Kinematic study of human ankle control during walking

In order to determine the extent to which ankle motion is voluntarily controlled during walking, angular velocity measurements at the ankle were taken in two cases. In the first case, subjects were seated and instructed to move their ankle as quickly as possible in eight directions indicated by a computer program in dorsi- and plantar-flexion and inversion and eversion. In the second case, subjects were instructed to walk on a treadmill for thirty seconds at a normal pace, and at speeds that felt faster and slower than normal. Velocity measurements were made using an exoskeletal robot, called the Anklebot, originally designed for rehabilitation purposes. The electromyogram of anterior tibialis, peroneus longus, and gastrocnemius muscles was also recorded. Results showed that all subjects plantarflexed their foot at a higher velocity after heel-strike while walking than when moving at their maximum voluntary speed. This implies that this motion results in part from foot-ground interaction mediated by the mechanical impedance of the ankle and is not solely imposed by contraction of the gastrocnemius and other muscles. In contrast, results also showed that subjects were able to dorsiflex their foot at a higher velocity when moving at maximum voluntary speed than was observed after toe-off while walking.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2009

Author dc:creator

• Zimmerman, Julia C

Advisor dc:contributor.advisor

• Neville Hogan.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/54546

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/54546