Repeatability of measuring sciatic nerve excursion during a modified passive straight leg raise test with ultrasound imaging

Sciatic nerve excursion during a modified passive straight leg raise test in asymptomatic participants and participants with spinally referred leg pain

“…In the present study, it was not possible to analyse the nerve excursion at the nerve root since ultrasound waves are strongly reflected by bone (Jacobson and van Holsbeeck, 1998), thus the underlying nerve cannot be viewed. Whilst it is likely that changes locally will have consequences to more distal excursion since the nerve is continuous throughout its connective tissue elements, the differences may not be sufficiently large to be detected by this method of analysis since error measures (smallest detectable difference) were found to be in the region of 2 mm (Ridehalgh et al, 2012), therefore differences of less than this may not be revealed.…”

“…In addition, subjects were required to have a normal neurological integrity test (detailed under procedure) and full range of motion of the lower limb and lumbar spine. The same participants took part in a previously published study on the reliability of the technique and normative values for excursion (Ridehalgh et al, 2012. Ethics approval was gained from the Faculty of Health and Social Sciences Research Ethics and Governance Committee of the host university.…”

“…3). The detailed description of the crosscorrelation procedure can be found in Ridehalgh et al (2012).…”

“…The introduction and availability of ultrasound imaging (UI) into analysing tissue mechanics has led to an increase in the understanding of nerve mechanics (Dilley et al, 2001;Ellis et al, 2012;Ridehalgh et al, 2012;Boyd and Dilley et al, 2014;Ridehalgh et al, 2014). Recently, nerve excursion during neurodynamic testing has been investigated in both the upper (Coppieters et al, 2009) and lower limb (Ellis et al, 2012;Ridehalgh et al, 2014).…”

Sciatic nerve stiffness is not changed immediately after a slump neurodynamics technique

“…However, to our knowledge, such benefits in humans have never been confirmed, in vivo. The effects of neurodynamics techniques on the peripheral nerves have been reported by several ex vivo 3,4 and in vivo studies 5,6 . Investigations using animal models have shown the viscoelastic behaviour of peripheral nerves, showing for instance a 30% reduction in stress relaxation after 5 min of constant strain (i.e.…”