The forearm positioning changes electromyographic activity of upper limb muscles and handgrip strength in the task of pushing a load cart

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.

Download Full-text

Immediate electromyographic changes of the upper limb muscles following cervical manipulation in a patient with essential tremor: a case report

ConScientiae Saúde ◽

10.5585/conssaude.v14n1.5297 ◽

2015 ◽

Vol 14 (1) ◽

pp. 141-146

Author(s):

Emanuele Carvalho ◽

Camila Silva ◽

Ana Paula Santos ◽

Fábio Luiz Martins ◽

Michelle Almeida Barbosa ◽

...

Keyword(s):

Case Report ◽

Essential Tremor ◽

Upper Limb ◽

Surface Electromyography ◽

Previous Treatment ◽

Electromyographic Activity ◽

Median Frequency ◽

Limb Muscles ◽

Before And After ◽

Cervical Manipulation

Introduction and Objective: The purpose of this case report is to evaluate upper limb muscle electric behavior by surface electromyography before and after cervical manipulation in a patient with essential tremor. Methods: In 2009, essential tremor was diagnosed by a neurologist in a 25-year-old woman. Previous treatment included Paroxetine for a number of months, without alteration of her symptoms. The patient was assessed by surface electromyography of the upper limb muscles (flexor and extensor of the wrist, long heads of biceps and triceps) before and after being subjected to high-velocity, low-amplitude spinal manipulation to her mid cervical spine (C3-C4 level, 1 manipulation/side). Results: There was an increase of the median frequency rate and a decrease of the electrical activity of these muscles. Conclusion: This case study showed the cervical manipulation technique acutely modifying the electromyographic activity, increasing the median frequency, and decreasing the muscle recruitment of the upper limb. It suggests improved motor control during the tasks.

Download Full-text

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

10.1101/2020.11.26.399600 ◽

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.

Download Full-text

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

PLoS ONE ◽

10.1371/journal.pone.0243669 ◽

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.

Download Full-text

Reflex Responses in Upper Limb Muscles to Cutaneous Stimuli

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/s0317167100048174 ◽

1993 ◽

Vol 20 (04) ◽

pp. 271-278 ◽

Cited By ~ 30

Author(s):

R. Chen

Keyword(s):

Stimulus Intensity ◽

Upper Limb ◽

Healthy Subjects ◽

Voluntary Contraction ◽

Cutaneous Reflexes ◽

Focal Lesions ◽

Normal Ranges ◽

Conduction Velocities ◽

Limb Muscles ◽

Biphasic Responses

ABSTRACT:Cutaneous reflexes in the upper limb were elicited by stimulating digital nerves and recorded by averaging rectified EMG from proximal and distal upper limb muscles during voluntary contraction. Distal muscles often showed a triphasic response: an inhibition with onset about 50 ms (Il) followed by a facilitation with onset about 60 ms (E2) followed by another inhibition with onset about 80 ms (12). Proximal muscles generally showed biphasic responses beginning with facilitation or inhibition with onset at about 40 ms. Normal ranges for the amplitude of these components were established from recordings on 22 arms of 11 healthy subjects. An attempt was made to determine the alterent fibers responsible for the various components by varying the stimulus intensity, by causing ischemic block of larger fibers and by estimating the afferent conduction velocities. The central pathways mediating these reflexes were examined by estimating central delays and by studying patients with focal lesions

Download Full-text

Effects of upper limb exercise programs on the arteriovenous fistula in patients on hemodialysis: A systematic review and meta-analysis

The Journal of Vascular Access ◽

10.1177/11297298211001166 ◽

2021 ◽

pp. 112972982110011

Author(s):

Francini Porcher Andrade ◽

Heloíse Benvenutti ◽

Kacylen Costa da Silva ◽

Paula Maria Eidt Rovedder

Keyword(s):

