Generating-sensation and propagating-myoelectrical

The meridian phenomena are closely associated with the neuro-muscular function. Our experiments show that meridian phenomenon, acupoint stimulation-induced generating-sensations along meridians (GSM), does exist in some volunteers, and the subjects can describe the characteristics of the feelings and the route of GSM. Simultaneously, GSM is often accompanied with progressive myoelectric activity along the meridian which is able to be recorded objectively. Bra-chial plexus anesthesia and regional neuro-muscular block may arrest these responses while the neuro-muscular blocking agent may stop neuromuscular transmission at the motor end-plate rather than check GSM. The facts reveal that GSM probably depends on muscular activity and is involved in the secondary neuro-muscular excitation propagating along the longitudinal axis of muscles. These findings suggest that the myoelectric activities constitute the foundation of secondarily generating-sensation propagating along the longitudinal orientation of limbs     

Neurobiological mechanisms of the meridian and the propagation of needle feeling along the meridian pathway

The present experiments attempt to find the meridian phenomenon and how the needle feeling propagates along the given meridian channels. The neurobiological mechanisms of the meridian were studied with neuroelectrical recording from the motor neurons and CB-HRP retrograde histochemistry technique in both rats and cats. The results demonstrated that most, but not all, of alpha motor neurons supplying a muscle group of a given meridian were selectively activated by afferent inputs originating not only from homonymous or heterogeneous, but synergistic muscle, but also from the skin nerve overlying the muscle group of the homonymous meridian. However, the afferent inputs from the heterogeneous meridian have very weak or no effect. On the other hand, the labeled motor neurons supplying a given meridian muscles form a discrete longitudinal column with a definite bound in the lateral ventral horn. There are oriented dendro-dendristes projections between the labeled motor neurons.The characteristics of both sel     

Optically pumped magnetometers disclose magnetic field components of the muscular action potential

AimAiming at analysing the signal conduction in muscular fibres, the spatio-temporal dynamics of the magnetic field generated by the propagating muscle action potential (MAP) is studied.MethodIn this prospective, proof of principle study, the magnetic activity of the intrinsic foot muscle after electric stimulation of the tibial nerve was measured using optically pumped magnetometers (OPMs). A classical biophysical electric dipole model of the propagating MAP was implemented to model the source of the data. In order to account for radial currents of the muscular tubules system, a magnetic dipole oriented along the direction of the muscle was added.ResultsThe signal profile generated by the activity of the intrinsic foot muscles was measured by four OPM devices. Three OPM sensors captured the spatio-temporal magnetic field pattern of the longitudinal intrinsic foot muscles. Changes of the activation pattern reflected the propagating muscular action potential along the muscle. A combined electric and magnetic dipole model could explain the recorded magnetic activity.InterpretationOPM devices allow for a new, non-invasive way to study MAP patterns. Since magnetic fields are less altered by the tissue surrounding the dipole source compared to electric activity, a precise analysis of the spatial characteristics and temporal dynamics of the MAP is possible. The classic electric dipole model explains major but not all aspects of the magnetic field. The field has longitudinal components generated by intrinsic structures of the muscle fibre. By understanding these magnetic components, new methods could be developed to analyse the muscular signal transduction pathway in greater detail. The approach has the potential to become a promising diagnostic tool in peripheral neurological motor impairments.     

经络腧穴的光学特性研究进展

现已成熟并仍有巨大潜力的光子学技术与热、电、磁等一起成为研究经络腧穴的热门手段,经络腧穴光学特性的探索不仅为其存在提供了客观依据,而且为其实际应用提供了生物物理学依据。总结目前用于经络腧穴研究的光学检测方法原理,重点综述了经络腧穴的超微弱发光、经脉红外辐射路线的客观显示、腧穴的红外辐射光谱及循经激光传输等方面的最新研究进展,以期对光子学手段在经络腧穴的研究上有一个全面的认识。     

Quadriceps and hamstrings prelanding myoelectric activity during landing from different heights among male and female athletes

