小儿格林巴利综合征27例肌电图及神经传导速度检测

目的探讨小儿格林巴利综合征(GBS)肌电图及神经传导速度检测的特征及临床意义。方法对27例GBS患儿的临床资料及实验室资料进行分析,并作针极肌电图(EMG)及神经传导速度(NCV)检测和分析,观察静息状态时自发电位,测定轻收缩时运动单位电位(MUP)的时限、波幅,大力收缩时的幕集相。测定运动、感觉神经的传导速度(MCV、SCV)及动作电位的末端潜伏期(ML)、波幅(AMP)、F波等。结果共检测73条肌肉、156条运动神经、81条感觉神经。EMG提示神经原性改变占74.1%;运动神经远端潜伏期(ML)延长占64.7%,MCV减慢占59.6%,AMP降低81.4%,F波异常占91.9%;SCV减慢占37.0%,伴波幅下降34.6%。结论小儿GBS存在广泛的周围神经损害,肌电图及神经传导速度检测对GBS的诊断、鉴别诊断、分型、随访及预后的评估有重要意义。     

Does scapular corrective taping alter periscapular muscle activity and 3-dimensional scapular kinematics? A systematic review

Study DesignThis is a systematic review.IntroductionScapular taping is widely used in the management of scapular dysfunction. However, its effects on the scapular kinematics and the electromyography (EMG) activity of the periscapular muscles are not clear.Purpose of the StudyThe purpose of the study was to systematically review the current literature to examine whether scapular corrective taping alters the EMG activity of the periscapular muscles and the 3-dimensional scapular kinematics.MethodMEDLINE and Web of Science databases were searched using specific mesh terms up to April 2018. A hand search was also conducted on the reference list of the included articles. A total of 157 studies were identified, and they were further analyzed for the eligibility to the systematic review. Studies that investigated the effects of scapular corrective taping on the EMG activity of the periscapular muscles and on the 3-dimensional scapular kinematics on patients with shoulder problems or asymptomatic subjects were eligible for the systematic review. The Cochrane Effective Practice and Organization of Care criteria were modified and used for the risk-of-bias assessment.ResultsEleven articles met the inclusion criteria and were included in the systematic review. Five studies investigated the effects of corrective taping on the scapular kinematics and 8 studies reported the effects of corrective taping on the EMG activity of the periscapular muscles. There was an agreement among the studies that scapular upward rotation is increased with the corrective taping, while there are inconsistent results concerning the scapular external rotation and posterior tilt. In addition, studies mostly reported that corrective taping decreases the activity of the upper trapezius, while it has conflicting effects on the activity patterns of other periscapular muscles.DiscussionScapular corrective taping was found to increase the scapular upward rotation; however, its effects on scapular external rotation and posterior tilt are controversial. It was also found that corrective taping might decrease the EMG activity of the upper trapezius, while it had no effects on the activity of lower trapezius, and its effects on other periscapular muscles were controversial.ConclusionThe results of the studies indicated that scapular corrective taping might alter the 3-dimensional scapular kinematics, while there are controversies about the effects of corrective taping on the EMG activity of the periscapular muscles. Further studies are needed to clarify the conflicts.     

Loads on the lumbar trunk during level walking

The goal of this study was to estimate the loads internal to the lumbar trunk that arise during level walking. To do this, (a) trunk muscle activities were calibrated in terms of muscle contraction force levels in a set of isometric exertions; (b) trunk muscle myoelectric activities were measured during level walking; and then (c) the muscle contraction forces that arose during walking were calculated from these measurements and calibrations. Lumbar trunk muscle myoelectric activities were quantified in 10 healthy young males. Myoelectric activities were monitored using eight bipolar surface electrode pairs placed around the trunk at the level of the third lumbar vertebrae. The subjects first performed four static weight-resisting tasks to calibrate muscle force/activity relationships. They then traversed a 8.25 m walkway three times each at cadences of 72 and 120 steps/min. A biomechanical model incorporating 22 lumbar trunk muscles was used to predict muscle contraction forces for the calibration tasks. Predicted forces were linearly correlated with the measured myoelectric activities for these tasks. The regression equations were then interpolated to estimate the muscle contraction forces from the myoelectric data during gait. Peak contraction forces for the iliocostalis muscles were calculated to be approximately 55 N per side, corresponding to total erector spinae peak contractions on the order of 140 N per side. For the other six muscles that were monitored, contraction forces were less than 15 N per side. This suggests that peak net reaction moments and peak spine compressions on the lumbar trunk during these walking tasks were on the order of 15 Nm and 1.2 times body weight, respectively.     

家兔腓肠肌在电刺激下力学行为的实验研究

目的 获得肌肉收缩力学特性与其电生理特性间的实验关系。方法 用肌电仪发出不同波宽、不同强度的脉冲电流，对家兔的胫神经进行刺激，记录其复合动作电位及收缩力。结果 得到了收缩力与各种肌电信号的实验关系曲线。结论收缩力与刺激电流之间呈正相关关系、与复合动作电位幅值(CAMP)之间呈线性关系，且收缩力与肌电积分值之间也呈较好的线性关系。     

术中诱发肌电图刺激值与椎弓根螺钉位置的关系研究

目的:探讨术中诱发肌电图刺激值与椎弓根螺钉至椎体后壁内侧之间距离的关系.方法:对33例闭合性腰椎骨折患者行后路椎弓根螺钉固定,并采用Endeavor术中神经监护仪对椎弓根螺钉进行电流刺激并记录刺激值,术后通过CT平扫及重建,确定每个椎弓根螺钉植入的位置并测量螺钉与椎体后壁内侧之间的距离.对诱发肌电图刺激值与相应椎弓根螺钉至椎体后壁内侧之间的距离进行线性回归分析,并建立回归方程.结果:33例患者共置入132枚椎弓根螺钉,其中5枚椎弓根螺钉置入失败,建立的回归预测方程为Y=5.22 +2.22X(t =5.479,P=0.003).结论:术中诱发肌电图监测对于最大限度地保证椎弓根螺钉准确置入、避免神经根损伤具有重要意义.利用建立的回归方程,术者可以在术中实时了解和评估椎弓根螺钉的位置,从而有效提高椎弓根置钉的成功率,减少神经损伤.     

