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 ) .
The use of surface EMG power spectral analysis in the evaluation of back muscle function.
The rate of decline in the median frequency ( MF ) of the surface EMG power spectrum ( MFgrad ) has been evaluated for its use in monitoring the fatigability of the erector spinae muscles during the performance of submaximal isometric contractions . MFgrad consistently displayed a highly significant relationship with endurance time for the task ( p < 0.05 ) , giving a slightly better correlation for contractions performed in lordotic postures , with the back muscles in a shortened position , than in flexed postures . No significant difference existed between mean MFgrad values recorded from the right and left erector spinae muscles , at either thoracic or lumbar levels . The back extensor muscles of men were more fatigable than those of women , and this has been discussed in relation to corresponding differences in muscle fiber type relative size . Greater erector spinae muscle fatigability was associated with both the existence of , and the risk of developing , serious low back pain .  Possible mechanisms for the association , from retrospective and prospect i ve points of view , have been advanced
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 ) .