ACL tear is a major concern among athletes, coaches and sports scientists. More than taking the athlete away from training and competition, ACL tear is a risk factor for early-onset of knee osteoarthritis, and, therefore addressing strategies to avoid such injury is pertinent not only for competitive athletes, but for all physically active subjects. Imbalances in the prelanding myoelectric activity of the hamstrings and quadriceps muscles have been linked to ACL injuries. We investigated the effect of landing from different heights on prelanding myoelectric activity of the hamstrings and quadriceps muscles in recreational athletes. Thirty recreational athletes (15 male and 15 female) performed three bilateral drop jumps from two different heights; 20 cm and 40 cm while myoelectric activity of the vastus medialis, rectus femoris, biceps femoris and medial hamstrings were collected. When increasing the height of drop landing tasks prelanding normalized myoelectric activity of the quadriceps was increased by 15–20% but no significant changes were found for the hamstrings. Female athletes exhibited higher activity of the medial hamstrings compared to their male counterparts. We concluded that increasing the height of drop landing tasks is associated with increased myoelectric activity of the quadriceps but not the hamstrings in recreational athletes. These differences in muscle activity may be related to increased risk for ACL injury when the height is increased. Female athletes demonstrated higher recruitment of the medial hamstrings.     

Mechanism of relation among heart meridian,referred cardiac pain and heart

It has been demonstrated that an important clinical phenomenon often associated with visceral diseases is the referred pain to somatic structures, especially to the body area of homo-segmental innervation. It is interesting that the somatic foci of cardiac referred pain were often and mainly distributed along the heart meridian (HM), whereas the acupoints of HM have been applied to treat cardiac disease since ancient times. The purpose of this study was to investigate the neural relationship between the cardiac referred pain and the heart meridian. Fluorescent triple-labeling was injected into the pericardium, some acupoints of HM and lung meridian (LM, for control). The responses of the left cardiac sympathetic nerve and of the EMG in left HM and LM were electrophysiologically studied, when the electrical stimuli were applied to the acupoints of left HM and to the left cardiac sympathetic nerve. More double-labeled neurons in HM-heart, not in LM-heart, were observed in the ipsilateral dorsal root ganglia of the spinal segments C8-T3. Electric stimulation of the acupoints of left HM was able to elicit more responses of left cardiac sympathetic nerve than that of the LM-acupoints. Electric stimulation of the left cardiac sympathetic nerve resulted in stronger activities of EMG-response in the acupoints of left HM than in LM-acupoints. We conclude that double-labeling study has provided direct evidence for the existence of dichotomizing afferent fibers that supply both the pericardium and HM. Electrophysiological results show that HM is more closely related functionally to heart. These findings provide a possible morphological and physiological explanation for the referred cardiac pain and HM-heart interrelation.     

Myoelectric stimulation on peroneal muscles resists simulated ankle sprain motion

The inadequate reaction time of the peroneal muscles in response to an incorrect foot contact event has been proposed as one of the etiological factors contributing to ankle joint inversion injury. Thus, the current study aimed to investigate the efficacy of a myoelectric stimulation applied to the peroneal muscles in the prevention of a simulated ankle inversion trauma. Ten healthy male subjects performed simulated inversion and supination tests on a pair of mechanical sprain simulators. An electrical signal was delivered to the peroneal muscles of the subjects through a pair of electrode pads. The start of the stimulus was synchronized with the drop of the sprain simulator's platform. In order to determine the maximum delay time which the stimulus could still resist the simulated ankle sprain motion, different delay time were test (0, 5, 10, and 15ms). Together with the control trial (no stimulus), there were 5 testing conditions for both simulated inversion and supination test. The effect was quantified by the drop in maximum ankle tilting angle and angular velocity, as determined by a motion analysis system with a standard laboratory procedure. Results showed that the myoelectric stimulation was effective in all conditions except the one with myoelectric stimulus delayed for 15ms in simulated supination test. It is concluded that myoelectric stimulation on peroneal muscles could resist an ankle spraining motion.     

