Evidence synthesis showed limited evidence supporting poor baseline transversus abdominis contraction thickness ratio as a treatment effect modifier favoring motor control exercise .
Limited evidence supported that high baseline transversus abdominis lateral slide was associated with higher pain intensity after various exercise interventions at 1-year follow-up .
However , there was limited evidence for the absence of relation between the contraction thickness ratio of transversus abdominis or anticipatory onset of lateral abdominal muscles at baseline and the short- or long-term LBP intensity after exercise interventions .
There was conflicting evidence for a relation between baseline percent thickness change of lumbar multifidus during contraction and the clinical outcomes of patients after various conservative treatments .
Although individual reports suggest that baseline morphometry or activity of transversus abdominis or lumbar multifidus predict clinical outcome of low back pain ( LBP ) , a related systematic review is unavailable .
Therefore , this review summarized evidence regarding the predictive value of these muscular characteristics .
Association between changes in electromyographic signal amplitude and abdominal muscle thickness in individuals with and without lumbopelvic pain.
STUDY DESIGN Validation study . OBJECTIVES To investigate the association between changes in electromyographic ( EMG ) signal amplitude and sonographic measures of muscle thickness of 4 abdominal muscles , during 2 clinical tests , in adults with and without lumbopelvic pain . BACKGROUND There is a trend in rehabilitation to use ultrasound imaging ( USI ) to determine the extent of abdominal muscle contraction . However , the literature investigating the relationship between abdominal muscle thickness change and level of activation is inconclusive and has not included clinical ly relevant tasks . METHODS Simultaneous recording from fine-wire EMG and USI was performed for 4 abdominal muscles , in 7 adults with lumbopelvic pain ( mean ± SD age , 29.7 ± 12.0 years ) and 7 adults without lumbopelvic pain ( 32.0 ± 10.6 years ) , during an active straight leg raise ( ASLR ) test and an abdominal drawing-in maneuver  ( ADIM ) . Cross-correlation functions and linear regression analyses were used to describe the relationship between the 2 measures . Analyses of variance were used to compare individuals with and without lumbopelvic pain , with an alpha set at .05 . RESULTS Across all muscles , peak cross-correlation values were low ( ASLR , r = 0.28 ± 0.09 ; ADIM , r = 0.35 ± 0.11 ) , and there was large variability in associated time lags ( ASLR , τ = 0.69 ± 2.56 seconds ; ADIM , τ = 0.53 ± 3.75 seconds ) . Regression analyses did not detect a systematic pattern of association between EMG signal amplitude and USI measurements , and analyses of variance revealed no differences between cohorts . CONCLUSION These results suggest a weak relationship between EMG amplitude and abdominal muscle thickness change measured with USI during the ADIM and ASLR , and raise questions about thickness change derived from USI as a measure of muscular activity for the abdominal musculature
Evidence synthesis showed limited evidence supporting poor baseline transversus abdominis contraction thickness ratio as a treatment effect modifier favoring motor control exercise .
Limited evidence supported that high baseline transversus abdominis lateral slide was associated with higher pain intensity after various exercise interventions at 1-year follow-up .
However , there was limited evidence for the absence of relation between the contraction thickness ratio of transversus abdominis or anticipatory onset of lateral abdominal muscles at baseline and the short- or long-term LBP intensity after exercise interventions .
There was conflicting evidence for a relation between baseline percent thickness change of lumbar multifidus during contraction and the clinical outcomes of patients after various conservative treatments .
Although individual reports suggest that baseline morphometry or activity of transversus abdominis or lumbar multifidus predict clinical outcome of low back pain ( LBP ) , a related systematic review is unavailable .
Therefore , this review summarized evidence regarding the predictive value of these muscular characteristics .