Document Type
Article
Publication Date
5-15-2018
Abstract
Background
Low back pain (LBP) is commonly associated with paraspinal muscle dysfunctions. A method to study deep lumbar paraspinal (i.e. multifidus) muscle function and neuromuscular activation pattern is intramuscular electromyography (EMG). Previous studies have shown that the procedure does not significantly impact muscle function during activities involving low-level muscle contractions. However, it is currently unknown how muscular function and activation are affected during high-exertion contractions.
Objective
To examine the effects of insertion and presence of fine-wire EMG electrodes in the lumbar multifidus on muscle strength, endurance, and activation profiles during high-exertion spinal extension muscle contractions.
Design
Single-blinded, repeated measures intervention trial.
Setting
University clinical research laboratory
Participants
Twenty individuals between the ages of 18-40 free of recent and current back pain.
Methods
Muscle performance was assessed during 3 conditions (with [WI] and without [WO] presence of intramuscular electrodes, and insertion followed by removal [IO]). Isometric spinal extension strength was assessed with a motorized dynamometer. Muscle endurance was assessed using the Sorensen test with neuromuscular activation profiles analyzed during the endurance test.
Main Outcome Measurements
Spinal extensor muscle strength, endurance, and activation.
Results
Our data showed no significant difference in isometric strength (p=.20) between the 3 conditions. A significant difference in muscle endurance was found (p=.03). Post-hoc analysis showed that the muscle endurance in the IO condition was significantly higher than the WO condition (161.3±58.3 vs. 142.1±48.2 sec, p=.04), likely due to a learning effect. All 3 conditions elicited minimal pain (range 0-4/10) and comparable muscle activation profiles.
Conclusion
Our findings suggested the sonographically guided insertion and presence of fine-wire intramuscular EMG electrodes in the lumbar multifidus muscles had no significant impact on spinal extension muscle function. This study provides evidence that implementing intramuscular EMG does not affect muscle performance during high-exertion contractions in individuals with no current back pain.
Level of Evidence
II
Recommended Citation
Lee S-P, Smith JA, Kimber M, Houk K. Insertion and presence of finewire intramuscular electrodes to the lumbar paraspinal muscles do not affect muscle performance and activation during high-exertion spinal extension activities. PM&R. 2018. doi: 10.1016/j.pmrj.2018.05.006
Peer Reviewed
1
Copyright
American Academy of Physical Medicine and Rehabilitation
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Comments
NOTICE: this is the author’s version of a work that was accepted for publication in PM&R. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in PM&R in 2018. DOI:10.1016/j.pmrj.2018.05.006
The Creative Commons license below applies only to this version of the article.