Changes of skin electrical potential in acupoints from Ren Mai and Du Mai conduits during Qigong practice: Documentation of a clinical phenomenon

Qigong is a therapeutic method of traditional Chinese medicine (TCM) that combines slow, soft movements and postures with breath control and a special mental state of ‘awareness’. TCM holds that the practice of Qigong promotes the ‘circulation of qi’ in the human body, the ‘flow’ of upward yang qi and downward yin qi to establish ‘balance’. In Western terms, this may be generally equivalent to vegetative homeostasis and the emotionally balanced state induced thereby. Researchers have often attempted to evaluate the functional movements of qi using measurements of the skin's electrical resistance. However, these methodologies have proven difficult to gauge, validate, repeat, and interpret. We aimed to overcome these limitations by measuring the skin's electrical potential between two points of the same system. The main goal of this study was to assess the skin's electrical potential changes in acupoints from the Ren Mai and Du Mai conduits, or meridians, as well as in other points of interest, during Qigong practice. While participants performed a specific Qigong exercise called ‘White Ball’, we observed significant changes in the skin electrical potential on Mìngmén (GV 4), Shèndáo (GV 11) and Baihuì (GV 20), from the Du Mai conduit, as well as on Huiyin (CV 1), Qìhai (CV 6), Zhongwan (CV 12) and Dànzhong (CV 17), from Ren Mai. These observations are in accordance with TCM theory and may contribute to the explanation of the vegetative physiological changes that are associated with ‘qi flow’ in TCM.     

女性轻度盆底功能障碍的非手术治疗

目的探讨电刺激生物反馈治疗对轻度盆底功能障碍患者肌肉功能恢复情况和临床疗效。方法选取2011年1月至2012年12月在武警湖北省总队医院就诊的120名轻度尿失禁和性功能障碍患者,采用随机数字表法分成对照组和实验组,给予对照组凯格尔运动进行盆底肌肉训练3个月,对实验组进行电刺激生物反馈治疗3个疗程。结果治疗后实验组盆底肌最大收缩电位、Ⅰ类肌平均肌电位和Ⅱ类肌平均肌电位以及盆底肌Ⅰ类肌肌力和Ⅱ类肌肌力高于对照组,差异均有统计学意义（t值分别为4．523、1．321、1．894、3．263、4．236,均P〈0．05）。实验组总有效率（86．67％）高于对照组（61．67％）,经比较有显著性差异（x2=9．786,P〈0．05）。结论电刺激生物反馈疗法对轻度盆底功能障碍患者具有明显的疗效,且方便安全,无任何副作用．容易被广大患者接受,值得推广。     

Muscular activation changes in lower limbs after underwater gait training in Parkinson’s disease: A surface emg pilot study

BackgroundUnder water gait training (UT) has been proposed as an innovative rehabilitative strategy for the treatment of axial disorders in Parkinson Disease (PD) patients, in particular for balance and gait impairment. However, the basis for the improvement is unclear.Research questionThe aim of this study was to evaluate improvements in the muscular activation in the lower limbs in a cohort of PD patients after UT.MethodsTen PD participants in the “off” state and 10 controls (mean ± standard deviation of age and BMI were respectively: 71 ± 6 years, 28 ± 3 kg/m²; 65.5 ± 7 years, 28 ± 3 kg/m²) were enrolled in the study. After signing informed consent, they walked barefoot at their preferred speed on a 10 m walkway, before and after UT. The electrical activity of four muscles were collected bilaterally by means of a surface electromyography system (sEMG), two force plates and a motion capture system. All signals were synchronized in time with the gait cycle. The sEMG activity of Rectus Femoris (RF), Tibialis Anterior (TA), Biceps Femoris (BF) and Gastrocnemius Lateralis (GL) were acquired. The average from each signal was used to extract the peak of the Envelope (PoE) and its occurrence with respect to the gait cycle (PoPE%). Time and space parameters were determined.ResultsOur results showed that UT in PD patients improved the muscle’s recruitment pattern towards normal. The PD patients POPE% was comparable with the one of the controls (TA: 20–35 %, 75–80 % of gait cycle; GL: 0–15 %, 25–45 %, 85–100 % of gait cycle) after UT on each muscle with the exception of BF. The muscle co-activation plots failed to show improvement in line with the muscle activation.SignificanceThese results suggest that the muscle activation improvement with UT in PD participants might be due to a reorganisation at the executive rather than at the command level.     

