Movement Lab - Publications


  1. A. Ruina, J.E.A. Bertram and Manoj Srinivasan. A collisional model of the energetic cost of support work qualitatively explains leg sequencing in walking and galloping, pseudo-elastic leg behavior in running and the walk-to-run transition. Journal of Theoretical Biology, 237, 170-192, 2005. PDF
  2. Manoj Srinivasan and A. Ruina. Computer optimization of a minimal biped model discovers walking and running. Nature, 439, 72-75, 2006. PDF -- Press coverage -- Webpage with more information
  3. Manoj Srinivasan and A. Ruina. Idealized walking and running gaits minimize work. Proceedings of the Royal Society A, 463, 2429-2446, 2007. PDF -- Press coverage
  4. Manoj Srinivasan and P. Holmes. How well can spring-mass-like telescoping leg models fit multi-pedal sagittal-plane locomotion data? Journal of Theoretical Biology, 255, 1-7, 2008. PDF
  5. Manoj Srinivasan and A. Ruina. Rocking and rolling: A can that appears to rock might actually roll. Physical Review E, 78, 066609, 2008. PDF -- Video of the experiment
  6. Manoj Srinivasan. Chaos in a soda can: Non-periodic rocking of upright cylinders with sensitive dependence on initial conditions. Mechanics Research Communications, 36, 722-727, 2009. PDF
  7. Manoj Srinivasan. Optimal speeds for walking and running, and walking on a moving walkway. Chaos: An Interdisciplinary Journal for Nonlinear Science (Focus Issue: Bipedal Locomotion -- from Robots to Humans), 19, 026112, 2009. PDF -- Press coverage
  8. Manoj Srinivasan and S. Walcott. [equal author contribution] Binding site models of friction due to the formation and rupture of bonds: State function formalism, force-velocity relations, response to slip velocity transients, and slip stability. Physical Review E, 80, 046124, 2009. PDF.
  9. Manoj Srinivasan. Fifteen observations on the structure of energy minimizing gaits in many simple biped models. J. Royal Society Interface, PDF with supplementary information, 8, 74-98, 2011. Journal link
  10. Leroy Long and Manoj Srinivasan. Walking, running and resting under time, distance, and speed constraints: Optimality of walk-run-rest mixtures, J. Royal Society Interface, vol. 10, 2013. Journal Link.
    (PDF with supplementary information). Here's a webpage for the paper with more information.
    This article enjoyed some press coverage, including making an eventual appearance on Saturday Night Live's Weekend Update with Seth Myers. See Media.
  11. Manoj Srinivasan, Yang Wang and Alison Sheets. People bouncing on trampolines: Dramatic energy transfer, a table-top Demonstration, complex dynamics and a zero sum game, PLOS ONE, 8 (11): e78645, 2013. PDF and HTML versions. Here is a webpage for the paper with videos and some MATLAB programs.
  12. Matthew Handford and Manoj Srinivasan. Sideways walking: preferred is slow, slow is optimal, and optimal is expensive, Biology Letters, 10 (1), 20131006, 2014. (Article PDF+Supplementary Information)
    Journal link and Supplementary Information
                Here is a webpage for the paper with videos, data, and key MATLAB programs.
  13. Yang Wang and Manoj Srinivasan. Stepping in the direction of the fall: the next foot placement can be predicted from current upper body state in steady-state walking, Biology Letters, 10, 20140405, 2014. Link to journal article.    Link to Data (Dryad).   Article PDF+Supplementary Information.
    See here for Media/Press articles on this paper.
    Here is a webpage for the paper with further information, data, and programs.
  14. Varun Joshi and Manoj Srinivasan. Walking on a moving surface: energy-optimal walking motions on a shaky bridge and a shaking treadmill can reduce energy costs below normal, Proceedings of the Royal Society A, 471, 20140662, 2015. Link to journal article. 
                Here's a PDF and a webpage for the paper with videos
  15. Nidhi Seethapathi and Manoj Srinivasan. The metabolic cost of changing walking speeds is significant, implies lower optimal speeds for shorter distances, and increases daily energy estimates. Biology Letters, 11, 20150486, 2015. Here's the Article PDF+Supplementary Appendix. Link to journal article. Link to Data (Dryad).
                Here is a webpage for the paper with videos and data.
  16. Matthew Handford and Manoj Srinivasan. Robotic lower limb prosthesis design through simultaneous computer optimizations of human and prosthesis costs. Article PDF + Supplementary Information, Nature Scientific Reports, 6, 19983, 2016.
    A webpage for the paper with videos and more information.
  17. Jennifer A. Perry and Manoj Srinivasan. Walking with wider steps changes foot placement control gains, but does not improve linear stability. Royal Society Open Science, 2016. Webpage for the paper + PDF Downloads + Data Download + Code Download.
  18. Matthew L. Handford and Manoj Srinivasan. Energy-optimal human walking with feedback-controlled robotic prostheses: a computational study. IEEE Transactions on Neural Systems and Rehabilitation Engineering, 26, 1773-1782, 2018. Webpage for the paper + PDF Downloads. PDF
  19. Varun Joshi and Manoj Srinivasan. Walking crowds on a shaky surface: Stable walkers discover Millennium Bridge oscillations with and without pedestrian synchrony. Biology Letters, accepted subject to minor revisions, 2018. Webpage for the paper + PDF Downloads.
  20. Geoff Brown and Manoj Srinivasan. Curvilinear locomotion: simple model explains human energetics and energy optimality explains some non-straight-line walking behavior. In revision, Journal of Royal Society Interface, 2016.
  21. Yang Wang and Manoj Srinivasan. Factorized Poincare Maps: representation and system identification of deterministic and noise-driven dynamical systems near periodic orbits. 2016.

Ph.D. thesis.

Manoj Srinivasan. Why walk and run: energetic costs and energetic optimality in simple mechanics-based models of a bipedal animal. Ph.D. thesis. Cornell University, Ithaca, NY, May 2006. PDF (1.1 MB)

If you like, you can also see the list of publications on google scholar.

Free software and presentation slides.

In 2010, I gave a basic tutorial on "Trajectory Optimization" at the Conference on Dynamic Walking, 2010, held at the MIT Media Lab. Here are the slides and the MATLAB codes that went with the tutorial. Comments and questions are welcome. For more details on the optimization methods, please refer to the Interface paper.