Mechanism of relation among heart meridian, referred cardiac pain and heart

It has been demonstrated that an important clinical phenomenon often associated with visceral diseases is the referred pain to somatic structures, especially to the body area of homo-segmental innervation. It is interesting that the somatic foci of cardiac referred pain were often and mainly distributed along the heart meridian (HM), whereas the acupoints of HM have been applied to treat cardiac disease since ancient times. The purpose of this study was to investigate the neural relationship between the cardiac referred pain and the heart meridian. Fluorescent triple-labeling was injected into the pericardium, some acupoints of HM and lung meridian (LM, for control). The responses of the left cardiac sympathetic nerve and of the EMG in left HM and LM were electrophysiologically studied, when the electrical stimuli were applied to the acupoints of left HM and to the left cardiac sympathetic nerve. More double-labeled neurons in HM-heart, not in LM-heart, were observed in the ipsilateral dorsal root gangli     

Changes in colonic myoelectric spiking activity during stimulation by bisacodyl

The purpose of this study was to determine some relationships between colonic myoelectric spiking activity and intraluminal propulsion when colonic peristalsis was stimulated by bisacodyl. Myoelectric recordings were obtained in 12 subjects by means of a 50 cm long Silastic tube equipped with four bipolar electrodes fixed at 10-cm intervals. The tube was introduced into the left colon by flexible sigmoidoscopy and the electrodes were located at 50, 40, 30, and 20 cm from the anal verge. A small polyethylene catheter opening at the proximal end of the Silastic tube was used for introducing the laxative into the colon. One hour recording sessions were obtained before and after bisacodyl administration (5 mL of 0.4% solution). The control tracings showed that colonic spiking activity was made of rhythmic stationary bursts that occurred at only one electrode site and of sporadic bursts that were either propagating over the whole colonic segment or nonpropagating. Administration of bisacodyl was followed by complete suppression of the rhythmic stationary activity; a considerable increase in the sporadic spiking activity, propagating as well as nonpropagating; the occurrence of abdominal cramps and urgency to defecate, both associated with the propagating sporadic spike bursts. It is concluded that colonic propulsion induced by bisacodyl may be dependent upon the production of the sporadic bursts, particularly the propagating ones, while the rhythmic stationary bursts do not seem to play a significant role in colonic transit.     

中医经络的光子学研究

在中医经络现代研究的基础上,探讨光子学在经脉循行路线的客观检测,循经感传现象的发生及其实质意义,经络腧穴诊断的客观化以及腧穴双向良性调节作用等研究领域的具体应用.指出中医经络的光子学研究有望借助光子学的学科优势,从科学的角度对我国经络学说进行诠释和量化,为经脉腧穴的光学特性提供重要的实验依据,并有望找到一种非侵人性、无...     

Effect of cervical spine position on upper limb myoelectric activity during pre-manipulative stretch for Mills manipulation: a new model, relations to peripheral nerve biomechanics and specificity of Mills manipulation

Objectives(A) Describe a new method of investigation of the possible muscular effects of the commonly practiced Mills manipulation for lateral elbow pain (epicondylalgia), (B) ascertain if myoelectric activity is influenced during the pre-manipulative stretch for Mills manipulation, (C) establish whether muscle responses are influenced by ipsilateral lateral flexion of the cervical spine which reduces mechanical tension in the peripheral nerves of the upper limb.SampleEight asymptomatic subjects were tested bilaterally (N = 16).MethodsMyoelectric measurements – EMG signals were recorded with a 16 channel pocket EMG patient unit and processed off-line. Measurement of joint positions-three CCD adjustable cameras sensitive to 10 mm reflective passive markers applied at specific locations on the subjects’ bodies were used to reconstruct and verify accuracy of body movements and were correlated with EMG recordings.ResultsCompared with the standard (anatomical) position of the cervical spine in which Mills manipulation is typically performed, cervical spine ipsilateral lateral flexion produced significantly reduced activity in muscles that restrain the manipulation movement (elbow extension), namely biceps brachii (P = 0.018) and brachioradialis (P = 0.000). The affected muscles may therefore produce protective effects during the manipulation.ConclusionsChanges in myoelectric activity were in a pattern that suggests that muscle and neural mechanisms may be an integral part of the Mills manipulation. Cervical spine ipsilateral lateral flexion may be used to reduce mechanical stresses in the peripheral nerves and extraneous muscle activity, making Mills’ manipulation potentially safer and more specific.     

