| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Research Reports |
JK-F Ng, MPhtySt, is Assistant Professor, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. He was a postgraduate student in the Department of Physiotherapy, The University of Queensland, at the time this study was completed.
CA Richardson, PhD, is Senior Lecturer, Department of Physiotherapy, The University of Queensland, Brisbane, Queensland, Australia 4072 (richardson@physio.therapies.uq.edu.au).
GA Jull, MPhty, FACP, is Reader, Department of Physiotherapy, The University of Queensland.
Background and Purpose. Muscle endurance is an important variable to measure in the assessment of back muscle function. This study investigated the electromyographic (EMG) activity and fatigue patterns of iliocostalis lumborum and multifidus muscles during a trunk holding test. Subjects. Sixteen male subjects (mean age=24.2 years, SD=4.2, range=20.6–31.9) without low back pain or known pathology were recruited in the study. Methods. Surface EMG electrodes were used to record the activity of iliocostalis lumborum and mutifidus muscles during a 60-second isometric contraction. To reflect the activity level and fatigue rate of the muscles, EMG amplitude (root mean square [RMS] values) and a frequency variable (median frequency [MF]) were measured. Results. The multifidus muscle displayed a higher level of activity, initial MF, and normalized MF slope than did the iliocostalis lumborum muscle. There was no difference, however, in the normalized RMS slope between the two muscles. The correlations between the normalized MF slope and the RMS slope of the two muscles were nonsignificant. Conclusion and Discussion. This study shows that monitoring frequency changes of the EMG signals may enable therapists to quantify the fatigue changes of individual muscles during the trunk holding test. The higher fatigue rate shown in the multifidus muscle compared with the iliocostalis lumborum muscle may be due to the higher activity level of the multifidus muscle during the trunk holding contraction. This greater activity of the multifidus muscle during the contraction might be explained by the functional differences between these two muscles.
Key Words: Back • Electromyography • Fourier analysis • Isometric contraction • Muscle fatigue
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  P. J. Mork and R. H. Westgaard Long-term electromyographic activity in upper trapezius and low back muscles of women with moderate physical activity J Appl Physiol, August 1, 2005; 99(2): 570 - 578. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. H. Silber, A. J. Goldman, J. K.- F. Ng, C. A. Richardson, G. A. Jull, H. Lahrmann, U. Zifko, W. Grisold, S. L. Pullman, D. Goodin, et al. Clinical utility of surface EMG: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology Neurology, May 22, 2001; 56(10): 1421 - 1422. [Full Text] [PDF]
|
|
|
|
|
|
S. L. Pullman, D. S. Goodin, A. I. Marquinez, S. Tabbal, and M. Rubin Clinical utility of surface EMG: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology Neurology, July 25, 2000; 55(2): 171 - 177. [Full Text] [PDF]
|
|
|
|
 |
|
 G. L Soderberg and L. M Knutson A Guide for Use and Interpretation of Kinesiologic Electromyographic Data Physical Therapy, May 1, 2000; 80(5): 485 - 498. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
