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Abstract

Objectives To use ultrasound imaging to show how the needles in dry needling applied in the carpal tunnel can reach the transverse carpal ligament, acting on it in the form of traction-stretching when the fascial winding technique is performed. The potential associated risks are also assessed. Design Validation study. Participants Healthy volunteers (n = 18). Methods Four dry needling needles were applied to the carpal tunnel, only using anatomical references, according to the original approach known as “four-pole carpal dry needling”, and manipulating the needles following the so-called fascial winding technique according to the authors, in the form of unidirectional rotation. An ultrasound recording of the distance reached was then performed, and compared with the mechanical action achieved on the transverse carpal ligament. Results 93.1% of the needles placed came into contact with the transverse carpal ligament with traction-stretching of the ligament observed when the needles were manipulated with the fascial winding technique in 80.6%. The mean distance from the tip of the needle to the median nerve was 3.75 mm, with CI95% [3.10, 4.41] and it was 7.78 mm with CI95% [6.64, 8.91] to the ulnar artery. Pain immediately after the technique concluded was of mild intensity, almost nil 10 min later, and non-existent after one week. Conclusion Dry needling with fascial winding technique in the carpal tunnel using the four-pole carpal dry needling approach is valid for reaching and traction of the transverse carpal ligament, and may stretch it and relax it. It is also safe with regard to the median nerve and ulnar artery, with a very mild level of pain.

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... 20 Ultrasound has been utilized in previous studies to confirm needle placement, but not of the TP muscle. [21][22][23] Therefore, given the clinical relevance of the TP muscle for normal foot and ankle function, the purpose of this study was to assess the accuracy of needle placement in the TP muscle and determine the needle placement in relation to the neurovascular structures located within the deep compartment. ...
... Previous studies utilizing ultrasound imaging to validate needle placement have included a sample size of 10-20 individuals; therefore, this studyincluded a sample size of 20 individuals. 21,22 ...
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Background: The tibialis posterior (TP) muscle plays an important role in normal foot function. Safe, efficacious therapeutic approaches addressing this muscle are necessary; however, the location of the muscle in the deep posterior compartment can create challenges. Purpose: The purpose of this study was to assess the accuracy of needle placement in the TP muscle and determine the needle placement in relation to the neurovascular structures located within the deep compartment. Design: Cross Sectional Study. Methods: Needle placement and ultrasound imaging were performed on 20 healthy individuals. A 50 mm or 60 mm needle was inserted between 30 - 50% of the tibial length measured from the medial tibiofemoral joint. The needle was inserted in a medial to lateral direction into the right extremity with the patient in right side lying. Placement of the needle into the TP muscle was verified with ultrasound imaging, and the shortest distance from the needle to the posterior tibial artery and tibial nerve was measured. The depth from the skin to the superficial border of the TP muscle was also measured. Results: Ultrasonography confirmed the needle filament was inserted into the TP muscle in all 20 individuals and did not penetrate the neurovascular bundle in any individual. The mean distance from the needle to the tibial nerve and posterior tibial artery was 10.0 + 4.7 mm and 10.2 + 4.7 mm respectively. The superficial border of the TP muscle from the skin was at a mean depth of 25.8 + 4.9 mm. Conclusion: This ultrasound imaging needle placement study supports placement of a solid filament needle into the TP muscle with avoidance of the neurovascular structures of the deep posterior compartment when placed from a medial to lateral direction at 30-50% of the tibial length. Level of evidence: 2b.
... While most commonly DN is directed at trigger points [2], its contemporary use also targets tendons [3,4], entheses [5], periosteum [6], scar tissue [7], and fascia [8] to reduce local and referred pain, lessen spasticity [9,10], eliminate neural entrapments [11], increase range of motion [12], or normalize muscle activation patterns [13]. DN is a safe anatomy-driven procedure [14], although there are inherent risks when safety precautions are not taken into account [15][16][17][18]. ...
Article
Background Carpal tunnel syndrome (CTS) is a disorder with a prevalence of about 5.8% for females and 0.6% for males. This study aims to determine whether intramuscular stimulation (IMS) to the pronator teres muscle subsequently reduces the severity of clinical parameters and the diameter of the median nerve. Methods Seventy-five individuals with a cross-sectional diameter of the median nerve of more than 2 mm were included in this randomized clinical trial. Thirty-seven individuals received IMS to the pronator teres muscle with a depth of up to 45-50 mm. The 38 individuals in the control group received an acupuncture needle at Li11 with a depth of 4-5 mm. Both groups had 7 treatments within 7 weeks. The primary outcome was the cross-section of the median nerve in the carpal tunnel. Additionally, Phalen’s test, Tinel’s sign, VAS for pain intensity, and pincer grip strength were measured. Results Both IMS subjects and controls showed significant reductions in the cross-section of the median nerve from baseline to follow-up (p<0.001 and p=0.002 respectively). The IMS group had the largest change, but the difference in change between the groups was not significant (p=0.39). On all clinical tests, IMS subjects showed significant improvement from baseline compared with the control group (largest p=0.002). Conclusion In this study we found that IMS to the pronator teres muscle significantly improved all clinical variables measured, compared with the group receiving acupuncture. Furthermore, the cross-section of the median nerve reduced over time for both groups. IMS may be a low-risk alternative while patients are waiting for surgery. TRIAL REGISTRATION Clinicaltrials.gov Identifier: NCT01102868. Retrospectively registered: March 29th 2010.
