Onset in abdominal muscles recorded simultaneously by ultrasound imaging and intramuscular electromyography

Location and sequence of muscle onset in deep abdominal muscles measured by different modes of ultrasound imaging

“…Muscle deformation onset determined by US imaging has shown results in agreement with muscle activity onset determined by intramuscular EMG (McMeeken et al, 2004;Vasseljen et al, 2009). Both US m-mode Vasseljen et al, 2006) and US SR (Vasseljen et al, 2009) are shown to be valid and reliable for detecting the first muscle onset in deep abdominal muscles, while subsequent onsets from different muscles or depth layers can reliably be detected by US SR only.…”

“…Both US m-mode Vasseljen et al, 2006) and US SR (Vasseljen et al, 2009) are shown to be valid and reliable for detecting the first muscle onset in deep abdominal muscles, while subsequent onsets from different muscles or depth layers can reliably be detected by US SR only. However, the US SR method is technically challenging causing considerable problems with missing data and interpretation difficulties due to muscle movement occurring transversally to the US beam axis (Marwick, 2006;Vasseljen et al, 2009). These are minor problems with US mmode .…”

“…Motion-mode (US m-mode ) imaging is based on recordings of directional tissue displacements towards and away from the transducer over time, and can thereby detect the temporal starting point of muscle activity (onset). However, US m-mode cannot accurately determine the site of onset nor subsequent onsets in other muscles along the scan line once the initial onset is triggered Vasseljen et al, 2009). To solve this, tissue velocity imaging (TVI), which quantifies both the direction and the velocity of tissue displacement has been introduced (Grubb et al, 1995;Heimdal et al, 1998;Peolsson et al, 2008).…”

Spine stabilisation exercises in the treatment of chronic low back pain: a good clinical outcome is not associated with improved abdominal muscle function

“…Whilst ultrasound recordings have been shown to be reliable and valid for assessing the ''earliest onset of activity'' within deeplying the lateral abdominal muscle group [37,62,67] they cannot be used to identify with any certainty which of the lateral abdominal muscles (TrA, OI or OE) is activated first. Possible reasons for this have been discussed in detail before [37,60,62,67]. Nonetheless, the latter authors maintain that the ''earliest muscle active'' gives an adequate measure for clinical studies in this area, delivering a valid representation of the phenomenon under investigation.…”

“…Nonetheless, the latter authors maintain that the ''earliest muscle active'' gives an adequate measure for clinical studies in this area, delivering a valid representation of the phenomenon under investigation. Indeed, due to the wide intraindividual and interindividual variabilities in the onset responses of the three muscles, some authors consider that examination of the ''earliest onset of activity'' may even convey certain advantages, by taking account of individual activation strategies that can otherwise be obscured by averaging group data for any given muscle [37,62,67]. This, coupled with the obvious benefit of using a non-invasive procedure in the assessment of patients, appears to make it a feasible approach for studies of deep muscle activation in connection with cLBP.…”