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 .
Publication bias in clinical research
In a retrospective survey , 487 research projects approved by the Central Oxford Research Ethics Committee between 1984 and 1987 , were studied for evidence of publication bias . As of May , 1990 , 285 of the studies had been analysed by the investigators , and 52 % of these had been published . Studies with statistically significant results were more likely to be published than those finding no difference between the study groups ( adjusted odds ratio [ OR ] 2.32 ; 95 % confidence interval [ Cl ] 1.25 - 4.28 ) . Studies with significant results were also more likely to lead to a greater number of publications and presentations and to be published in journals with a high citation impact factor . An increased likelihood of publication was also associated with a high rating by the investigator of the importance of the study results , and with increasing sample size . The tendency towards publication bias was greater with observational and laboratory-based experimental studies ( OR = 3.79 ; 95 % Cl = 1.47 - 9.76 ) than with r and omised clinical trials ( OR = 0.84 ; 95 % Cl = 0.34 - 2.09 ) . We have confirmed the presence of publication bias in a cohort of clinical research studies . These findings suggest that conclusions based only on a review of published data should be interpreted cautiously , especially for observational studies . Improved strategies are needed to identify the results of unpublished as well as published studies
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 .