The amplitude distribution of surface EMG in static and intermittent static muscular performance.

A measure of the variation of load on individual muscles or parts of muscles may be obtained by estimating the amplitude probability distribution function (APDF) of the myoelectric signal. In a study of elbow flexor muscular performance in static and intermittent static low level muscular contractions, the APDF was computed from the surface EMG obtained from the belly of the brachial biceps muscle. The APDF was also computed from the simultaneously recorded force signal. The APDF of the myoelectric signal and of the force signal were similar, indicating that the APDF of the myoelectric signal closely reflects the muscular load in non-fatiguing muscular contractions. The effect of the time constant in lowpass filtering when processing the surface EMG-signals was also studied. A suitable time constant appears to be in the range of 50-100 ms.     

How does morphine work on colonic motility? An electromyographic study in the human left and sigmoid colon

The effect of morphine on colonic motility was investigated by recording the colonic myoelectric spiking activity by means of a 50 cm long silastic tube equipped with 4 bipolar AgAgCl ring electrodes fixed at 10 cm intervals that was introduced into the left colon in 8 healthy subjects by flexible sigmoidoscopy. Tracings were obtained for 1 hour in the fasting state and for another 1 hour after i.m. injection of morphine sulphate 0.15 mg/kg. The different types of spike bursts were compared before and after morphine injection. The control tracings showed that the spiking activity of the colon was made of 2 types: 1)- Rhythmic Stationary Spike Bursts (RSB), that were seen at only one electrode site; 2)- Sporadic Bursts, that were either propagating over all 4 electrodes (SPB) or non propagating (SNPB). Injection of morphine was followed by 1)- a considerable increase in the number of RSB from 107 +/- 43 bursts/hour (mean +/- SEM) to 491 +/- 23 bursts/hour; 2)- the complete disappearance of the SPB dropping from 7.3 +/- 2.0 bursts/hour to 0.3 +/- 0.2 bursts/hour; 3)- no significant change in SNPB (from 52 +/- 4 bursts/hour to 57 +/- 5 bursts/hour). These results indicate that 1)- stimulation of colonic smooth muscle activity by morphine seems to result from an increase in the number of rhythmic stationary bursts; 2)- however inhibition of colonic transit may be related to the decrease in the number of sporadic propagating bursts.     

Structure of the neuromuscular spindles in the tongue of human fetuses

The dynamics in development of some components--of the neuromuscular spindles in the human fetus and newborn tongues have been studied by means of certain general and neurohistological methods with elements of morphometry. During the whole prenatal period of the human life, there is a certain synchronism in the development of the lingual proper muscles and the neuro-muscular spindles. Certain integration in the development of the neuro-muscular spindles is observed in 4-6-month-old fetuses; in 8-9-month-old fetuses and in newborns it is substituted for heterochronicity. By the time of birth, the muscle spindle contractile elements are supplied with a more differentiated efferent innervation. The latter actively effects the morphological state of the intrafusal muscle fibers and forms a base for functional activity of the tongue.     

