Robert W Smith, Terry J Housh, John Paul V Anders, Tyler J Neltner, Jocelyn E Arnett, Richard J Schmidt, Glen O Johnson
{"title":"在持续等距前臂屈曲任务中，扭矩和神经肌肉参数的时间变化过程锚定在感知劳累的恒定等级。","authors":"Robert W Smith, Terry J Housh, John Paul V Anders, Tyler J Neltner, Jocelyn E Arnett, Richard J Schmidt, Glen O Johnson","doi":"","DOIUrl":null,"url":null,"abstract":"<p><strong>Objective: </strong>This study examined the time course of changes in torque and electromyographic (EMG) and mechanomyographic (MMG) responses during a sustained isometric task anchored to a constant perception of exertion (RPE).</p><p><strong>Methods: </strong>Twelve college-aged men performed an isometric forearm flexion task to failure anchored to RPE=7 (OMNI-RES scale). The amplitude (AMP) and frequency (MPF) of the EMG and MMG signals from the biceps brachii were recorded. Repeated measures ANOVAs were used to examine differences for the normalized (%MVIC) torque and neuromuscular parameters.</p><p><strong>Results: </strong>The time to task failure (TTF) was 678.0±468.1s. Torque decreased significantly (p<0.001, η<sub>p</sub><sup>2</sup>=0.774) across time and all subjects reduced torque to zero. Post-hoc comparisons indicated that the torque values from 20-100% TTF were less than the value at 10% TTF. There were no significant (p>0.05) changes from 10-100% TTF for the EMG and MMG parameters.</p><p><strong>Conclusion: </strong>We hypothesize that RPE was maintained by various mechanisms throughout the task: group III/IV afferent neurons, adequate blood flow, and a combination of reduced contractile efficiency, collective afferent feedback (group III/IV afferents) from muscles involved with forearm flexion, and motivation that resulted in an initial decrease, plateau, and final decline in torque to zero, respectively.</p>","PeriodicalId":16430,"journal":{"name":"Journal of musculoskeletal & neuronal interactions","volume":"22 4","pages":"455-464"},"PeriodicalIF":1.7000,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/cd/5f/JMNI-22-455.PMC9716304.pdf","citationCount":"0","resultStr":"{\"title\":\"Time course of changes in torque and neuromuscular parameters during a sustained isometric forearm flexion task to fatigue anchored to a constant rating of perceived exertion.\",\"authors\":\"Robert W Smith, Terry J Housh, John Paul V Anders, Tyler J Neltner, Jocelyn E Arnett, Richard J Schmidt, Glen O Johnson\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Objective: </strong>This study examined the time course of changes in torque and electromyographic (EMG) and mechanomyographic (MMG) responses during a sustained isometric task anchored to a constant perception of exertion (RPE).</p><p><strong>Methods: </strong>Twelve college-aged men performed an isometric forearm flexion task to failure anchored to RPE=7 (OMNI-RES scale). The amplitude (AMP) and frequency (MPF) of the EMG and MMG signals from the biceps brachii were recorded. Repeated measures ANOVAs were used to examine differences for the normalized (%MVIC) torque and neuromuscular parameters.</p><p><strong>Results: </strong>The time to task failure (TTF) was 678.0±468.1s. Torque decreased significantly (p<0.001, η<sub>p</sub><sup>2</sup>=0.774) across time and all subjects reduced torque to zero. Post-hoc comparisons indicated that the torque values from 20-100% TTF were less than the value at 10% TTF. There were no significant (p>0.05) changes from 10-100% TTF for the EMG and MMG parameters.</p><p><strong>Conclusion: </strong>We hypothesize that RPE was maintained by various mechanisms throughout the task: group III/IV afferent neurons, adequate blood flow, and a combination of reduced contractile efficiency, collective afferent feedback (group III/IV afferents) from muscles involved with forearm flexion, and motivation that resulted in an initial decrease, plateau, and final decline in torque to zero, respectively.</p>\",\"PeriodicalId\":16430,\"journal\":{\"name\":\"Journal of musculoskeletal & neuronal interactions\",\"volume\":\"22 4\",\"pages\":\"455-464\"},\"PeriodicalIF\":1.7000,\"publicationDate\":\"2022-12-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/cd/5f/JMNI-22-455.PMC9716304.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of musculoskeletal & neuronal interactions\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"NEUROSCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of musculoskeletal & neuronal interactions","FirstCategoryId":"3","ListUrlMain":"","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"NEUROSCIENCES","Score":null,"Total":0}
Time course of changes in torque and neuromuscular parameters during a sustained isometric forearm flexion task to fatigue anchored to a constant rating of perceived exertion.
Objective: This study examined the time course of changes in torque and electromyographic (EMG) and mechanomyographic (MMG) responses during a sustained isometric task anchored to a constant perception of exertion (RPE).
Methods: Twelve college-aged men performed an isometric forearm flexion task to failure anchored to RPE=7 (OMNI-RES scale). The amplitude (AMP) and frequency (MPF) of the EMG and MMG signals from the biceps brachii were recorded. Repeated measures ANOVAs were used to examine differences for the normalized (%MVIC) torque and neuromuscular parameters.
Results: The time to task failure (TTF) was 678.0±468.1s. Torque decreased significantly (p<0.001, ηp2=0.774) across time and all subjects reduced torque to zero. Post-hoc comparisons indicated that the torque values from 20-100% TTF were less than the value at 10% TTF. There were no significant (p>0.05) changes from 10-100% TTF for the EMG and MMG parameters.
Conclusion: We hypothesize that RPE was maintained by various mechanisms throughout the task: group III/IV afferent neurons, adequate blood flow, and a combination of reduced contractile efficiency, collective afferent feedback (group III/IV afferents) from muscles involved with forearm flexion, and motivation that resulted in an initial decrease, plateau, and final decline in torque to zero, respectively.
期刊介绍：
The Journal of Musculoskeletal and Neuronal Interactions (JMNI) is an academic journal dealing with the pathophysiology and treatment of musculoskeletal disorders. It is published quarterly (months of issue March, June, September, December). Its purpose is to publish original, peer-reviewed papers of research and clinical experience in all areas of the musculoskeletal system and its interactions with the nervous system, especially metabolic bone diseases, with particular emphasis on osteoporosis. Additionally, JMNI publishes the Abstracts from the biannual meetings of the International Society of Musculoskeletal and Neuronal Interactions, and hosts Abstracts of other meetings on topics related to the aims and scope of JMNI.
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
