scholarly journals Effects of Focal Vibration over Upper Limb Muscles on the Activation of Sensorimotor Cortex Network: An EEG Study

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Wei Li ◽  
Chong Li ◽  
Quan Xu ◽  
Linhong Ji
Keyword(s):  
Upper Limb ◽  
Sensorimotor Cortex ◽  
Biceps Brachii ◽  
Central Area ◽  
Therapeutic Effects ◽  
Relative Power ◽  
Alpha Band ◽  
Beta Band ◽  
Muscle Belly ◽  
Limb Muscles

Studying the therapeutic effects of focal vibration (FV) in neurorehabilitation is the focus of current research. However, it is still not fully understood how FV on upper limb muscles affects the sensorimotor cortex in healthy subjects. To explore this problem, this experiment was designed and conducted, in which FV was applied to the muscle belly of biceps brachii in the left arm. During the experiment, electroencephalography (EEG) was recorded in the following three phases: before FV, during FV, and two minutes after FV. During FV, a significant lower relative power at C3 and C4 electrodes and a significant higher connection strength between five channel pairs (Cz-FC1, Cz-C3, Cz-CP6, C4-FC6, and FC6-CP2) in the alpha band were observed compared to those before FV. After FV, the relative power at C4 in the beta band showed a significant increase compared to its value before FV. The changes of the relative power at C4 in the alpha band had a negative correlation with the relative power of the beta band during FV and with that after FV. The results showed that FV on upper limb muscles could activate the bilateral primary somatosensory cortex and strengthen functional connectivity of the ipsilateral central area (FC1, C3, and Cz) and contralateral central area (CP2, Cz, C4, FC6, and CP6). These results contribute to understanding the effect of FV over upper limb muscles on the brain cortical network.

Heteronymous reflex connections in human upper limb muscles in response to stretch of forearm muscles

2011 ◽  
Vol 106 (3) ◽  
pp. 1489-1499 ◽  
Author(s):  
Curtis D. Manning ◽  
Parveen Bawa
Keyword(s):  
Upper Limb ◽  
Biceps Brachii ◽  
Monosynaptic Reflex ◽  
Electromyographic Activity ◽  
Response Patterns ◽  
Triceps Brachii ◽  
Limb Muscles ◽  
Abductor Digiti Minimi ◽  
Human Upper Limb ◽  
Wrist Flexors

Torque motor produced stretch of upper limb muscles results in two distinct reflex peaks in the electromyographic activity. Whereas the short-latency reflex (SLR) response is mediated largely by the spinal monosynaptic reflex pathway, the longer-latency reflex (LLR) is suggested to involve a transcortical loop. For the SLRs, patterns of heteronymous monosynaptic Ia connections have been well-studied for a large number of muscles in the cat and in humans. For LLRs, information is available for perturbations to proximal joints, although the protocols for most of these studies did not focus on heteronymous connections. The main objective of the present study was to elicit both SLRs and LLRs in wrist flexors and extensors and to examine heteronymous connections from these muscles to elbow flexors (biceps brachii; BiBr) and extensors (triceps brachii; TriBr) and to selected distal muscles, including abductor pollicis longus (APL), first dorsal interosseous (FDI), abductor digiti minimi (ADM), and Thenars. The stretch of wrist flexors produced SLR and LLR peaks in APL, FDI, ADM, Thenars, and BiBr while simultaneously inducing inhibition of wrist extensors and TriBr. When wrist extensors were stretched, SLR and LLR peaks were observed in TriBr, whereas the primary wrist flexors, APL and BiBr, were inhibited; response patterns of FDI, ADM, and Thenars were less consistent. The main conclusions from the observed data are that: 1) as in the cat, afferents from wrist flexors and extensors make heteronymous connections with proximal and distal upper limb muscles; and 2) the strength of heteronymous connections is greater for LLRs than SLRs in the distal muscles, whereas the opposite is true for the proximal muscles. In the majority of observations, SLR and LLR excitatory peaks were observed together. However, on occasion, LLRs were observed without the SLR response in hand muscles when wrist extensors were stretched.

scholarly journals Cortical Oscillations in Cervical Dystonia and Dystonic Tremor

