Neuroscience 2003 Abstract
| Presentation Number: | 392.8 |
|---|---|
| Abstract Title: | Correlation of magnetic resonance imaging T2 times with electromyographic activity. |
| Authors: |
Segal, R. L.*1,2,3
; Poeppelman, A.1
; Ward, M.2
; Giordano, S. B.1
1Program in Neurosci., Emory Univ, Atlanta, GA 2GA, Room 213 Ctr. for Rehab Med, 30322, 3USA, Room 213 Ctr. for Rehab Med, 30322, |
| Primary Theme and Topics |
Motor Systems - Muscle and Motor Unit -- Physiology |
| Secondary Theme and Topics | Motor Systems<br />- Muscle and Motor Unit<br />-- Anatomy |
| Session: |
392. Muscle & Motor Unit: Function Poster |
| Presentation Time: | Monday, November 10, 2003 11:00 AM-12:00 PM |
| Location: | Morial Convention Center - Hall F-I, Board # I28 |
| Keywords: | Muscle, Motor Unit, Leg Muscles, MRI |
Global delineation of the spatial distribution of muscle activity is difficult because of the sampling constraints inherent in electromyographic (EMG) activity recordings. A relatively new approach to study this global activity involves the use of dynamic magnetic resonance (MR) images (T2 weighted) pre and post exercise. Because the “gold standard” for measuring muscle activity in humans is monitoring EMG activity, T2 times need to be shown to correlate with EMG activity and behavioral measures (e.g. amount of effort) of activity. Able-bodied subjects carried out concentric ankle plantarflexion contractions against loads equal to 25% and 65% of maximal voluntary contraction (MVC) while EMG activity was recorded from surface electrodes overlying the skin over the lateral gastrocnemius (LG), medial gastrocnemius (MG), peroneal (PER), soleus (SOL) and tibialis anterior (TA) muscles. All subjects had pre and post exercise T2 time measurements and pre-exercise T1 sequences of the right leg while secured in an axial multi-element volumetric coil. Plantarflexor EMG activity and T2 time correlated well at the higher level of effort except for MG (Average r2=.757; LG=.784; MG=.589; PER=.903; SOL=.751). Correlations at the lower level of effort were not as high (Average r2=.508;LG=.487; MG=.636; PER=.441; SOL=.466). The smaller correlations at the lower level of activity may be due to a threshold effect that has been previously reported for other muscles (Chang et al., 1995).
Supported by NICHD NCMRR grant HD 32571
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
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