Journal of Applied Physiology AJP: Heart and Circulatory Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 92: 1004-1012, 2002. First published November 2, 2001; doi:10.1152/japplphysiol.00954.2001
8750-7587/02 $5.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow All Versions of this Article:
92/3/1004    most recent
00954.2001v1
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (43)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tracy, B. L.
Right arrow Articles by Enoka, R. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tracy, B. L.
Right arrow Articles by Enoka, R. M.
Vol. 92, Issue 3, 1004-1012, March 2002

Older adults are less steady during submaximal isometric contractions with the knee extensor muscles

Brian L. Tracy and Roger M. Enoka

Department of Kinesiology and Applied Physiology, University of Colorado, Boulder, Colorado 80309-0354

This study compared the steadiness of submaximal contractions with the knee extensor muscles in young and old adults. Twenty young and twenty old subjects underwent assessment of isometric maximum voluntary contraction (MVC), one-repetition maximum (1-RM) strength, and steadiness during isometric, concentric, and eccentric contractions with the knee extensor muscles. The old adults displayed 33% lower MVC force and a 41% lower 1-RM load. The coefficient of variation for force was significantly greater for the old adults during isometric contractions at 2, 5, and 10% of MVC but not at 50% MVC. The decline in steadiness at low forces experienced by the men was marginally greater than that experienced by the women. The steadiness of concentric and eccentric contractions was similar in young and old adults at 5, 10, and 50% of 1-RM load. Old subjects exhibited greater coactivation of an antagonist muscle compared with young subjects during the submaximal isometric and anisometric contractions. These results indicate that, whereas the ability to exert steady submaximal forces with the knee extensor muscles was reduced in old adults, fluctuations in knee joint angle during slow movements were similar for young and old adults.

aging; steadiness; motor control; muscle strength


This article has been cited by other articles:


Home page
 JBJSHome page
A. L. Bryant, Y.-H. Pua, and R. A. Clark
Morphology of Knee Extension Torque-Time Curves Following Anterior Cruciate Ligament Injury and Reconstruction
J. Bone Joint Surg. Am., June 1, 2009; 91(6): 1424 - 1431.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
C. T. Moritz, B. K. Barry, M. A. Pascoe, and R. M. Enoka
Discharge Rate Variability Influences the Variation in Force Fluctuations Across the Working Range of a Hand Muscle
J Neurophysiol, May 1, 2005; 93(5): 2449 - 2459.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
M. Kouzaki, M. Shinohara, K. Masani, and T. Fukunaga
Force fluctuations are modulated by alternate muscle activity of knee extensor synergists during low-level sustained contraction
J Appl Physiol, December 1, 2004; 97(6): 2121 - 2131.
[Abstract] [Full Text] [PDF]

Home page
 Journals of Gerontology Series A: Biological Sciences and Medical SciencesHome page
B. K. Barry and R. G. Carson
The Consequences of Resistance Training for Movement Control in Older Adults
J. Gerontol. A Biol. Sci. Med. Sci., July 1, 2004; 59(7): M730 - M754.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
B. L. Tracy, W. C. Byrnes, and R. M. Enoka
Strength training reduces force fluctuations during anisometric contractions of the quadriceps femoris muscles in old adults
J Appl Physiol, April 1, 2004; 96(4): 1530 - 1540.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
M. Shinohara, Y. Yoshitake, M. Kouzaki, H. Fukuoka, and T. Fukunaga
Strength training counteracts motor performance losses during bed rest
J Appl Physiol, October 1, 2003; 95(4): 1485 - 1492.
[Abstract] [Full Text] [PDF]

Home page
 Journals of Gerontology Series A: Biological Sciences and Medical SciencesHome page
E. A. Christou, Y. Yang, and K. S. Rosengren
Rapid Communication. Taiji Training Improves Knee Extensor Strength and Force Control in Older Adults
J. Gerontol. A Biol. Sci. Med. Sci., August 1, 2003; 58(8): M763 - 766.
[Abstract] [Full Text] [PDF]

Home page
 Journals of Gerontology Series A: Biological Sciences and Medical SciencesHome page
P. C. LaStayo, G. A. Ewy, D. D. Pierotti, R. K. Johns, and S. Lindstedt
The Positive Effects of Negative Work: Increased Muscle Strength and Decreased Fall Risk in a Frail Elderly Population
J. Gerontol. A Biol. Sci. Med. Sci., May 1, 2003; 58(5): M419 - 424.
[Abstract] [Full Text] [PDF]

Home page
 Journals of Gerontology Series A: Biological Sciences and Medical SciencesHome page
T. Hortobagyi, C. Mizelle, S. Beam, and P. DeVita
Old Adults Perform Activities of Daily Living Near Their Maximal Capabilities
J. Gerontol. A Biol. Sci. Med. Sci., May 1, 2003; 58(5): M453 - 460.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
D. E. Vaillancourt and K. M. Newell
Aging and the time and frequency structure of force output variability
J Appl Physiol, March 1, 2003; 94(3): 903 - 912.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online