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Christopher W Hess ◽  
Bryan Gatto ◽  
Jae Woo Chung ◽  
Rachel L M Ho ◽  
Wei-en Wang ◽  
...  
Keyword(s):  
Upper Limb ◽  
Sensorimotor Cortex ◽  
Cervical Dystonia ◽  
General Pattern ◽  
Precision Grip ◽  
Head Movements ◽  
Therapeutic Interventions ◽  
Beta Band ◽  
Head Turning ◽  
Dystonic Tremor

Abstract Dystonia involves sustained or repetitive muscle contractions, affects different skeletal muscles, and may be associated with tremor. Few studies have investigated if cortical pathophysiology is impaired even when dystonic muscles are not directly engaged and during the presence of dystonic tremor (DT). Here, we recorded high-density electroencephalography and time-locked behavioral data in 2 cohorts of patients and controls during the performance of head movements, upper limb movements, and grip force. Patients with cervical dystonia had reduced movement-related desynchronization in the alpha and beta bands in the bilateral sensorimotor cortex during head turning movements, produced by dystonic muscles. Reduced desynchronization in the upper beta band in the ipsilateral motor and bilateral sensorimotor cortex was found during upper limb planar movements, produced by non-dystonic muscles. In a precision grip task, patients with DT had reduced movement-related desynchronization in the alpha and beta bands in the bilateral sensorimotor cortex. We observed a general pattern of abnormal sensorimotor cortical desynchronization that was present across the head and upper limb motor tasks, in patients with and without DT when compared with controls. Our findings suggest that abnormal cortical desynchronization is a general feature of dystonia that should be a target of pharmacological and other therapeutic interventions.

Cortical Control of Human Motoneuron Firing During Isometric Contraction

1997 ◽  
Vol 77 (6) ◽  
pp. 3401-3405 ◽  
Author(s):  
Stephan Salenius ◽  
Karin Portin ◽  
Matti Kajola ◽  
Riitta Salmelin ◽  
Riitta Hari
Keyword(s):  
Motor Cortex ◽  
Upper Limb ◽  
Isometric Contraction ◽  
Lower Limb ◽  
Biceps Brachii ◽  
Cortical Control ◽  
Lower Limb Muscles ◽  
Cortical Rhythms ◽  
Motor Unit Firing ◽  
Limb Muscles

Salenius, Stephan, Karin Portin, Matti Kajola, Riitta Salmelin, and Riitta Hari. Cortical control of human motoneuron firing during isometric contraction. J. Neurophysiol. 77: 3401–3405, 1997. We recorded whole scalp magnetoencephalographic (MEG) signals simultaneously with the surface electromyogram from upper and lower limb muscles of six healthy right-handed adults during voluntary isometric contraction. The 15- to 33-Hz MEG signals, originating from the anterior bank of the central sulcus, i.e., the primary motor cortex, were coherent with motor unit firing in all subjects and for all muscles. The coherent cortical rhythms originated in the hand motor area for upper limb muscles (1st dorsal interosseus, extensor indicis proprius, and biceps brachii) and close to the foot area for lower limb muscles (flexor hallucis brevis). The sites of origin corresponding to different upper limb muscles did not differ significantly. The cortical signals preceded motor unit firing by 12–53 ms. The lags were shortest for the biceps brachii and increased systematically with increasing corticomuscular distance. We suggest that the motor cortex drives the spinal motoneuronal pool during sustained contractions, with the observed cortical rhythmic activity influencing the timing of efferent commands. The cortical rhythms could be related to motor binding, but the rhythmic output may also serve to optimize motor cortex output during isometric contractions.

scholarly journals High-density surface electromyography signals during isometric contractions of elbow muscles of healthy humans

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Mónica Rojas-Martínez ◽  
Leidy Yanet Serna ◽  
Mislav Jordanic ◽  
Hamid Reza Marateb ◽  
Roberto Merletti ◽  
...  
Keyword(s):  
Upper Limb ◽  
Biceps Brachii ◽  
High Density ◽  
Isometric Contractions ◽  
Myoelectric Activity ◽  
Electrode Arrays ◽  
Triceps Brachii ◽  
Healthy Humans ◽  
Limb Muscles ◽  
Density Surface

