Effects of vibration therapy on neuromuscular efficiency & features of the EMG signal based on endurance test

BackgroundVibration Therapy (VT) stimulate the muscle spindles, which in turn enhances its afferent activities.ObjectiveThe present study was designed to investigate the effect of VT at 23 and 35 Hz on muscle performance. The EMG features (six time-domain (TD) and four frequency-domain (FD)) and a new formula for computing neuromuscular performance were used as dependent variables to evaluate the effect of VT.MethodThe EMG recording was performed at 50% MVC during grip endurance test before and after VT. The EMG features were extracted out of raw EMG signals acquired from four forearm muscles, viz., flexor digitorum superficialis (FDS); flexor carpi ulnaris (FCU); extensor carpi radialis brevis (ECRB); and extensor carpi ulnaris (ECU) in supine position. Fatigue assessments were evaluated based on the pattern of TD and FD features.ResultsStatistical analysis showed a significant difference in the effect of vibration exposure frequency on IEMG (p < 0.001), MAV (p = 0.041), SSI (p = 0.032), and WL (p < 0.001) of FCU muscle. In addition, the greatest increase in neuromuscular efficiency (NME) was observed in the performance of ECRB after 35 Hz of VT and ECU muscles after 23 Hz of VT.ConclusionsThe features of EMG signals could be used for fatigue analysis. However, the slope based on the median frequency regression line may be the best feature for fatigue assessment.     

Surface electromyography and muscle force: limits in sEMG-force relationship and new approaches for applications

The estimation of the force generated by an activated muscle is of high relevance not only in biomechanical studies but also more and more in clinical applications in which the information about the muscle forces supports the physician's decisions on diagnosis and treatment. The surface electromyographic signal (sEMG) reflects the degree of activation of skeletal muscles and certain that the sEMG is highly correlated to the muscle force. However, the largest disadvantage in predicting the muscle force from sEMG is the fact that the force generated by a muscle cannot be directly measured non-invasively. Indirect measurement of muscle force goes along with other unpredictable factors which influence the detected force but not necessarily the sEMG data. In addition, the sEMG is often difficult to interpret correctly. The sEMG-force relationship has been investigated for a long time and numerous papers are available. This review shows the limitations in predicting the muscle force from sEMG signals and gives some perspectives on how these limitations could be overcome, especially in clinical applications, by using novel ways of interpretation.     

肌电控制及肌电信号的分析处理

肌电信号是一种与肢体运动直上关的生理电活动，它已成为人－机仿生系统理想的控制信号源。肌电控制系统动作自然、仿生性能好。本文以肌电假肢为例，论述了肌电控制的实现方法，并系统地介绍、评价了参数模型法、人工神经网络等时域和频域体表肌电信号分析处理技术。     

Unconditioned and conditioned muscular responses in patients with chronic back pain and chronic tension-type headaches and in healthy controls

Muscular tension is assigned an important role in the development and maintenance of chronic pain syndromes. It is seen as a psychophysiological correlate of learned fear and avoidance behavior. Basic theoretical models emphasize classical conditioning of muscular responses as a mechanism of pain chronification. However, the empirical basis for this field is very small. Our aim was to investigate muscular factors in relation to unconditioned and conditioned pain stimuli. An experimental study was conducted using a differential classical conditioning paradigm with 18 patients with chronic back pain (BP) and tension-type headache (TTH), and 18 healthy controls (HC). A high-pitched sound served as the CS+, paired with an intracutaneous electric pain stimulus (US), while a neutral sound was used as the CS−. Simultaneously, integrated surface electromyograms (iEMGs) were recorded for seven muscle sites. Our hypothesis was that the pain patients would demonstrate enhanced conditionability. Baseline values between patients (TTH, BP) and HC showed no significant differences. Although the perception and pain thresholds were balanced, both patient groups revealed a higher number of significant muscular responses to the pain stimulus (UR) than the HC. All participants showed significant conditioned muscular responses, however, the patients displayed a higher number than the healthy controls. Furthermore a significant relation was found between muscular responses and the experience of pain 1 day after the experiment. Muscular responses can be learned via classical conditioning. TTH and BP patients revealed a higher number of unconditioned and conditioned responses.     

EMG analysis of the late exteroceptive suppression period of temporal muscle activity in episodic and chronic tension-type headaches

EMG analysis of the late exteroceptive suppression period of the temporal muscle activity is discussed as comparative methodology in the assessment of patients suffering from chronic tension-type headache and from migraineurs. After electrical perioral trigeminal nerve stimulation during maximum voluntary jaw occlusion, early (ES1) and late (ES2) exteroceptive suppression periods can be registered above the temples using surface EMG recordings. In patients suffering from chronic tension-type headache the duration of the late suppression period is shortened (p less than 0.001) compared to migraineurs or controls. However, patients suffering from episodic tension-type headache display late suppression periods of temporal muscle activity of differing lengths.     

