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

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.

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Mónica Rojas-Martínez ◽  
Leidy Yanet Serna ◽  
Mislav Jordanic ◽  
Hamid Reza Marateb ◽  
Roberto Merletti ◽  
...  

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.


2014 ◽  
Vol 8 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Hiroyuki Inoue ◽  
◽  
Toshiro Noritsugu

This paper proposes an upper-limb power-assist machine that is driven by a single actuator to reduce its weight and cost. The assist machine is intended for supporting shoulder and elbow movements during work in the field of viticulture. It consists of an arm part, a mounting part, and a drive part, the last of which contains an actuator and a worm gear. The arm part is equipped with a parallel link mechanism. In order to realize natural upper-limb motion, the length of the arm part is designed on the basis of human upper-limb motion. The assist machine is controlled by user intention through the use of bending sensors attached to the input device. The assistance effectiveness of the proposed assist machine is verified experimentally by measuring the EMG signals of the deltoid, biceps brachii, and triceps brachii muscles.


2020 ◽  
Author(s):  
Michal Struška ◽  
Martin Hora ◽  
Thomas R. Rocek ◽  
Vladimír Sládek

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.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0243669
Author(s):  
Michal Struška ◽  
Martin Hora ◽  
Thomas R. Rocek ◽  
Vladimír Sládek

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.


1981 ◽  
Vol 94 (1) ◽  
pp. 15-42 ◽  
Author(s):  
G. E. Goslow ◽  
H. J. Seeherman ◽  
C. R. Taylor ◽  
M. N. McCutchin ◽  
N. C. Heglund

Electrical activity and length changes of 11 muscles of the fore- and hind- limbs of dogs walking, running, and galloping on a treadmill, were measured as a function of forward speed and gait. Our purpose was to find out whether the activity patterns of the major limb muscles were consistent with the two mechanisms proposed for storage and recovery of energy within a stride: a ‘pendulum-like’ mechanism during a walk, and a ‘spring-like’ mechanism during a run. In the stance phase of the walking dog, we found that the supraspinatus, long head of the triceps brachii, biceps brachii, vastus lateralis, and gastrocnemius underwent only minor length changes during a relatively long portion of their activity, Thus, a major part of their activity during the walk seems consistent with a role in stabilization of the joints as the dog ‘pole-vaulted’ over its limbs (and thereby conserved energy). In the stance phase of trotting and/or galloping dogs, we found that the supraspinatus, lateral head of the triceps, vastus lateralis, and gastrocnemius were active while being stretched prior to shortening (as would be required for elastic storage of energy), and that this type of activity increased with increasing speed. We also found muscular activity in the select limb flexors that was consistent with storage of kinetic energy at the end of the swing phase and recovery during the propulsive stroke. This activity pattern was apparent in the latissimus dorsi during a walk and trot, and in the biceps femoris during a trot and gallop. We conclude that, during locomotion, a significant fraction of the electrical activity of a number of limbs muscles occurs while they undergo little or no length change or are being stretched prior to shortening and that these types of activities occur in a manner that would enable the operation of pendulum-like and spring-like mechanisms for conserving energy within a stride. Therefore these forms of muscular activity, in addition to the more familiar activity associated with muscle shortening, should be considered to be important during locomotion.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Wei Li ◽  
Chong Li ◽  
Quan Xu ◽  
Linhong Ji

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.


2015 ◽  
Vol 11 (2) ◽  
pp. 65-74 ◽  
Author(s):  
K.L. Cullen ◽  
J.P. Dickey ◽  
S.H.M. Brown ◽  
S.G. Nykamp ◽  
L.R. Bent ◽  
...  

This study investigated the feasibility of obtaining ultrasound-guided intramuscular fine-wire electromyographic (fEMG) recordings from four canine shoulder muscles during highly dynamic activities. Four cadaveric canines were utilised to confirm the appropriate anatomical landmarks and the use of real time ultrasound guidance for electrode placement for four shoulder muscles: Biceps Brachii (BB), Supraspinatus (SP), Infraspinatus (IF), and Triceps Brachii – Long Head (TBLH). Electromyographic activity of the left BB, S P, IF, and TBLH was then recorded in two research dogs while walking and trotting to refine the data collection procedures. Finally, the full experimental protocol was piloted with two client-owned, specially-trained agility dogs, confirming the feasibility of collecting fEMG recordings while performing dynamic, highly-specific agility-related tasks and verifying our EMG amplitude normalisation protocol to enable comparisons across muscles and performance tasks. We present specific guidelines regarding the placement of fEMG electrodes and data collection/normalisation procedures to enable investigations of muscle activation during dynamic activities.


2011 ◽  
Vol 23 (01) ◽  
pp. 75-82 ◽  
Author(s):  
Yu-Lin Ning ◽  
Jia-Da Li ◽  
Wei-Ching Lo ◽  
Chih-Hung Huang ◽  
Chu-Fen Chang ◽  
...  

Adequate pattern and consistency of the muscle recruitment is essential to symbolize the destruction of the opponent with high movement velocities and precise targeting of the opponent's head and body during a karate jab. The purpose of this study was to evaluate the reaction time (RT), motor time (MT), and total response time (TRT), as well as their correlation during a karate jab, and to investigate the recruitment pattern and consistency of muscles during motor time. As many as 14 professional karate athletes (age: 23.67 ± 2.64 years; height: 174.57 ± 7.13 cm; and weight: 72.75 ± 10.65 kg) participated in the current study. Each subject was instructed to pose in combat stance first and then to use their left hand to jab at an instrumented kicking target as soon as they saw the start signal. Surface electromyograms (EMGs) were recorded from 16 muscles, namely the pronator teres, biceps brachii, triceps brachii, and deltoid of the left upper limb, right erector spinae, left rectus abdominis, and gluteus maximus, rectus femoris, biceps femoris, tibialis anterior, and medial gastrocnemius of the right and left lower limbs. Start and stop signals from the instrumented target were also recorded synchronously to obtain the TRT. Significant correlation between MT and TRT indicated that MT was a key determinant for the TRT of the jab. When performing a karate jab, the karate athletes initiated the movement with postural adjustments of the legs and trunk prior to the onset of the voluntary jab by the upper limb, and with a proximal-to-distal sequence of muscle activation in the left arm. Good consistencies of muscle recruitment of the trunk, left arm, and leg, and cocontraction of the left triceps and biceps brachii also indicated a well-controlled jab by the left arm. These results provide important information on the patterns and the consistencies of the muscle recruitment for coaching a karate jab, which should be helpful for a better understanding of the motor control strategies of a karate jab and for developing a suitable training protocol.


2015 ◽  
Vol 19 (4) ◽  
pp. 597-603 ◽  
Author(s):  
Áurea Maria de Ponte ◽  
Elaine Caldeira de Oliveira Guirro ◽  
Ariane Hidalgo Mansano Pletsch ◽  
Almir Vieira Dibai-Filho ◽  
Hugo Evangelista Brandino ◽  
...  

1997 ◽  
Vol 77 (6) ◽  
pp. 3401-3405 ◽  
Author(s):  
Stephan Salenius ◽  
Karin Portin ◽  
Matti Kajola ◽  
Riitta Salmelin ◽  
Riitta Hari

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.


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