AbstractThis paper presents a dataset of high-density surface EMG signals (HD-sEMG) designed to study patterns of sEMG spatial distribution over upper limb muscles during voluntary isometric contractions. Twelve healthy subjects performed four different isometric tasks at different effort levels associated with movements of the forearm. Three 2-D electrode arrays were used for recording the myoelectric activity from five upper limb muscles: biceps brachii, triceps brachii, anconeus, brachioradialis, and pronator teres. Technical validation comprised a signals quality assessment from outlier detection algorithms based on supervised and non-supervised classification methods. About 6% of the total number of signals were identified as “bad” channels demonstrating the high quality of the recordings. In addition, spatial and intensity features of HD-sEMG maps for identification of effort type and level, have been formulated in the framework of this database, demonstrating better performance than the traditional time-domain features. The presented database can be used for pattern recognition and MUAP identification among other uses.

scholarly journals Fatiguing effects of indirect vibration stimulation in upper limb muscles: pre, post and during isometric contractions superimposed on upper limb vibration

2019 ◽  
Vol 6 (10) ◽  
pp. 190019
Author(s):  
Amit N. Pujari ◽  
Richard D. Neilson ◽  
Marco Cardinale
Keyword(s):  
Upper Limb ◽  
Isometric Contraction ◽  
Exercise Intervention ◽  
Biceps Brachii ◽  
Whole Body ◽  
Emg Activity ◽  
Isometric Contractions ◽  
Fatigue Development ◽  
Limb Muscles ◽  
Fatiguing Contractions

Whole-body vibration and upper limb vibration (ULV) continue to gain popularity as exercise intervention for rehabilitation and sports applications. However, the fatiguing effects of indirect vibration stimulation are not yet fully understood. We investigated the effects of ULV stimulation superimposed on fatiguing isometric contractions using a purpose developed upper limb stimulation device. Thirteen healthy volunteers were exposed to both ULV superimposed to fatiguing isometric contractions (V) and isometric contractions alone Control (C). Both Vibration (V) and Control (C) exercises were performed at 80% of the maximum voluntary contractions. The stimulation used was 30 Hz frequency of 0.4 mm amplitude. Surface-electromyographic (EMG) activity of the Biceps Brachii, Triceps Brachii and Flexor Carpi Radialis were measured. EMG amplitude (EMGrms) and mean frequency (MEF) were computed to quantify muscle activity and fatigue levels. All muscles displayed significantly higher reduction in MEFs and a corresponding significant increase in EMGrms with the V than the Control, during fatiguing contractions ( p < 0.05). Post vibration, all muscles showed higher levels of MEFs after recovery compared to the control. Our results show that near-maximal isometric fatiguing contractions superimposed on vibration stimulation lead to a higher rate of fatigue development compared to the isometric contraction alone in the upper limb muscles. Results also show higher manifestation of mechanical fatigue post treatment with vibration compared to the control. Vibration superimposed on isometric contraction not only seems to alter the neuromuscular function during fatiguing efforts by inducing higher neuromuscular load but also post vibration treatment.

scholarly journals Force Sensation Induced by Electrical Stimulation of the Tendon of Biceps Muscle

2021 ◽  
Vol 11 (17) ◽  
pp. 8225
Author(s):  
Akifumi Takahashi ◽  
Hiroyuki Kajimoto
Keyword(s):  
Electrical Stimulation ◽  
Upper Limb ◽  
Biceps Brachii ◽  
Biceps Muscle ◽  
Muscle Belly ◽  
Force Perception ◽  
Muscle Stretching ◽  
Supporting Force ◽  
Wearable Interfaces ◽  
Stimulation Of

Many wearable interfaces have been proposed to present force to the upper limb and elbow joint. One way to achieve a compact wearable haptic interface is to use electrical stimulation, and we have suggested that transcutaneous electrical stimulation above the wrist tendon can produce force a sensation in the direction of the muscle stretching; however, it has not been investigated in detail whether the force sensation presented by the electrical stimulation of the tendon occurs in the upper limb joints. In this study, to investigate whether the force sensation is generated when applying electrical stimulation of the skin at the tendon or at the muscle belly of the biceps brachii muscle, we quantitatively evaluated the direction and amount of the force sensation under the aforementioned conditions. The results showed that the electrical stimulation of the tendon produced significant force sensation in the direction of elbow extension. On the other hand, in some participants, the electrical stimulation of the muscle belly worked as a supporting force, resulting in the sensation of weakened force perception. In general, we concluded that the sensation produced by muscle stimulation was different from that produced by stimulation of the tendon.

