Electromyographic power spectral analysis of the paraspinal muscles: Reliability study

Abstract

Background and Purpose Despite previous studies on the reliability of median frequency (MF) and median frequency slope (MFS) as specific surface electromyography (SEMG) measures of back muscle function, there is still no general consensus regarding the results. A reliability study was carried out to determine the test-retest reliability (within and between-days) of SEMG power spectral analysis of paraspinal muscle activity in healthy subjects. Methods Fifteen volunteer subjects with no history of low back pain were tested. The unsupported trunk holding position was used to measure initial MF and MFS three times. Two measurements were taken on the same day with five minutes interval and the third was taken one week later. Results For initial MF, the high ICC values (0.82-0.92) and high level of agreement between measurements for multifidus and iliocostalis indicated high within and between-days reliability. For MFS, the ICC values (0.65-0.82) and high (for multifidus) to moderate (for iliocostalis) level of agreement between measurements demonstrated high within-day reliability for multifidus and moderate for iliocostalis. Between-days reliability of MFS was found to be good for multifidus and moderately good for iliocostalis with ICC values of 0.60-0.85 and high to moderate level of agreement. Conclusion In this study the SEMG power spectral analysis was shown to be a reliable method of measuring back muscle activity in an unsupported trunk holding test, when measurements are taken in healthy subjects by the same investigator.

Publication Title

Physiotherapy

Link to Full Text

Share

COinS