神经妥乐平联合神经阻滞治疗腰椎间盘突出致根性坐骨神经痛

目的 :神经妥乐平 (neurotropin ,NTP)是家兔皮肤接种牛痘病毒后局部炎症皮肤中提取的生物活性物质 ,本研究旨在观察该药及与神经阻滞疗法联合应用治疗腰椎间盘突出致根性坐骨神经痛的临床效果。方法 :CT或MRI证实的腰椎间盘突出、并有单侧坐骨神经痛的患者 10 2例 ,分 (1)神经阻滞组 (NB ,n =4 5 ) :骶管注射 +L2～ 5椎旁注射 ,每周 1次 ,连续 5周 ;(2 )神经阻滞 +神经妥乐平组 (NB +NTP组 ,n =35 ) :骶管注射 +L2～ 5椎旁注射同NB组 ,每周 1次 ,2周后骶管内追加NTP 6ml,其余同以往治疗 ,在行神经阻滞治疗间隙每天肌肉注射 3ml神经妥乐平。 5周治疗结束后进行疗效评价 ,并观察其中 16例患者治疗前后肌电图的变化 ;(3)神经妥乐平组 (NTP ,n =2 2 ) :前 2周仅给予口服非甾体类消炎止痛药物 (如莫比可、英太青 ) ,2周后开始予神经妥乐平 6ml/d肌肉注射共 2周 ,最后 1周改为 3ml/d肌注 ,比较治疗前后的疼痛缓解情况。结果 :(1)单独使用神经妥乐平可以明显缓解腰椎间盘突出引起的坐骨神经痛 (P <0 .0 5 ) ;(2 )神经妥乐平不仅能明显提高神经阻滞疗法缓解根性坐骨神经痛的作用 ,两者联合应用 ,还可明显缓解神经根受压所致的下肢麻木 (P <0 .0 1) ;(3)除极少数病例出现皮肤过敏反应 ,NTP用于治疗坐骨神经痛无     

EMG in common migraine: Changes in absolute and proportional EMG levels during real-life stress

The absolute and proportional EMG levels of the frontal, temporal, and corrugator muscles of 37 migraine patients and 37 matched controls were recorded during three experimental sessions: adaptation and real-life and experimental stress, both of long duration. Migraine patients did not show significantly different absolute EMG levels but had higher proportional EMG levels of the corrugator muscle than controls in each session. Migraine patients did not have different facial muscle responses to stress, and the two experimental groups reacted similarly to real-life and experimental stress. No relation was found between muscle activity and reported headache within 24 h after real-life stress. Increased EMG activity due to stress does not seem to be a significant cause of headache in common migraine as defined in this study, but rather a response to pain. Migraine patients with headache during stress showed lower muscle tension than patients without headache.     

Comparative analysis of core muscle activation according to the use of props and the different knee angle during the modified Pilates Hundred

BackgroundThere are not so many Pilates studies related to muscle activation. Since the effectiveness and efficiency of the Pilates Hundred to muscle activation has recently emerged, it is necessary to investigate the effects of the Pilates Hundred on core muscles.ObjectivesThe purpose of this study was to determine what difference occurs in the muscle activity, during the Pilates Hundred, to suggest the optimal props for muscle function improvement and then to provide data for the efficient exercise program.MethodsTwenty-eight men in their twenties who were able to fully conduct Pilates Hundred. According to the difference between the small tool application (no prop: NP, soft ball mini: SB, Pilates ring: PR) and the knee joint angle (90° and 180°), muscle activations of rectus abdominis (RA), external oblique (EO), rectus femoris (RF), lateral muscle (vastus lateralis: VL), medial muscle (vastus medialis: VM), biceps femoris (BF), and semitendinosus (ST) were measured by the using surface electromyography (EMG) while different exercise conditions.ResultsDuring Pilates Hundred, the use of tools was found to be more effective in activating the core muscle (NP < SB < PR). During Pilates Hundred, 180° of knee angle had more influence on core muscle activation than 90°, and knee angle and props use showed an interaction for activating core muscles.ConclusionThe Pilates Hundred with PR and 180° knee angle intervention can increase core muscle activation, and this leads to effective Pilates exercise program for those who need to enhance core muscle volume and function and to rehabilitate core muscles.     

成人格林-巴利综合征的临床和神经电生理分析

格林-巴利综合征(GBS)是临床上急性弛缓性瘫痪的常见原因,其病因和发病机制尚未明确,目前认为是感染所诱发的自身免疫性疾病.现将我院近5年来收治的36例成人GBS患者的临床及神经电生理改变进行分析,并对其病因及疗法加以探讨.