Muscle dependency of corticomuscular coherence in upper and lower limb muscles and training-related alterations in ballet dancers and weightlifters

2010 ◽  
Vol 109 (4) ◽  
pp. 1086-1095 ◽  
Author(s):  
Junichi Ushiyama ◽  
Yuji Takahashi ◽  
Junichi Ushiba
Keyword(s):  
Sensorimotor Cortex ◽  
Lower Limb ◽  
Tibialis Anterior ◽  
Biceps Brachii ◽  
Oscillatory Activity ◽  
Spinal Motoneurons ◽  
Ballet Dancers ◽  
Corticomuscular Coherence ◽  
Lower Limb Muscles ◽  
Limb Muscles

It has been well documented that the 15- to 35-Hz oscillatory activity of the sensorimotor cortex shows coherence with the muscle activity during weak to moderate steady contraction. To investigate the muscle dependency of the corticomuscular coherence and its training-related alterations, we quantified the coherence between electroencephalogram (EEG) from the sensorimotor cortex and rectified electromyogram (EMG) from five upper limb (first dorsal interosseous, flexor carpi radialis, extensor carpi radialis, biceps brachii, triceps brachii) and four lower limb muscles (soleus, tibialis anterior, biceps femoris, rectus femoris), while maintaining a constant force level at 30% of maximal voluntary contraction of each muscle, in 24 untrained, 12 skill-trained (ballet dancers), and 10 strength-trained (weightlifters) individuals. Data from untrained subjects demonstrated the muscle dependency of corticomuscular coherence. The magnitude of the EEG-EMG coherence was significantly greater in the distally located lower limb muscles, such as the soleus and tibialis anterior, than in the upper or other lower limb muscles in untrained subjects ( P < 0.05). These results imply that oscillatory coupling between the sensorimotor cortex and spinal motoneurons during steady contraction differs among muscles, according to the functional role of each muscle. In addition, the ballet dancers and weightlifters showed smaller EEG-EMG coherences than the untrained subjects, especially in the lower limb muscles ( P < 0.05). These results indicate that oscillatory interaction between the sensorimotor cortex and spinal motoneurons can be changed by long-term specialized use of the muscles and that this neural adaptation may lead to finer control of muscle force during steady contraction.

Effects of Leg Pedaling on Early Latency Cutaneous Reflexes in Upper Limb Muscles

2010 ◽  
Vol 104 (1) ◽  
pp. 210-217 ◽  
Author(s):  
Syusaku Sasada ◽  
Toshiki Tazoe ◽  
Tsuyoshi Nakajima ◽  
E. Paul Zehr ◽  
Tomoyoshi Komiyama
Keyword(s):  
Upper Limb ◽  
Biceps Brachii ◽  
Lower Limbs ◽  
Functional Coupling ◽  
Isometric Contractions ◽  
Rhythmic Movements ◽  
Discrete Movements ◽  
Cutaneous Reflex ◽  
Limb Muscles ◽  
Control Research

The functional coupling of neural circuits between the upper and lower limbs involving rhythmic movements is of interest to both motor control research and rehabilitation science. This coupling can be detected by examining the effect of remote rhythmic limb movement on the modulation of reflex amplitude in stationary limbs. The present study investigated the extent to which rhythmic leg pedaling modulates the amplitude of an early latency (peak 30–70 ms) cutaneous reflex (ELCR) in the upper limb muscles. Thirteen neurologically intact volunteers performed leg pedaling (60 or 90 rpm) while simultaneously contracting their arm muscles isometrically. Control experiments included isolated isometric contractions and discrete movements of the leg. ELCRs were evoked by stimulation of the superficial radial nerve with a train of rectangular pulses (three pulses at 333 Hz, intensity 2.0- to 2.5-fold perceptual threshold). Reflex amplitudes were significantly increased in the flexor carpi radialis and posterior deltoid and significantly decreased in the biceps brachii muscles during leg pedaling compared with that during stationary isometric contraction of the lower leg muscles. This effect was also sensitive to cadence. No significant modulation was seen during the isometric contractions or discrete movements of the leg. Additionally, there was no phase-dependent modulation of the ELCR. These findings suggest that activation of the rhythm generating system of the legs affects the excitability of the early latency cutaneous reflex pathways in the upper limbs.

