet. College)
  • waddling penguins (supporting T. Griffin & R. Kram-UC Berkeley)

Pathologies: lower leg amputation

  • gait (gait compensation with a lower-limb amputation)
  • gait initiation (control of gait initiation with a below-knee amputation)

Device development: orthoses

  • slafo (experimental tool for applying joint loads during locomotion)
  • aemgcfes (uses effected muscle’s emg to drive real-time control of fes)
  • the “bullfrog” (bioinspired energy harvesting afo)
  • exercise countermeasure for astronaut bone loss
  • first multi-axis instrumented (force-measuring) treadmill
  • 6-dof force-torque transducer for brachiation
  • force platform for jumping bats


Comparative Research


Basic studies

  • locomotor compensation after injury (limb function preserved over joint function in three mammal species)

 Extreme behaviors

  • single-limb stance in flamingos (behavioral and morphological measurements, with L. Ting-Emory/GT)
  • vaginal marking in golden hamsters (kinematics of scent-marking behavior, with A. Petrulis-GSU)

Device development

  • accurate rodent kinematics via high-speed x-ray video (optical kinematics methods show large errors due to skin movement)
  • hybrid isolated spinal cord-hindlimb preparation (spontaneous in vitro locomotion with biomechanics & electrophysiology, with S. Hochman-Emory)


Previous Thesis Projects


  • Robustness and hierarchical control of performance variables through coordination during human locomotion, Arick Auyang, 2010
  • Influencing motor behavior through constraint of lower limb motion, Chris Hovorka, 2015 
  • Biomechanics and electrophysiology of sensory regulation during locomotion in a novel in vitro spinal cord-hindlimb preparation, Heather Hayes, 2010
  • Force control during human bouncing gaits, Jasper Yen, 2011
  • Injury compensation reveals implicit goals that guide locomotor coordination, Jay Bauman, 2013
  • Adaptation of locomotor control in able and impaired human walking, Megan Toney, 2014