Subject: ScienceDirect - Journal of Biomechanics : Optimal muscular coordination strategies for jumping



   

 

Login:   

Register

 

 

Home

Browse

My Settings

Alerts

Help


 Quick Search

  Title, abstract, keywords


  Author




  

  Journal/book title


  Volume


  Issue


  Page


         


Journal of Biomechanics

Volume 24, Issue 1, 1991, Pages 1-10

Result list |  previous  < 52 of 56 >  next 

Font Size:     


  Abstract

- selected

 

 

References

 

 

  Purchase PDF (1179 K)

 


   E-mail Article   

   Add to my Quick Links   

 

 

   Cited By in Scopus (69)

 

 

Related Articles in ScienceDirect

 

An optimal control model for maximum-height human jumpi...

Journal of Biomechanics

 

The influence of the biarticularity of the gastrocnemiu...

Journal of Biomechanics

 

On the role of biarticular muscles in human jumping

Journal of Biomechanics


 

View More Related Articles

 

 

View Record in Scopus

 doi:10.1016/0021-9290(91)90321-D      

Copyright © 1991 Published by Elsevier Science Ltd.

Optimal muscular coordination strategies for jumping 

Marcus G. Pandy and Felix E. Zajac

Design Division, Mechanical Engineering Department, Stanford University, Stanford, CA 94305-4021, U.S.A.

Rehabilitation Research and Development Center (153), Veterans' Administration Medical Center, Palo Alto, CA 94304-1200, U.S.A.


Received 28 February 1990.  Available online 9 April 2004. 

 

Abstract

This paper presents a detailed analysis of an optimal control solution to a maximum height squat jump, based upon how muscles accelerate and contribute power to the body segments during the ground contact phase of  jumping.  Quantitative comparisons of model and experimental results expose a proximal-to-distal sequence of muscle activation (i.e. from hip to  knee  to ankle). We found that the contribution of muscles dominates both the angular acceleration and the instantaneous power of the segments. However, the contributions of gravity and segmental motion are insignificant, except the latter become important during the final 10% of the jump. Vasti and gluteus maximus muscles are the major energy producers of the lower extremity. These muscles are the prime movers of the lower extremity because they dominate the angular acceleration of the hip toward extension and the instantaneous power of the trunk. In contrast, the ankle plantarflexors (soleus, gastrocnemius, and the other plantarflexors) dominate the total energy of the thigh, though these muscles also contribute appreciably to trunk power during the final 20% of the jump. Therefore, the contribution of these muscles to overall  jumping  performance cannot be neglected. We found that the biarticular gastrocnemius increases jump height (i.e. the net vertical displacement of the center of mass of the body from standing) by as much as 25%. However, this increase is not due to any unique biarticular action (e.g. proximal-to-distal power transfer from the  knee  to the ankle), since  jumping  performance is similar when gastrocnemius is replaced with a uniarticular ankle plantarflexor.

Article Outline

• References


Journal of Biomechanics

Volume 24, Issue 1, 1991, Pages 1-10

Result list | previous < 52 of 56 > next 

 

 

Home

Browse

My Settings

Alerts

Help

 

About ScienceDirect  |  Contact Us  |  Terms & Conditions  |  Privacy Policy

 

Copyright © 2008 Elsevier B.V. All rights reserved. ScienceDirect® is a registered trademark of Elsevier B.V.