Massachusetts Institute of Technology
Sign in | Create Account

Dynamic Walking 2010. Greg Sawicki. Mechanics and control of a compliant muscle-tendon during cyclic contractions

Compliant mechanical behavior of the lower-limb can capture the basic dynamics of stable walking and running across a range of speeds, but the neuromechanical mechanisms responsible for robust, spring-like limb dynamics are not entirely clear. In order for a compliant muscle-tendon unit to behave similar to an elastic spring, the mechanics of active (muscle fascicles) and passive (series-elastic tendon and aponeurosis) tissues must be appropriately coordinated (i.e. ‘tuned’) within the movement cycle. This ‘tuning’ involves adjusting the pattern of muscle activation to modulate muscle force/stiffness output (via intrinsic force-length and force velocity properties) in order to match the loading profile imposed by the environment through series elastic structures within the muscle-tendon unit. Using bullfrog plantaris muscle-tendon, a servo-controlled muscle ergometer and sonomicrometry, we have developed a novel experimental framework to study the neuromechanics of a compliant muscle -tendon unit in vitro. In our initial experiments we employed classical work-loop techniques to understand how the feedforward (i.e. open-loop) muscle activation pattern (timing, magnitude and duration of stimulation) influences muscle-tendon unit net work output and internal energy exchange between muscle fascicles and series-elastic tissues. First I will present results demonstrating conditions that lead to ‘tuned’ elastic behavior of a compliant muscle-tendon unit. Then I will discuss plans to extend our framework and address the relative roles of neural feedback (length and/or force) and muscle-tendon architecture in stabilizing perturbations to steady-state, ‘tuned’ elastic cycles.

Comments (0)

It looks like no one has posted a comment yet. You can be the first!

You need to log in, in order to post comments. If you don’t have an account yet, sign up now!

Dynamic Walking 2010

Dynamic Walking 2010

Category: Education | Updated 4 years ago

Created
August 04, 2010 16:58
Category
License
All Rights Reserved (What is this?)
Additional Files


Viewed
3075 times

More from Dynamic Walking 2010

Dynamic Walking 2010. Anton Shiriaev. VHC Tools for Gait Analysis and Control.

Dynamic Walking 2010. Anton Shiriae...

Added 4 years ago | 00:34:00 | 3832 views

Dynamic Walking 2010. Stefano Stramigioli. Port-Based Robotics and Variable Impedance Actuators

Dynamic Walking 2010. Stefano Stram...

Added 4 years ago | 00:28:58 | 3398 views

Dynamic Walking 2010. Madhusudhan Venkadesan. Role of endurance running in human evolution, and how we ran without cushioned shoes

Dynamic Walking 2010. Madhusudhan V...

Added 4 years ago | 00:35:29 | 4289 views

Dynamic Walking 2010. Tom Roberts. Fast, cheap and out of control: dynamic interactions of elastic structures and muscle motors

Dynamic Walking 2010. Tom Roberts. ...

Added 4 years ago | 00:44:10 | 2697 views

Dynamic Walking 2010. Rodger Kram. Passive Elastic Running Prostheses; Very Good, But Not Yet Better.

Dynamic Walking 2010. Rodger Kram. ...

Added 4 years ago | 00:37:55 | 2590 views

Dynamic Walking 2010. Waleed Farahat. Optimal Workloop Energetics of Muscle-Actuated Systems: An Impedance Matching View

Dynamic Walking 2010. Waleed Faraha...

Added 4 years ago | 00:41:49 | 2954 views