Systematic Review ◽

Arteriovenous Fistula ◽

Flow Rate ◽

Upper Limb ◽

Handgrip Strength ◽

Meta Analysis ◽

Blood Flow Rate ◽

Exercise Programs ◽

Exercise Interventions ◽

Limb Exercise

Background: The arteriovenous fistula (AVF) is a commonly used vascular access for chronic kidney disease (CKD) patients; exercise interventions may boost its maturation and help in its maintenance. A systematic review and meta-analysis of clinical trials on the effects of upper limb exercise programs on the AVF was conducted. Methods: The primary outcomes were draining vein diameter (DVD) and draining vein blood flow rate (DVBFR), and secondary outcomes were handgrip strength (HGS) and brachial artery flow rate (BAFR). Quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Results: Four studies met the inclusion criteria. When compared to usual care groups, the experimental groups did not improve DVD (mean difference [MD] 0.23, confidence interval [CI] −0.20–0.65). There were significant differences in DVBFR (mL/min) according to the fixed-effect model (MD 141.13, CI 36.84–245.42). HGS (kg) was significantly different between groups (MD 2.95, CI 0.55–5.35), but BAFR (mL/min) was not (MD 91.65, CI −94.72–278.01). Conclusions: Although exercise programs did not improve DVD and BAFR, they increased muscle strength and DVBFR. Therefore, experimental exercise programs should be emphasized for AVF maturation and maintenance. Research Registry number: reviewregistry924.

Download Full-text

Methodological consideration for the recruitment of upper limb muscles during two joint arm movements

2009 IEEE International Conference on Rehabilitation Robotics ◽

10.1109/icorr.2009.5209627 ◽

2009 ◽

Author(s):

Tasuku Miyoshi ◽

Yoshiyuki Takahashi ◽

Hokyoo Lee ◽

Masaki Yamaguchi ◽

Takashi Komeda

Keyword(s):

Upper Limb ◽

Arm Movements ◽

Methodological Consideration ◽

Limb Muscles

Download Full-text

Validity of Skeletal Muscle Ultrasound in Assessment of Suspected Limb Girdle Muscular Dystrophy Patients

QJM ◽

10.1093/qjmed/hcab102.023 ◽

2021 ◽

Vol 114 (Supplement_1) ◽

Author(s):

Rasha M Ibrahim ◽

Haitham M Hamdy ◽

Amr A Mohammed ◽

Ahmed M Elsadek ◽

Ahmed M Bassiouny ◽

...

Keyword(s):

Muscular Dystrophy ◽

Upper Limb ◽

Lower Limb ◽

Limb Girdle Muscular Dystrophy ◽

Ultrasound Images ◽

General Electric ◽

Cross Sectional ◽

Lower Limb Muscles ◽

Limb Muscles ◽

Muscle Ultrasound

Abstract Background Limb-girdle muscular dystrophies (LGMDs) are a clinically and genetically heterogeneous group of disorders characterized by progressive muscle weakness and degenerative muscle changes. Studies have shown that ultrasound can be useful both for diagnosis and follow-up of LGMDs patients. Objectives This study aims to measure the sensitivity and the specificity of muscle ultrasound in assessment of suspected limb girdle muscular dystrophy patients. Subjects and Methods This cross-sectional descriptive study was conducted on Fifty-five patients with suspected LGMD from neuromuscular unit, myology clinic, Ain Shams University hospitals and eight healthy subjects. Age was above 2 years. Both sexes were included in the study. They underwent real-time B-mode ultrasonography performed with using Logiq p9 General Electric ultrasound machine and General Electric 7-11.5 MHZ linear array ultrasound probe. All ultrasound images have been obtained and scored by a single examiner and muscle echo intensity was visually graded semiquantitative according to Heckmatt's scale. The examiner was blinded to the muscle biopsy results and clinical evaluations. Results Statistical analysis revealed that the diagnostic performance of muscle US (Heckmatt’s score) in LGMD is most sensitive when calculated in all examined upper limb and lower limb muscles, followed by lower limb muscles alone. US of upper limb was found to be the least sensitive. Conclusions Muscle ultrasound is a practical and reproducible and valid tool that can be used in assessment of suspected LGMD patients.

Download Full-text