SciELO - Scientific Electronic Library Online

vol.16 issue5Gait characteristics of younger-old and older-old adults walking overground and on a compliant surfaceMusculoskeletal pain, profile and quality of life of individuals with sickle cell disease author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand



Related links

  • On index processCited by Google
  • Have no similar articlesSimilars in SciELO
  • On index processSimilars in Google


Brazilian Journal of Physical Therapy

Print version ISSN 1413-3555


LIMA, Pedro O. P. et al. Concurrent validity of the pressure biofeedback unit and surface electromyography in measuring transversus abdominis muscle activity in patients with chronic nonspecific low back pain. Rev. bras. fisioter. [online]. 2012, vol.16, n.5, pp.389-395.  Epub July 24, 2012. ISSN 1413-3555.

BACKGROUND: The Pressure biofeedback unit (PBU) is an assessment tool used in clinical practice and research aimed to indirectly analyze the transversus abdominis (TrA) muscle activity. The concurrent validity of the PBU in a clinically relevant sample is still unclear. OBJECTIVE: The purpose of this study was to evaluate the concurrent validity and diagnostic accuracy of the PBU in measuring TrA muscle activity in patients with chronic nonspecific low back pain. METHOD: This study was performed using a validation, cross-sectional design. Fifty patients with chronic nonspecific low back pain were recruited for this study. To test the concurrent validity both PBU measures (index test) and superficial electromyographic measures (reference-standard test) were compared and collected by a physical therapist in a series of voluntary contraction maneuvers of TrA muscle. RESULTS: Participants were on average 22 years old, weighed 63.7 kilos, 1.70 meters height and mean low back pain duration was 1.9 years. It was observed a weak and non-significant Phi coefficient (r=0.2, p<0.20). With regards to diagnostic accuracy tests, our results suggest a low sensitivity (60%) and specificity (60%) of the PBU. The positive predictive value was high (0.8) and negative predictive value was low (0.2). Conclusions: Concurrent validity of the PBU in measuring TrA muscle activity in patients with chronic nonspecific low back pain is poor given the low correlation and diagnostic accuracy with superficial EMG.

Keywords : pressure biofeedback unit; low back pain; physical therapy.

        · abstract in Portuguese     · text in English     · English ( pdf epdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License