We found conflicting data regarding the validity of methods used to examine back muscle fatigue .
The Biering-Sorensen test  , performed in conjunction with surface electromyography spectral analysis , turned out to be the most widely used and comparatively , the most optimal modality currently available to assess objective back muscle fatigue in daily clinical practise , even though critical limitations are discussed .
Implication s for Rehabilitation Despite its limitations , the Biering-Sorensen test is currently the most used , convenient and easily available fatiguing test for lumbar muscles .
Pooled mean frequency and half-width of the spectrum are currently the most valid electromyographic parameters to assess fatigue in chronic non-specific low back pain .
PURPOSE This systematic literature review aim ed at examining the validity and applicability in everyday clinical rehabilitation practise of methods for the assessment of back muscle fatiguability in patients with chronic non-specific low back pain ( CNSLBP ) .
Chronic low back pain measurement with visual analogue scales in different settings
& NA ; We asked 78 chronic low back pain patients to report on their usual pain intensity , and on the lifestyle changes caused by their pain , on a horizontally‐oriented visual analogue scale ( VAS ) . Also , the usual and the current pain  intensities were examined on a vertical VAS . Statistical analysis showed normal distribution of data in the measurement of usual pain on the horizontal VAS , but no homogeneous distribution on the vertical VAS . Therefore , in the measurement of chronic low back pain VAS should be used horizontally rather than vertically , because of higher sensitivity . The intensity of usual pain was significantly correlated with the degree of lifestyle change . No correlation was found between current and usual pain . There was no significant difference in the failure rate between the vertical and horizontal VAS . Also , there was no reduction of the failure rate by giving additional oral explanations in the use of the scale to the patient . Owing to a negative influence in distribution of rates and an increase in the failure rate , complex questions should be avoided . A short written introduction to the scale is sufficient , and oral explanations are not essential
We found conflicting data regarding the validity of methods used to examine back muscle fatigue .
The Biering-Sorensen test  , performed in conjunction with surface electromyography spectral analysis , turned out to be the most widely used and comparatively , the most optimal modality currently available to assess objective back muscle fatigue in daily clinical practise , even though critical limitations are discussed .
Implication s for Rehabilitation Despite its limitations , the Biering-Sorensen test is currently the most used , convenient and easily available fatiguing test for lumbar muscles .
Pooled mean frequency and half-width of the spectrum are currently the most valid electromyographic parameters to assess fatigue in chronic non-specific low back pain .
PURPOSE This systematic literature review aim ed at examining the validity and applicability in everyday clinical rehabilitation practise of methods for the assessment of back muscle fatiguability in patients with chronic non-specific low back pain ( CNSLBP ) .