[Effect of Dry Needling Stimulation of Myofascial Trigger Point on Sample Entropy of Electromyography of Gastrocnemius Injured Site in Rats].

OBJECTIVE: To attempt to establish an objective quantitative indicator to characterize the trigger point activity, so as to evaluate the effect of dry needling on myofascial trigger point activity. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into blank control group, dry needling (needling) group, stretching exercise (stretching) group and needling plus stretching group (n＝6 per group). The chronic myofascial pain (trigger point) model was established by freedom vertical fall of a wooden striking device onto the mid-point of gastrocnemius belly of the left hind-limb to induce contusion, followed by forcing the rat to make a continuous downgrade running exercise at a speed of 16 m/min for 90 min on the next day which was conducted once a week for 8 weeks. Electromyography (EMG) of the regional myofascial injured point was monitored and recorded using an EMG recorder via electrodes. It was considered success of the model if spontaneous electrical activities appeared in the injured site. After a 4 weeks' recovery, rats of the needling group were treated by filiform needle stimulation (lifting-thrusting-rotating) of the central part of the injured gastrocnemius belly (about 10 mm deep) for 6 min, and those of the stretching group treated by holding the rat's limb to make the hip and knee joints to an angle of about 180°, and the ankle-joint about 90° for 1 min every time, 3 times altogether (with an interval of 1 min between every 2 times). The activity of the trigger point was estimated by the sample entropy of the EMG signal sequence in reference to Richman's and Moorman's methods to estimate the curative effect of both needling and exercise. RESULTS: After the modeling cycle, the mean sample entropies of EMG signals was significantly decreased in the model groups (needling group [0.034±0.010], stretching group [0.045±0.023], needling plus stretching group [0.047±0.034]) relevant to the blank control group (0.985±0.196, P<0.01). After the treatment, the mean sample entropy of EMG signals was evidently increased in both needling (0.819±0.088), stretching (0.532±0.25) and needling plus stretching (0.810±0.117) groups (P<0.01). The mean sample entropy of the needling and needling plus stretching groups were significantly higher than that of the stretching group (P<0.01), without remarkable difference between the two needling groups in the mean sample entropy (P>0.05), suggesting a better efficacy of dry needling in easing trigger point activity. CONCLUSION: Dry needling is able to relieve myofascial trigger point activity in rats, which is better than that of simple passive stretching therapy.

Evidence for Dry Needling in the Management of Myofascial Trigger Points Associated With Low Back Pain: A Systematic Review and Meta-Analysis.

OBJECTIVE: To evaluate the current evidence of the effectiveness of dry needling of myofascial trigger points (MTrPs) associated with low back pain (LBP). DATA SOURCES: PubMed, Ovid, EBSCO, ScienceDirect, Web of Science, Cochrane Library, CINAHL, and China National Knowledge Infrastructure databases were searched until January 2017. STUDY SELECTION: Randomized controlled trials (RCTs) that used dry needling as the main treatment and included participants diagnosed with LBP with the presence of MTrPs were included. DATA EXTRACTION: Two reviewers independently screened articles, scored methodologic quality, and extracted data. The primary outcomes were pain intensity and functional disability at postintervention and follow-up. DATA SYNTHESIS: A total of 11 RCTs involving 802 patients were included in the meta-analysis. Results suggested that compared with other treatments, dry needling of MTrPs was more effective in alleviating the intensity of LBP (standardized mean difference [SMD], -1.06; 95% confidence interval [CI], -1.77 to -0.36; P=.003) and functional disability (SMD, -0.76; 95% CI, -1.46 to -0.06; P=.03); however, the significant effects of dry needling plus other treatments on pain intensity could be superior to dry needling alone for LBP at postintervention (SMD, 0.83; 95% CI, 0.55-1.11; P<.00001). CONCLUSIONS: Moderate evidence showed that dry needling of MTrPs, especially if associated with other therapies, could be recommended to relieve the intensity of LBP at postintervention; however, the clinical superiority of dry needling in improving functional disability and its follow-up effects still remains unclear.

Decreased Spontaneous Electrical Activity and Acetylcholine at Myofascial Trigger Spots after Dry Needling Treatment: A Pilot Study.

OBJECTIVE: The aims of this study are to investigate the changes in spontaneous electrical activities (SEAs) and in acetylcholine (ACh), acetylcholine receptor (AChR), and acetylcholine esterase (AChE) levels after dry needling at myofascial trigger spots in model rats. MATERIALS AND METHODS: Forty-eight male Sprague-Dawley rats were divided into four groups. Thirty-six rats were assigned to three model groups, which underwent MTrSs modeling intervention. Twelve rats were assigned to the blank control (BC) group. After model construction, the 36 model rats were randomly subdivided into three groups according to treatment: MTrSs model control (MC) and two dry needling groups. One dry needling group received puncturing at MTrSs (DN-M), whereas the other underwent puncturing at non-MTrSs (DN-nM). Dry needling treatment will last for two weeks, once a week. SEAs and ACh, AChR, and AChE levels were measured after one-week rest of dry needling treatment. RESULTS: The amplitudes and frequencies of endplate noise (EPN) and endplate spike (EPS) significantly decreased after dry needling treatment in the DN-M group. Moreover, ACh and AChR levels significantly decreased, whereas AChE significantly increased after dry needling treatment in the DN-M group. CONCLUSION: Dry needling at the exact MTrSs is more effective than dry needling at non-MTrSs.