Author: Matthew Craig – bounceREHAB Physiotherapist & Director
Co-Author: Paul Dardagan – bounceREHAB Physiotherapist & Director
Real time ultrasound (RTUS) is an emerging imaging modality in physiotherapy. RTUS involves sending short pulses of ultrasound into the body and using reflections received from tissue interfaces to produce images of internal structures. Lower back pain (LBP) is a major health problem with a prevalence of about 23% resulting in 11-12% of the population being disabled by LBP (Balagué, Mannion et al. 2012). Anecdotal evidence suggests that RTUS is being used as an assessment and biofeedback tool by physiotherapists for various deep core stabilising muscles (Jedrzejczak and Chipchase 2008). This blog aims to assess the research available for the use of RTUS by physiotherapists in the assessment and management of LBP.
RTUS: current usage in Australian Physiotherapy
RTUS related to musculoskeletal rehabilitation has been ongoing since the 1980’s (Whittaker 2006), and investigation has established that it has a role as a safe, cost-effective (as opposed to the alternative of magnetic resonance imaging), and accessible method for visualising and measuring the deep muscles of the trunk (Stokes, Rankin et al. 2005).
RTUS appears to be a relatively uncommon modality used by physiotherapy across the board in Australia, potentially limited by insufficient access to equipment and educational opportunities. The surveyed findings by Jedrzejczak and Chipchase (2008) suggested that at the time of their research, only a small proportion of South Australian physiotherapists used RTUS (11.6%), while slightly more had access to a machine (19.4%). RTUS was used most commonly for assessment (88.3%) and biofeedback (87.0%) of the abdominal (94.7%), pelvic floor (72.7%) and multifidus (54.5%) muscles.
Assessment and biofeedback using RTUS for LBP
Research into muscle impairment in LBP has led to the realisation that there is a specific impairment in the deep muscles of the trunk, notably the transversus abdominis (TA), the segmental multifidus (MF) and pelvic floor (PF) (Hides et al. 1994, 1996; Hodges et al. 1996; Hodges and Richardson 1996, 1998). Randomised trials have evaluated the efficacy of specific rehabilitation that focuses on co-activation of these deep muscles (O’sullivan, Phyty et al. 1997). Evidence suggests that it is very important that these deep muscles are specifically targeted in rehabilitation, i.e. their action is assured independent of other trunk muscles (Hodges & Richardson 1997).
In the case of the MF, research has shown that the effect on the muscle following injury is rapid and very specific to the injured vertebral segment (Hides et al. 1994; Hides, Richardson et al. 1998). The approach to exercise therapy needs to be very precise as the unaffected parts of the MF and other muscles, such as the thoracic components of the erector spinae, will be more easily activated when rehabilitation is attempted (Stokes, Rankin et al. 2005).
In the case of the TA, it is apparent that if separate control of the muscle is lost, a generalised activation of more superficial abdominal muscles will ensue. The necessity for such care and precision with RTUS facilitation is both supported and evidence based (Ferreira, Ferreira et al. 2004).
So why use RTUS and what are the alternatives?
Palpation is the alternative biofeedback method to clinically assess motor control of TA and MF. There is the drawback that the muscles to be targeted are deep and therefore assessment strategies are by necessity will be somewhat indirect (Hides, Richardson et al. 1998). Alternatively, real-time ultrasound imaging is an advantageous modality as it allows immediate visualisation of contraction of the deep muscles such as the TA and the MF (McPherson and Watson 2014). Furthermore it is non-invasive, quick and could be useful for both assessment and facilitation of these muscles (Chipchase, Thoirs et al. 2009). Dietz, Wilson et al. (2001) showed that 32 of 56 women learned correct activation of their pelvic floor muscles with less than 5 minutes of RTUS biofeedback training.
Even from a conservative viewpoint, the value of RTUS from a LBP rehabilitative perspective is it allows for dynamic study of muscle groups as they contract. Consequently, the complementary use of RTUS enhances the clinical analysis of the musculature system and has been advocated by many authors (Richardson, Hodges et al. 2004; Kermode 2004; Whittaker 2004; Henry and Westervelt 2005). In addition, numerous studies (Bunce, Moore et al. 2002; Hodges, Pengel et al. 2003; Stokes, Rankin et al. 2005) show that RTUS withstands scientific rigor when applied clinically and that it is both a valid and reliable method to ascertain muscle size (through static quantitative measurements of muscle width, length, depth, cross-sectional area, or volume) and hence can be used as an indicator of muscle activity.
Why is it important to have a skilled physiotherapist in the use of RTUS?
While RTUS is an attractive modality for physiotherapists, simply visualizing muscles contracting will not by itself improve the patient’s condition. For benefit to be obtained, RTUS must be used in conjunction with good clinical skills, both in assessment and facilitation (Chipchase, Thoirs et al. 2009). It should be considered an adjunct to physiotherapy assessment and treatment, not as a treatment method (Hides, Richardson et al. 1998). The physiotherapists at bounceREHAB have comprehensive training in the use of RTUS by leading physiotherapy clinicians in Australia.
The use of Real Time Ultra Sound techniques have been successful in the assessment and feedback for patients with lower back pain. The main emphasis must be on RTUS being an adjunct to assessment and treatment, with good clinical skills remaining of paramount importance. RTUS has the potential to provide tremendous benefit to the population but it is important that it is performed by qualified and highly skilled clinicians such as those at bounceREHAB.
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