CMAP scan discontinuities: Automated detection and relation to motor unit loss

ObjectiveTo evaluate an automated method that extracts motor unit (MU) information from the CMAP scan, a high-detail stimulus–response curve recorded with surface EMG. Discontinuities in the CMAP scan are hypothesized to result from MU loss and reinnervation.MethodsWe introduce the parameter D50 to quantify CMAP scan discontinuities. D50 was compared with a previously developed manual score in 253 CMAP scans and with a simultaneously obtained motor unit number estimate (MUNE) in 173 CMAP scans. The effect of MU loss on D50 was determined with a simulation model.ResultsWe found a high agreement (sensitivity = 86.8%, specificity = 96.6%) between D50 and the manual score. D50 and MUNE were significantly correlated below 80 MUs (r = 0.65, n = 68, p < 0.001), but not when MUNE was larger than 120 MUs (r = 0.23, n = 59, p = 0.08).ConclusionsDiscontinuities in the CMAP scan as expressed by a decreased D50 are related to significant MU loss. The determination of D50 is objective, quantitative, and less time-consuming than both manual scoring and many existing MUNE methods.SignificanceD50 is potentially useful to monitor neurogenic disorders and moderate to severe MU loss.     

Corticomuscular coherence in acute and chronic stroke

ObjectiveMotor recovery after stroke is attributed to neuronal plasticity, however not all post-stroke neuronal changes relate to regaining fine motor control. Corticomuscular coherence (CMC) is a measure allowing to trace neuronal reorganizations which are functionally relevant for motor recovery. Contrary to previous studies which were performed only in chronic stage, we measured CMC in patients with stroke at both acute and chronic stroke stages.MethodsFor the detection of CMC we used multichannel EEG and EMG recordings along with an optimization algorithm for the detection of corticomuscular interactions.ResultsIn acute stroke, the CMC amplitude was larger on the unaffected side compared to the affected side and also larger compared to the unaffected side in the chronic period. Additionally, CMC peak frequencies on both sides decreased in the acute compared to the chronic period and to control subjects. In chronic stage, there were no inter-hemispheric or group differences in CMC amplitude or frequency.ConclusionsThe changes in CMC parameters in acute stroke could result from a temporary decrease in inhibition, which normalizes in the course of recovery. As all patients showed very good motor recovery, the modulation of CMC amplitude and frequency over time might thus reflect the process of motor recovery.SignificanceWe demonstrate for the first time the dynamical changes of corticomuscular interaction both at acute and chronic stage of stroke.     

Innervation zone locations in 43 superficial muscles: Toward a standardization of electrode positioning

Introduction: We describe the innervation zone (IZ) location in 43 muscles to provide information for appropriate positioning of bipolar electrodes for clinical and research applications. Methods: The IZ was studied in 40 subjects (20 men and 20 women) using multichannel surface electromyography (sEMG). Signal quality was checked visually to identify motor unit action potentials and estimate muscle fiber conduction velocity. Results: Results in 33 muscles were classified as excellent or good, because it was possible to identify an area which is favorable for appropriate positioning of an electrode pair without the need to previously determine the IZ location. Conclusions: Knowledge of IZ location will increase standardization and repeatability of sEMG measures. Muscle Nerve 49 :413–421, 2014     

Anconeus motor unit number estimates using decomposition‐based quantitative electromyography

Introduction: Motor unit number estimates (MUNEs) provide important information in health, aging, and disease, and can be determined using decomposition‐enhanced spike‐triggered averaging (DE‐STA). Discrimination of surface‐detected motor unit potentials (S‐MUPs) has been limited to contractile forces of ∽30% maximum voluntary contraction (MVC), which is insufficient to recruit a representative sample of the entire MU pool in most muscles. Unique features of the anconeus may permit MUNEs at high muscle activation levels. Methods: In 10 men (25 ± 3 years), anconeus MUNEs were performed using DE‐STA at 10%, 30%, and 50% root‐mean‐square of MVC (RMS_MVC). Results: The mean compound muscle action potential of the anconeus was ∽6 mV, and average S‐MUP amplitudes were ∽100 μV, 145 μV, and 235 μV at 10%, 30%, and 50% RMS_MVC, resulting in low average MUNEs of 58, 38, and 25, respectively. Conclusions: Elbow extensor force–EMG relationships suggest full recruitment of the anconeus MU pool at 50% RMS_MVC, thus providing a representative sample for MUNE. Muscle Nerve 50 : 52–59, 2014