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 ) .
Specificity of a back muscle exercise machine in healthy and low back pain subjects.
PURPOSE To determine whether dynamic back muscle endurance exercises in a semisitting position induce more fatigue in back muscles than that in hip extensors in healthy controls as well as in patients with nonspecific chronic low back pain . METHODS Sixteen healthy volunteers and 18 volunteers with nonspecific chronic low back pain performed trunk flexion-extension cycles until exhaustion at 60 % of their strength in a machine design ed for back exercise in a semisitting position with knees ' angle at 135 degrees . The number of cycles and perceived muscle fatigue ( Borg CR-10 scale ) at five areas ( upper and lower back , gluteus , hamstrings , and quadriceps ) were used as fatigue criteria . EMG signals were recorded bilaterally on four back muscles , two hip extensors ( gluteus maximus and biceps femoris ) , and the vastus medialis . The slope values of the instantaneous median frequency values computed over time were retained as EMG indices of fatigue . RESULTS The number of cycles was equivalent in healthy controls ( n = 23 + /- 13 ) and patients with back pain ( n = 27 + /- 16 ) . EMG indices of fatigue disclosed evidence of muscle fatigue in all the back muscles and the vastus medialis , contrary to hip extensors . EMG revealed significantly more muscle fatigue of lower back muscles , which was further corroborated by the Borg scale assessment . No between-group difference was obtained in any EMG comparison . CONCLUSION These results showed that this type of exercise machine can specifically train the back muscles , and this as much in subjects with nonspecific chronic low back pain as in healthy controls . This has implication s for the training of back muscle endurance , especially in patients with back pain for whom poor back muscle endurance is sometimes of concern
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 ) .