Abdominal bracing changes lower quarter muscle activity but not reach distances during active forward reach on an unstable surface

ObjectiveThis study examined the effects of abdominal bracing maneuver (ABM) performance on stable and unstable surfaces on active forward reach (AFR) distance as a measure of trunk control, measuring changes in reach distance and muscle activation patterns.DesignSingle-group, repeated measures design.MethodsTwenty-eight subjects (mean age 25 ± 5.09 years) performed an AFR with and without ABM while on stable and unstable surfaces. Lower quarter muscle activity and forward reach distances were recorded.ResultsForward reach distances on the unstable surface were significantly decreased compared to the stable condition with and without ABM (p < .001). The surface-by-contraction interaction was significant for the tibialis anterior (TA) and gastrocnemius (GS). Significant main effects were found for internal oblique, external oblique, gluteus maximus, biceps femoris, TA, and GS, where muscle activity significantly increased during the ABM trials. The interaction between surface and contraction was significant for the TA and GS muscles. TA (p = .007) and GS (p < .001) activity increased with ABM on the unstable surface. TA activity increased with ABM on the stable surface (TA: p < .001).ConclusionReach distances decreased on the unstable surface, but ABM did not change reaching distance. Ankle muscle co-contraction occurred during ABM trials and posterior chain activity increased. These changes suggest ABM may be beneficial during forward reaching activities.     

Control strategies for active lower extremity prosthetics and orthotics: a review

Technological advancements have led to the development of numerous wearable robotic devices for the physical assistance and restoration of human locomotion. While many challenges remain with respect to the mechanical design of such devices, it is at least equally challenging and important to develop strategies to control them in concert with the intentions of the user.This work reviews the state-of-the-art techniques for controlling portable active lower limb prosthetic and orthotic (P/O) devices in the context of locomotive activities of daily living (ADL), and considers how these can be interfaced with the user’s sensory-motor control system. This review underscores the practical challenges and opportunities associated with P/O control, which can be used to accelerate future developments in this field. Furthermore, this work provides a classification scheme for the comparison of the various control strategies.As a novel contribution, a general framework for the control of portable gait-assistance devices is proposed. This framework accounts for the physical and informatic interactions between the controller, the user, the environment, and the mechanical device itself. Such a treatment of P/Os – not as independent devices, but as actors within an ecosystem – is suggested to be necessary to structure the next generation of intelligent and multifunctional controllers.Each element of the proposed framework is discussed with respect to the role that it plays in the assistance of locomotion, along with how its states can be sensed as inputs to the controller. The reviewed controllers are shown to fit within different levels of a hierarchical scheme, which loosely resembles the structure and functionality of the nominal human central nervous system (CNS). Active and passive safety mechanisms are considered to be central aspects underlying all of P/O design and control, and are shown to be critical for regulatory approval of such devices for real-world use.The works discussed herein provide evidence that, while we are getting ever closer, significant challenges still exist for the development of controllers for portable powered P/O devices that can seamlessly integrate with the user’s neuromusculoskeletal system and are practical for use in locomotive ADL.     

Comparison of immediate complete denture, tooth and implant-supported overdenture on vertical dimension and muscle activity

PURPOSE

To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture.

MATERIALS AND METHODS

Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables.

RESULTS

Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance.

CONCLUSION

Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis.     

Effect of natural mediotrusive contact on electromyographic activity of jaw and cervical muscles during chewing

Abstract

Objective. This study evaluated the effect of a natural mediotrusive contact on the electromyographic (EMG) activity of the anterior temporalis and sternocleidomastoid muscles during chewing in healthy subjects. Materials and methods. The study sample included two groups of 15 subjects each (Group 1: with natural mediotrusive contact; Group 2: without natural mediotrusive contact). Bilateral surface EMG activity was recorded on anterior temporalis and sternocleidomastoid muscles during unilateral chewing of a half cookie and unilateral chewing of a piece of apple. Anterior temporalis and sternocleidomastoid muscle activity was normalized against activity recorded during maximal voluntary clenching in intercuspal position and maximal intentional isometric head–neck rotation to each side, respectively. The partial and total asymmetry indexes were also calculated. Data were analyzed using Mann-Whitney, Wilcoxon and unpaired t-test. Results. EMG activity of anterior temporalis and sternocleidomastoid muscles showed no significant difference between the groups. EMG activity of anterior temporalis was similar between working and non-working sides during chewing in both groups. EMG activity of sternocleidomastoid muscle was higher in the working side than in the non-working side in Group 2 subjects. Asymmetry indexes were not significantly different between groups. Conclusions. The similar EMG pattern and asymmetry indexes observed suggest the predominance of central nervous control over peripheral inputs on anterior temporalis and sternocleidomastoid motor neuron pools.