Do Changes in Transversus Abdominis and Lumbar Multifidus During Conservative Treatment Explain Changes in Clinical Outcomes Related to Nonspecific Low Back Pain?

Research conducted previously describes an inconsistent relationship between temporal changes in transversus abdominis or lumbar multifidus and temporal changes in clinical outcomes. Unfortunately, a relevant systematic review is not available. Therefore, this systematic review was designed to summarize evidence dealing with the association between temporal changes in muscle morphometry and activity in response to treatment, and temporal changes in clinical outcomes. Candidate publications were identified from 6 electronic databases. Fifteen articles were included after examination by 2 reviewers using predetermined selection criteria. The methodological quality of these articles was appraised using a standard tool. These methods showed strong evidence that temporal alterations in transversus abdominis thickness change during contraction (as measured by B-mode or M-mode ultrasound) or feedforward activation of transversus abdominis (assessed via electromyography, tissue Doppler imaging, or M-mode ultrasound) were not related to temporal changes in low back pain (LBP)/LBP-related disability. There was limited evidence that temporal changes in transversus abdominis lateral sliding or lumbar multifidus endurance weren’t related to temporal changes in LBP intensity. Conflicting evidence was seen for the relation between temporal changes in lumbar multifidus morphometry and temporal changes in LBP/LBP-related disability. This review highlights that temporal changes in transversus abdominis features tend to be unrelated to the corresponding LBP/LBP-related disability improvements, whereas the relation between multifidus changes and clinical improvements remains uncertain.

This systematic review highlighted that changes in morphometry or activation of transversus abdominis following conservative treatments are usually not associated with the corresponding changes in clinical outcomes. The relation between posttreatment changes in characteristics of lumbar multifidus and clinical improvements is still not certain.