Movement Lab - Publications
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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.
- 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
- 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
(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.
- 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.
- Matthew Handford and Manoj Srinivasan. Sideways
walking: preferred is slow, slow is optimal, and optimal
is expensive, Biology Letters, 10 (1), 20131006,
Journal link and Supplementary Information
Here is a webpage for the paper with videos, data, and key MATLAB programs.
- 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
See here for Media/Press articles on this paper.
Here is a webpage for the paper with further information, data, and programs.
- 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
Here's a PDF and a webpage for the paper with videos.
- 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.
- 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.
- Jennifer A. Perry and Manoj Srinivasan.
Walking with wider steps changes foot placement control gains, but does not improve linear stability.
In revision, Royal Society Open Science, 2016.
- 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.
- Matthew L. Handford and Manoj Srinivasan.
Energy-optimal human walking with feedback-controlled robotic prostheses: a computational study.
In review, 2016.
- Yang Wang and Manoj Srinivasan.
Factorized Poincare Maps: representation and system identification of deterministic and noise-driven dynamical systems near periodic orbits.
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