NO在胆道加压引起的反射活动中的作用

向胆道加压至 4kPa ,可同时引起血压降低和Oddi括约肌 (SO)肌电活动减弱或消失 ,这总称为胆道加压反射 ,其中前者称为胆道 血压反射 ,后者称为胆道 SO反射。本实验应用 3 2只家兔观察一氧化氮 (NO)对胆道加压反射活动的影响。在静脉滴注去甲肾上腺素 4 μg/(kg·min)引起血压升高和SO肌电振幅增大的基础上 ,再行胆道加压至 4kPa ,仍同时引起血压降低和Oddi括约肌 (SO)肌电活动减弱 ;而在静脉注射NO合酶抑制剂NG 硝基 L 精氨酸 (L NNA) 10mg/kg引起血压升高和SO肌电振幅增大的基础上 ,再行胆道加压至 4kPa,全部动物胆道 血压反射受到完全抑制 ,即未出现血压降低反应 ;少数 ( 3 /8)动物胆道 SO反射受到完全抑制 ,多数 ( 5 /8)动物该反射受到明显抑制 (P <0 0 1)。向SO局部灌注L NNA ,只引起SO肌电振幅增大而不影响血压 ,在此基础上行胆道加压 ,对胆道 SO反射的影响与全身用药相似 ,对胆道 血压反射却无影响。这提示 ,这两种反射活动是相对独立的 ,是经不同传出途径和效应器实现的 ;且这两种反射都主要是通过NO介导的     

Three-Dimensional Muscle Architecture and Comprehensive Dynamic Properties of Rabbit Gastrocnemius,Plantaris and Soleus: Input for Simulation Studies

The vastly increasing number of neuro-muscular simulation studies (with increasing numbers of muscles used per simulation) is in sharp contrast to a narrow database of necessary muscle parameters. Simulation results depend heavily on rough parameter estimates often obtained by scaling of one muscle parameter set. However, in vivo muscles differ in their individual properties and architecture. Here we provide a comprehensive dataset of dynamic (n = 6 per muscle) and geometric (three-dimensional architecture, n = 3 per muscle) muscle properties of the rabbit calf muscles gastrocnemius, plantaris, and soleus. For completeness we provide the dynamic muscle properties for further important shank muscles (flexor digitorum longus, extensor digitorum longus, and tibialis anterior; n = 1 per muscle). Maximum shortening velocity (normalized to optimal fiber length) of the gastrocnemius is about twice that of soleus, while plantaris showed an intermediate value. The force-velocity relation is similar for gastrocnemius and plantaris but is much more bent for the soleus. Although the muscles vary greatly in their three-dimensional architecture their mean pennation angle and normalized force-length relationships are almost similar. Forces of the muscles were enhanced in the isometric phase following stretching and were depressed following shortening compared to the corresponding isometric forces. While the enhancement was independent of the ramp velocity, the depression was inversely related to the ramp velocity. The lowest effect strength for soleus supports the idea that these effects adapt to muscle function. The careful acquisition of typical dynamical parameters (e.g. force-length and force-velocity relations, force elongation relations of passive components), enhancement and depression effects, and 3D muscle architecture of calf muscles provides valuable comprehensive datasets for e.g. simulations with neuro-muscular models, development of more realistic muscle models, or simulation of muscle packages.     

Metabolic variability within individual fibres of the cat tibialis posterior and diaphragm muscles

Summary Variance in succinate dehydrogenase activity along the transverse and longitudinal axes of fibres from the cat tibialis posterior and diaphragm muscles was determined in order to estimate the three-dimensional distribution of mitochondria within single fibres. The variance (coefficient of variation) in succinate dehydrogenase activity along the transverse fibre axis was greatest in type IIB fibres from both muscles. Intracellular compartmentalization (i.e. subsarcolemmal vs central core differences in succinate dehydrogenase activity) was observed only in type II fibres from the tibialis posterior; the succinate dehydrogenase activity of the subsarcolemmal region was significantly greater than that of the central core. The extent of succinate dehydrogenase variance along the longitudinal fibre axis was dependent on the total length of the fibre segment analyzed, the muscle, and fibre type. The coefficient variation for short fibre segments, i.e. 40 m, was significantly lower than that for much longer fibre segments (840 m). Significant differences in the coefficient variation for 840 m fibre segments were observed between the diaphragm and tibialis posterior muscles. The longitudinal variance in succinate dehydrogenase activity was higher in diaphragm muscle fibres. The succinate dehydrogenase variance along the longitudinal axis of type II fibres was significantly greater than that of the type I fibre population. These results indicate that mitochondria are heterogeneously distributed within muscle fibres. Possible functional implications of such intrafibre metabolic variance are discussed.     