scholarly journals Influence of upper limb training and analyzed muscles on estimate of physical activity during cereal grinding using saddle quern and rotary quern

2020 ◽  
Author(s):  
Michal Struška ◽  
Martin Hora ◽  
Thomas R. Rocek ◽  
Vladimír Sládek
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Biceps Brachii ◽  
Muscle Model ◽  
Electromyographic Activity ◽  
Replication Studies ◽  
Limb Loading ◽  
Limb Muscles ◽  
The Relationship ◽  
Muscle Models

AbstractExperimental grinding has been used to study the relationship between human humeral robusticity and cereal grinding in the early Holocene. However, such replication studies raise two questions regarding the robusticity of the results: whether female nonathletes used in previous research are sufficiently comparable to early agricultural females, and whether previous analysis of muscle activation of only four upper limb muscles is sufficient to capture the stress of cereal grinding on upper limb bones. We test the influence of both of these factors. Electromyographic activity of eight upper limb muscles was recorded during cereal grinding in an athletic sample of 10 female rowers and a nonathletic sample of 25 females and analyzed using both an eight- and four-muscle model. Athletes had lower activation than nonathletes in the majority of measured muscles, but most of these differences were non-significant. Furthermore, both athletes and nonathletes had lower muscle activation during saddle quern grinding than rotary quern grinding suggesting that the nonathletic sample can be used to model early agricultural females during saddle and rotary quern grinding.Similarly, in both eight- and four-muscle models, upper limb loading was lower during saddle quern grinding than during rotary quern grinding, suggesting that the upper limb muscles may be reduced to the previously used four-muscle model for evaluation of the upper limb loading during cereal grinding. Another implication of our measurements is to question the assumption that skeletal indicators of high involvement of the biceps brachii muscle can be interpreted as specifically indicative of saddle quern grinding.

scholarly journals Influence of upper limb training and analyzed muscles on estimate of physical activity during cereal grinding using saddle quern and rotary quern

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0243669
Author(s):  
Michal Struška ◽  
Martin Hora ◽  
Thomas R. Rocek ◽  
Vladimír Sládek
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Biceps Brachii ◽  
Muscle Model ◽  
Electromyographic Activity ◽  
Replication Studies ◽  
Limb Loading ◽  
Limb Muscles ◽  
The Relationship ◽  
Muscle Models

Experimental grinding has been used to study the relationship between human humeral robusticity and cereal grinding in the early Holocene. However, such replication studies raise two questions regarding the robusticity of the results: whether female nonathletes used in previous research are sufficiently comparable to early agricultural females, and whether previous analysis of muscle activation of only four upper limb muscles is sufficient to capture the stress of cereal grinding on upper limb bones. We test the influence of both of these factors. Electromyographic activity of eight upper limb muscles was recorded during cereal grinding in an athletic sample of 10 female rowers and in 25 female nonathletes and analyzed using both an eight- and four-muscle model. Athletes had lower activation than nonathletes in the majority of measured muscles, but except for posterior deltoid these differences were non-significant. Furthermore, both athletes and nonathletes had lower muscle activation during saddle quern grinding than rotary quern grinding suggesting that the nonathletes can be used to model early agricultural females during saddle and rotary quern grinding. Similarly, in both eight- and four-muscle models, upper limb loading was lower during saddle quern grinding than during rotary quern grinding, suggesting that the upper limb muscles may be reduced to the previously used four-muscle model for evaluation of the upper limb loading during cereal grinding. Another implication of our measurements is to question the assumption that skeletal indicators of high involvement of the biceps brachii muscle can be interpreted as specifically indicative of saddle quern grinding.

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