Age-Related Increase in Electromyography Burst Activity in Males and Females

Theou, Olga; Edwards, David R.; Jones, Gareth R.; Jakobi, Jennifer M.

doi:10.1155/2013/720246

Cited by 11 publications

(6 citation statements)

References 36 publications

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“…The limb differences between young and old adults may be related to activity levels. Self-reported physical activity levels were less in the old adults compared with young adults, possibly more reflective of differences in the lower limb than upper limb activity (Kern and others 2001; Theou and others 2013). Regardless, age differences in fatigability of the lower limb, persist even between young and old adults who were matched for physical activity levels (Callahan and Kent-Braun 2011; Dalton and others 2012) indicating that age differences in activity levels probably do not entirely explain the age difference in fatigability.…”

Section: Discussionmentioning

confidence: 95%

Age differences in dynamic fatigability and variability of arm and leg muscles: Associations with physical function

Senefeld

Yoon

Hunter

2017

Experimental Gerontology

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Introduction It is not known whether the age-related increase in fatigability of fast dynamic contractions in lower limb muscles also occurs in upper limb muscles. We compared age-related fatigability and variability of maximal-effort repeated dynamic contractions in the knee extensor and elbow flexor muscles; and determined associations between fatigability, variability of velocity between contractions and functional performance. Methods 35 young (16 males; 21.0±2.6 years) and 32 old (18 males; 71.3±6.2 years) adults performed a dynamic fatiguing task involving 90 maximal-effort, fast, concentric, isotonic contractions (1 contraction/3 s) with a load equivalent to 20% maximal voluntary isometric contraction (MVIC) torque with the elbow flexor and knee extensor muscles on separate days. Old adults also performed tests of balance and walking endurance. Results Old adults had greater fatigue-related reductions in peak velocity compared with young adults for both the elbow flexor and knee extensor muscles (P<0.05) with no sex differences (P>0.05). Old adults had greater variability of peak velocity during the knee extensor, but not during the elbow flexor fatiguing task. The age difference in fatigability was greater for the knee extensor muscles (35.9%) compared with elbow flexor muscles (9.7%, P<0.05). Less fatigability of the knee extensor muscles was associated with greater walking endurance (r=−0.34, P=0.048) and balance (r=−0.41, P=0.014) among old adults. Conclusions An age-related increase in fatigability of a dynamic fatiguing task was greater for the knee extensor compared with the elbow flexor muscles in males and females, and greater fatigability was associated with lesser walking endurance and balance.

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Section: Discussionmentioning

confidence: 95%

Age differences in dynamic fatigability and variability of arm and leg muscles: Associations with physical function

Senefeld

Yoon

Hunter

2017

Experimental Gerontology

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“…These two muscles were considered as representative of upper and lower limbs 27 muscle respectively as previously reported (Bazzucchi et al 2004;Harwood et al 28 2008;Theou et al 2013). After gentle skin abrasion and cleaning with ethyl alcohol, 29 electrodes were attached on the skin over the BB along the line connecting the 1 acromion to the cubital fossa, and over the VL on the line from the anterior spina 2 iliaca superior to the lateral side of the patella.…”

Section: Methodsmentioning

confidence: 99%

Effect of exercise training on neuromuscular function of elbow flexors and knee extensors of type 2 diabetic patients

Bazzucchi

Vito

Felici

et al. 2015

Journal of Electromyography and Kinesiology

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Massimo (2015) Effect of exercise training on neuromuscular function of elbow flexors and knee extensors of type 2 diabetic patients. Journal of Electromyography and Kinesiology, 25 (5). pp. 815-823.Downloaded from: http://insight.cumbria.ac.uk/2048/ Usage of any items from the University of Cumbria's institutional repository 'Insight' must conform to the following fair usage guidelines.Any item and its associated metadata held in the University of Cumbria's institutional repository Insight (unless stated otherwise on the metadata record) may be copied, displayed or performed, and stored in line with the JISC fair dealing guidelines (available here) for educational and not-for-profit activities provided that• the authors, title and full bibliographic details of the item are cited clearly when any part of the work is referred to verbally or in the written form• a hyperlink/URL to the original Insight record of that item is included in any citations of the work • the content is not changed in any way• all files required for usage of the item are kept together with the main item file. You may not• sell any part of an item• refer to any part of an item without citation • amend any item or contextualise it in a way that will impugn the creator's reputation• remove or alter the copyright statement on an item.The full policy can be found here. Alternatively contact the University of Cumbria Repository Editor by emailing insight@cumbria.ac.uk. Accepted Manuscript

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“…Similar results were shown by quantifying age-related differences in burst activity measured by EMG. Interestingly, muscles of old adults (adults > 70 years old) exhibited longer burst duration with higher mean amplitudes over an 8 h recording when compared to young adults (adults < 26 years old) (Theou et al, 2013). With this precedent in mind, our results on ALS MNs suggest that perturbations in MNs bursting patterns in cell culture could provide early prodromal mechanistic insight.…”

Section: Discussionmentioning

confidence: 64%

Human Motor Neurons With SOD1-G93A Mutation Generated From CRISPR/Cas9 Gene-Edited iPSCs Develop Pathological Features of Amyotrophic Lateral Sclerosis

Kim

Ryu

Jeong

et al. 2020

Front. Cell. Neurosci.

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Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by gradual degeneration and elimination of motor neurons (MNs) in the motor cortex, brainstem, and spinal cord. Some familial forms of ALS are caused by genetic mutations in superoxide dismutase 1 (SOD1) but the mechanisms driving MN disease are unclear. Identifying the naturally occurring pathology and understanding how this mutant SOD1 can affect MNs in translationally meaningful ways in a valid and reliable human cell model remains to be established. Here, using CRISPR/Cas9 genome editing system and human induced pluripotent stem cells (iPSCs), we generated highly pure, iPSCderived MNs with a SOD1-G93A missense mutation. With the wild-type cell line serving as an isogenic control and MNs from a patient-derived iPSC line with an SOD1-A4V mutation as a comparator, we identified pathological phenotypes relevant to ALS. The mutant MNs accumulated misfolded and aggregated forms of SOD1 in cell bodies and processes, including axons. They also developed distinctive axonal pathologies. Mutants had axonal swellings with shorter axon length and less numbers of branch points. Moreover, structural and molecular abnormalities in presynaptic and postsynaptic size and density were found in the mutants. Finally, functional studies with microelectrode array demonstrated that the individual mutant MNs exhibited decreased number of spikes and diminished network bursting, but increased burst duration. Taken together, we identified spontaneous disease phenotypes relevant to ALS in mutant SOD1 MNs from genome-edited and patient-derived iPSCs. Our findings demonstrate that SOD1 mutations in human MNs cause cell-autonomous proteinopathy, axonopathy, synaptic pathology, and aberrant neurotransmission.

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Age-Related Increase in Electromyography Burst Activity in Males and Females

Cited by 11 publications

References 36 publications

Age differences in dynamic fatigability and variability of arm and leg muscles: Associations with physical function

Age differences in dynamic fatigability and variability of arm and leg muscles: Associations with physical function

Effect of exercise training on neuromuscular function of elbow flexors and knee extensors of type 2 diabetic patients

Human Motor Neurons With SOD1-G93A Mutation Generated From CRISPR/Cas9 Gene-Edited iPSCs Develop Pathological Features of Amyotrophic Lateral Sclerosis

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