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Background: In the context of ultrasound-guided peripheral nerve blocks (regional anesthesia), clear visualization of the needle tip and the target structure are mandatory for the performance of a safe puncture and injection. The purpose of this in vitro study was to analyze the visualization of different forms of needle tips and calibers of cannulas in a phantom simulating human tissue, with the help of a standardized image analysis system. Different depths and angles of the puncture needle in relation to the ultrasound probe were tested. Material and methods: Cannula needles established for use in regional anesthesia with different surfaces, diameters and needle tip form in 23 different combinations were analyzed. A gelatine-based phantom was used to simulate human tissue. The standardized visualization of the needle tip with the ultrasound probe was performed in plane at different angles (30°, 45° and 60°), depths of penetration (1 cm, 2 cm and 3 cm) and two different alignments of the cannula needle lumen to the ultrasound probe (0° and 180°). The screenshots of the ultrasound pictures were analyzed by quantifying the pixel brightness around the needle tip (region of interest) with a standardized software (score 0-255). Results: In this study 1104 ultrasound images of cannula needles were analyzed. Diminished scores (reduced pixel brightness) of the needle tips were documented with increasing distance from the ultrasound probe. Comparison of punctures at angles of 30° and 45° showed no differences in needle tip visibility (same scores) but punctures at an angle of 60° were poorly visualized compared with 30° and 45° (mean scores 87.90 ± 11.60 vs. 78.40 ± 12.07, p < 0.001 and 81.85 ± 11.79 vs. 78.40 ± 12.07, p < 0.001, respectively). The direct alignment of the cannula lumen towards the ultrasound probe (0°) was significantly more easily visualized when compared with the reverse alignment of 180° (mean scores 86.90 ± 12.74 vs. 84.80 ± 11.66, p = 0.003, respectively). No differences in visibility were detected between the different cannula needle diameters examined. The Sprotte cannula showed the best visibility score with respect to the cut of the needle tip (mean score 89.40 ± 11.72). Conclusion: The visibility of cannulas in ultrasound scans depends on the ultrasound frequency, angle of the puncture in relation to the ultrasound probe and the depth of penetration. The results of this study showed that direct alignment of the cannula needle lumen towards the ultrasound probe (0°) independently improved needle tip visualization. This simple measure allows a significant improvement in the safe performance of ultrasound-guided peripheral nerve blocks.
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We would like to welcome Dr. Li-Wei Chou, MD, PhD as our newly appointed contributing author. Dr. Chou is Assistant Professor at China Medical University in Taichung, Taiwan and he has an impressive publication record with many research studies and book chapters. The current overview includes several articles comparing dry needling (DN) to acupuncture with sharply contrasting points of view. Several basic studies shed further light on the nature of myofascial pain, myalgia, fascia and examination techniques, such as sonoelastography. Neuroimaging studies demonstrated microstructural abnormalities in brain gray matter of chronic myofascial pain patients, which is an important new finding. As usual, many manual TrP papers and DN papers were published in the past several months.
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With the growth of ultrasound-guided regional anesthesia, so has the requirement for training tools to practice needle guidance skills and evaluate echogenic needles. Ethically, skills in ultrasound-guided needle placement should be gained in a phantom before performance of nerve blocks on patients in clinical practice. However, phantom technology is varied, and critical evaluation of the images is needed to understand their application to clinical use. Needle visibility depends on the echogenicity of the needle relative to the echogenicity of the tissue adjacent the needle. We demonstrate this point using images of echogenic and nonechogenic needles in 5 different phantoms at both shallow angles (20 degrees) and steep angles (45 degrees). The echogenicity of phantoms varies enormously, and this impacts on how needles are visualized. Water is anechoic, making all needles highly visible, but does not fix the needle to allow practice placement. Gelatin phantoms and Blue Phantoms provide tactile feedback but have very low background echogenicity, which greatly exaggerates needle visibility. This makes skill acquisition easier but can lead to false confidence in regard to clinical ability. Fresh-frozen cadavers retain much of the textural feel of live human tissue and are nearly as echogenic. Similar to clinical practice, this makes needles inserted at steep angles practically invisible, unless they are highly echogenic. This review describes the uses and pitfalls of phantoms that have been described or commercially produced.