Development and embryonic pattern of body wall musculature in the crassiclitellate Eisenia andrei (Annelida,Clitellata)

During early development of Eisenia andrei (Crassiclitellata), a loose arrangement of primary circular and longitudinal muscles encloses the whole embryo. Circular muscles differentiate in an anterior–posterior progression creating a segmental pattern. Primary circular muscles emerge at the segmental borders while later in development the central part of each segment is filled with circular strands. Longitudinal muscles develop in an anterio‐posterior manner as well, but by continuous lengthening. Muscle growth is not restricted by segmental boundaries. The development begins with one pair of prominent longitudinal muscles differentiating ventrally along the right and the left germ band. These first muscles provide a guiding structure for the parallel organization of the afterwards differentiating longitudinal musculature. Additional primary longitudinal muscles emerge and form, together with the initial circular muscles, the primary muscle grid of the embryo. During the following development, secondary longitudinal muscle strands develop and integrate themselves into the primary grid. Meanwhile the primary circular muscles split into thin strands in a ventral to dorsal progression. Thus, a fine structured mesh of circular and longitudinal muscles is generated. Compared to other “Oligochaeta”, embryonic muscle patterns in E. andrei are adapted to the development of a lecithotrophic embryo. Nevertheless, two general characteristics of annelid muscle development become evident. The first is the segmental development of the circular muscles from a set of initial muscles situated at the segment borders. Second, there is a continuous development of primary longitudinal muscles starting at the anterior pole. At least one pair of main primary longitudinal strands is characteristic in Annelida. The space between all primary strands is filled with secondary longitudinal strands during further development. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.     

A comparison of surface and fine wire EMG recordings of gluteus medius during selected maximum isometric voluntary contractions of the hip

Electromyographic (EMG) studies into gluteus medius (GMed) typically involve surface EMG electrodes. Previous comparisons of surface and fine wire electrode recordings in other muscles during high load isometric tasks suggest that recordings between electrodes are comparable when the muscle is contracting at a high intensity, however, surface electrodes record additional activity when the muscle is contracting at a low intensity. The purpose of this study was to compare surface and fine wire recordings of GMed at high and low intensities of muscle contractions, under high load conditions (maximum voluntary isometric contractions, MVICs). Mann–Whitney U tests compared median electrode recordings during three MVIC hip actions; abduction, internal rotation and external rotation, in nine healthy adults. There were no significant differences between electrode recordings in positions that evoked a high intensity contraction (internal rotation and abduction, fine wire activity >77% MVIC; effect size, ES < 0.42; p > 0.277). During external rotation, the intensity of muscle activity was low (4.2% MVIC), and surface electrodes recorded additional myoelectric activity (ES = 0.67, p = 0.002). At low levels of muscle activity during high load isometric tasks, the use of surface electrodes may result in additional myoelectric recordings of GMed, potentially reflective of cross-talk from surrounding muscles.     

Kinesiological research: The use of surface electromyography for assessing the effects of spinal manipulation

Decreasing an elevated muscle tone is an often cited benefit of spinal manipulation. Spinal manipulation is theorized to disrupt an assumed pain-spasm-pain cycle that sufferers of low back pain may be experiencing. The current research has mostly investigated the short term influence of a single spinal manipulation on paraspinal muscle activity either at rest (e.g. standing or prone) or during simple movements (e.g. forward bend). The higher quality experiments to date have typically reported both reductions in muscle activity during lying prone or during the fully flexed position of forward bend. The only study measuring the long term influence of spinal manipulation has failed to document any change in muscle activity as measured with surface electromyography. Both manually delivered manipulations and manipulations delivered via a mechanical adjusting device have been associated with changes in muscle activation. Changes in muscle activity at muscles distant from the spinal joints manipulated (e.g. muscles in the upper limbs) have been documented following a single spinal manipulation however rather than the typical reduction in muscle activity an increase in resting activation has been reported. The state of muscle dysfunction (e.g. palpably tender or subjectively taut) may be a factor in achieving a myoelectric response to spinal manipulation. Currently, the clinical significance of short term changes in electromyographic amplitude following manipulation is unknown.