Ruth M. Maher

Quantification of Dry Needling and Posture Effects on Myofascial Trigger Points Using Ultrasound Shear-Wave Elastography

OBJECTIVES To determine (1) whether the shear modulus in upper trapezius muscle myofascial trigger points (MTrPs) reduces acutely after dry needling (DN), and (2) whether a change in posture from sitting to prone affects the shear modulus. DESIGN Ultrasound images were acquired in B mode with a linear transducer oriented in the transverse plane, followed by performance of shear-wave elastography (SWE) before and after DN and while sitting and prone. SETTING University. PARTICIPANTS Women (N=7; mean age ± SD, 46±17y) with palpable MTrPs were recruited. INTERVENTION All participants were dry needled in the prone position using solid filament needles that were inserted and manipulated inside the MTrPs. SWE was performed before and after DN in the sitting and prone positions. MAIN OUTCOME MEASURE MTrPs were evaluated by shear modulus using SWE. RESULTS Palpable reductions in stiffness were noted after DN and in the prone position. These changes were apparent in the shear modulus map obtained with ultrasound SWE. With significant main effects, the shear modulus reduced from before to after DN (P<.01) and from the sitting to the prone position (P<.05). No significant interaction effect between time and posture was observed. CONCLUSIONS The shear modulus measured with ultrasound SWE reduced after DN and in the prone position compared with sitting, in agreement with reductions in palpable stiffness. These findings suggest that DN and posture have significant effects on the shear modulus of MTrPs, and that shear modulus measurement with ultrasound SWE may be sensitive enough to detect these effects.

Reliability of ultrasound shear-wave elastography in assessing low back musculature elasticity in asymptomatic individuals

Patients with low back pain commonly exhibit impaired morphology and function of spinal musculature that may be quantifiable using shear-wave elastography (SWE). The purpose of this study was to assess the intra-rater and test-retest reliability of SWE elasticity measures of the lumbar erector spinae and multifidus muscles during rest and differing levels of contraction in asymptomatic individuals. This single-group repeated-measures design involved a baseline measurement session and a follow-up session 3 days later. The lumbar multifidus was imaged at rest and during three levels of contraction (minimal, moderate, and maximum). The lumbar erector spinae (illiocostalis and longissimus muscles) were imaged at rest only. Overall reliability estimates were fair to excellent with ICCs ranging from 0.44 to 0.92. Reliability was higher in the lumbar multifidus muscles than the erector spinae muscles, slightly higher during contraction than during rest, and substantially improved by using the mean of 3 measurements. By reliably quantifying impaired spinal musculature, SWE may facilitate an improved understanding of the etiology and treatment of low back pain and other muscle pain-related conditions such as trigger points and fibromyalgia.

Does Transvaginal Neuromuscular Electrical Stimulation Elicit a Pelvic Floor Muscle Contraction? A Pilot Study Using Ultrasonography in Healthy Women

Objective:Neuromuscular electrical stimulation (NMES) of the pelvic floor musculature (PFM) is a popular adjunctive intervention to pelvic floor exercises in those with urinary incontinence. The purpose of this study was to assess if transvaginal NMES (TvNMES) elicits a PFM contraction in supine or standing position and if a contraction can be verified with ultrasound imaging. Study Design:Repeated design study in which all participants experienced TvNMES in 2 randomly ordered positions of supine and standing. Methods and Measurement:Six healthy nulliparous women (mean age [SD], 24.8 [2.6] y) were recruited for this pilot study. All gave informed consent and completed a bladder filling protocol to allow for delineation of the bladder from the pelvic floor during ultrasound imaging. Participants used vaginal electrodes and were encouraged to increase intensity to a level of tolerable discomfort. Ultrasound imaging was used to assess the effect on the PFM. Results:All participants reported the perception of PFM contraction; however, ultrasound imaging confirmed this in only 1 participant in standing position. This participant tolerated higher intensities in the standing and supine positions than the other participants. Conclusion:Participant report of a PFM contraction was unreliable. Vaginal space restricts the size and orientation of the stimulating surface area; consequently, current density can cause discomfort, which limits the effectiveness of stimulation. On the basis of these findings, physical therapists should assess patients during TvNMES via observation with ultrasound imaging, or visible inspection of the perineum to ensure a PFM contraction is occurring.