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Needle visualization is important for safe and successful Ultrasound-guided peripheral nerve block. However, accurate and consistent visualization of the needle tip can be difficult to achieve. This review article describes many of the challenges affecting needle Visualization, summarizes the relevant literature oil ultrasound imaging of needles, and offers practical strategies for improving needle tip visibility. Finally, future directions for research and development are suggested. Reg Anesth Pain Med 2008;33:532-544.
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This study was designed to investigate the effects of injection with a local anesthetic agent or dry needling into a myofascial trigger point (TrP) of the upper trapezius muscle in 58 patients. Trigger point injections with 0.5% lidocaine were given to 26 patients (Group I), and dry needling was performed on TrPs in 15 patients (Group II). Local twitch responses (LTRs) were elicited during multiple needle insertions in both Groups I and II. In another 17 patients, no LTR was elicited during TrP injection with lidocaine (9 patients, group Ia) or dry needling (8 patients, group IIa). Improvement was assessed by measuring the subjective pain intensity, the pain threshold of the TrP and the range of motion of the cervical spine. Significant improvement occurred immediately after injection into the patients in both group I and group II. In Groups Ia and Ib, there was little change in pain, tenderness or tightness after injection. Within 2-8 h after injection or dry needling, soreness (different from patients' original myofascial pain) developed in 42% of the patients in group I and in 100% of the patients in group II. Patients treated with dry needling had postinjection soreness of significantly greater intensity and longer duration than those treated with lidocaine injection. The author concludes that it is essential to elicit LTRs during injection to obtain an immediately desirable effect. TrP injection with 0.5% lidocaine is recommended, because it reduces the intensity and duration of postinjection soreness compared with that produced by dry needling.
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The mechanism of action of acupuncture remains largely unknown. The reaction to acupuncture needling known as 'de qi', widely viewed as essential to the therapeutic effect of acupuncture, may be a key to understanding its mechanism of action. De qi includes a characteristic needling sensation, perceived by the patient, and 'needle grasp' perceived by the acupuncturist. During needle grasp, the acupuncturist feels pulling and increased resistance to further movement of the inserted needle. We hypothesize that 1) needle grasp is due to mechanical coupling between the needle and connective tissue with winding of tissue around the needle during needle rotation and 2) needle manipulation transmits a mechanical signal to connective tissue cells via mechanotransduction. Such a mechanism may explain local and remote, as well as long-term effects of acupuncture.
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In a landmark hypothesis-generating study, Todd et al found that a difference of approximately 13 mm (95% confidence interval [CI] 10 to 17 mm) on a visual analog scale (VAS) represented the minimum change in acute pain that was clinically significant in a cohort of trauma patients. We test the hypothesis that the minimum clinically significant change in pain as measured by the VAS in an independent, more heterogeneous validation cohort is approximately 13 mm. This was a prospective, observational cohort study of adults presenting to 2 urban emergency departments with pain. At 30-minute intervals during a 2-hour period, patients marked a VAS and were asked if their pain was "much less," "a little less," "about the same," "a little more," or "much more." All data were obtained without reference to prior VAS scores. The minimum clinically significant change in pain was defined a priori as the difference in millimeters between the current and immediately preceding VAS scores when "a little more" or "a little less pain" was reported. Ninety-six patients enrolled in the study, providing 332 paired pain measurements. There were 141 paired measurements designated by patients as "a little less" or "a little more" pain. The mean clinically significant difference between consecutive ratings of pain in the combined "little less" or "little more" groups was 13 mm (95% CI 10 to 16 mm). The difference between this finding and that of Todd et al was 0 mm (95% CI -4 to 4 mm). These data are virtually identical to previous findings indicating that a difference of 13 mm on a VAS represents, on average, the minimum change in acute pain that is clinically significant.
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Reliable and valid measures of pain are needed to advance research initiatives on appropriate and effective use of analgesia in the emergency department (ED). The reliability of visual analog scale (VAS) scores has not been demonstrated in the acute setting where pain fluctuation might be greater than for chronic pain. The objective of the study was to assess the reliability of the VAS for measurement of acute pain. This was a prospective convenience sample of adults with acute pain presenting to two EDs. Intraclass correlation coefficients (ICCs) with 95% confidence intervals (95% CIs) and a Bland-Altman analysis were used to assess reliability of paired VAS measurements obtained 1 minute apart every 30 minutes over two hours. The summary ICC for all paired VAS scores was 0.97 [95% CI = 0.96 to 0.98]. The Bland-Altman analysis showed that 50% of the paired measurements were within 2 mm of one another, 90% were within 9 mm, and 95% were within 16 mm. The paired measurements were more reproducible at the extremes of pain intensity than at moderate levels of pain. Reliability of the VAS for acute pain measurement as assessed by the ICC appears to be high. Ninety percent of the pain ratings were reproducible within 9 mm. These data suggest that the VAS is sufficiently reliable to be used to assess acute pain.
