Measurement of lumbar multifidus muscle contraction with rehabilitative ultrasound imaging

Kiesel, Kyle B.; Uhl, Tim L.; Underwood, Frank B.; Rodd, Donald W.; Nitz, Arthur J.

doi:10.1016/j.math.2006.06.011

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Volume 12, Issue 2 , Pages 161-166, May 2007

Measurement of lumbar multifidus muscle contraction with rehabilitative ultrasound imaging

Kyle B. Kiesel
- Department of Rehabilitation Sciences, Rehabilitation Sciences Doctoral Program, University of Kentucky College of Health Sciences, 900 South Limestone, CHS 126, Lexington, KY 40536-0200, USA
- Corresponding author. Department of Physical Therapy, University of Evansville, Evansville, IN 47714. Tel.: +8124792646; fax: +8124792717.
Tim L. Uhl
- Department of Rehabilitation Sciences, Division of Athletic Training, University of Kentucky, USA
Frank B. Underwood
- Department of Physical Therapy, University of Evansville, USA
Donald W. Rodd
- Department of Human Kinetics and Sport Studies, University of Evansville, USA
Arthur J. Nitz
- Department of Rehabilitation Sciences, Rehabilitation Sciences Doctoral Program, University of Kentucky College of Health Sciences, 900 South Limestone, CHS 126, Lexington, KY 40536-0200, USA
- Department of Rehabilitation Sciences, Division of Physical Therapy, University of Kentucky, USA

Received 7 March 2005; received in revised form 14 February 2006; accepted 2 June 2006.

Abstract

Rehabilitative Ultrasound Imaging (RUSI) has been validated as a noninvasive method to measure activation of selected muscles. The purpose of this study was to determine the relationship between muscle thickness change, as measured by ultrasonography, and electromyography (EMG) activity of the lumbar multifidus (LM) muscle in normal subjects.

Bipolar fine wire electrodes were inserted into the LM at the L4 level of five subjects. Simultaneous EMG and RUSI data (muscle thickness) were collected while subjects performed increasingly demanding postural response tasks thought to activate the LM muscle. To determine the relationship between muscle thickness change and EMG activity, the normalized EMG data were correlated to normalized RUSI data. To determine if the tasks increased the demand on the LM, the mean EMG data were compared over each of the four tasks.

Muscle thickness change as measured by RUSI was highly correlated with EMG activity of LM in asymptomatic subjects ( ).

Mean EMG data showed increasing levels of activation across tasks (19–34% of maximum voluntary isometric contraction (MVIC)). The results of the repeated measures ANOVA demonstrated theses differences were significant ( ).

Measurement of muscle thickness change utilizing RUSI is a valid and potentially useful method to measure activation of the LM muscle in a narrow range (19–34% of MVIC) in an asymptomatic population.

Keywords: Rehabilitation, Electromyography, Ultrasonography