Article
Acupuncture needle manipulation gives rise to "needle grasp," a biomechanical phenomenon characterized by an increase in the force necessary to pull the needle out of the tissue (pullout force). This study investigates the hypothesis that winding of connective tissue, rather than muscle contraction, is the mechanism responsible for needle grasp. We performed 1) measurements of pullout force in humans with and without needle penetration of muscle; 2) measurements of pullout force in anesthetized rats, with and without needle rotation, followed by measurements of connective tissue volume surrounding the needle; 3) imaging of rat abdominal wall explants, with and without needle rotation, using ultrasound scanning acoustic microscopy. We found 1) no evidence that increased penetration of muscle results in greater pullout force than increased penetration of subcutaneous tissue; 2) that both pullout force and subcutaneous tissue volume were increased by needle rotation; 3) that increased periodic architectural order was present in subcutaneous tissue with rotation, compared with no rotation. These data support connective tissue winding as the mechanism responsible for the increase in pullout force induced by needle rotation. Winding may allow needle movements to deliver a mechanical signal into the tissue and may be key to acupuncture's therapeutic mechanism.
Article
Acupuncture meridians traditionally are believed to constitute channels connecting the surface of the body to internal organs. We hypothesize that the network of acupuncture points and meridians can be viewed as a representation of the network formed by interstitial connective tissue. This hypothesis is supported by ultrasound images showing connective tissue cleavage planes at acupuncture points in normal human subjects. To test this hypothesis, we mapped acupuncture points in serial gross anatomical sections through the human arm. We found an 80% correspondence between the sites of acupuncture points and the location of intermuscular or intramuscular connective tissue planes in postmortem tissue sections. We propose that the anatomical relationship of acupuncture points and meridians to connective tissue planes is relevant to acupuncture's mechanism of action and suggests a potentially important integrative role for interstitial connective tissue.
Article
Acupuncture needle rotation has been previously shown to cause specific mechanical stimulation of subcutaneous connective tissue. This study uses acupuncture to investigate the role of mechanotransduction-based mechanisms in mechanically-induced cytoskeletal remodeling. The effect of acupuncture needle rotation was quantified by morphometric analysis of mouse tissue explants imaged with confocal microscopy. Needle rotation induced extensive fibroblast spreading and lamellipodia formation within 30 min, measurable as an increased in cell body cross sectional area. The effect of rotation peaked with two needle revolutions and decreased with further increases in rotation. Significant effects of rotation were present throughout the tissue, indicating the presence of a response extending laterally over several centimeters. The effect of rotation with two needle revolutions was prevented by pharmacological inhibitors of actomyosin contractility (blebbistatin), Rho kinase (Y-27632 and H-1152), and Rac signaling. The active cytoskeletal response of fibroblasts demonstrated in this study constitutes an important step in understanding cellular mechanotransduction responses to externally applied mechanical stimuli in whole tissue, and supports a previously proposed model for the mechanism of acupuncture involving connective tissue mechanotransduction.
Article
Although acupuncture-needle manipulation is an important component of acupuncture therapy, little information is currently available on whether or not specific types of needle manipulation produce different effects on the body. Bidirectional (back-and-forth) rotation is one of the most common forms of needle manipulation used in acupuncture practice. In this study, we hypothesized that bidirectional acupuncture needle rotation causes dose-dependent active cytoskeletal remodeling in connective tissue fibroblasts similar to that previously demonstrated with unidirectional rotation. Subcutaneous tissue explants from 18 mice were randomized to varying amounts of bidirectional rotation cycles (8-64) and rotation-cycle amplitude (180 degrees -720 degrees ) ex vivo for 30 minutes, followed by tissue fixation, confocal microscopy, and measurement of fibroblast cell body cross-sectional area. As with unidirectional rotation, fibroblasts responded to bidirectional rotation with extensive cell spreading and lamellipodia formation. Bidirectional needle rotation had a significant overall effect on fibroblast cell body cross sectional area (analysis of variance, p < 0.001). The cellular response to bidirectional rotation was nonmonotonic with maximal responses occurring within specific stimulus windows with regard to cycle amplitude and cycle number. These findings demonstrate that subtle differences in acupuncture-needle manipulation techniques can affect cellular responses in mouse subcutaneous connective tissue. Further studies will be needed to determine whether these connective-tissue responses are related to therapeutic effects.