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Neuromuscular Impairment Following Backpack Load Carriage
Load Carriage using backpacks is an occupational task and can be a recreational pursuit. The aim of this study was to investigate the mechanisms responsible for changes in neuromuscular function of the m. quadriceps femoris following load carriage. The physiological responses of 10 male participants...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Akademia Wychowania Fizycznego w Katowicach
201
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3796847/ https://www.ncbi.nlm.nih.gov/pubmed/24146709 http://dx.doi.org/ 10.2478/hukin-2013-0029 |
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author | Blacker, Sam D. Fallowfield, Joanne L. Bilzon, James L.J. Willems, Mark E.T. |
author_facet | Blacker, Sam D. Fallowfield, Joanne L. Bilzon, James L.J. Willems, Mark E.T. |
author_sort | Blacker, Sam D. |
collection | PubMed |
description | Load Carriage using backpacks is an occupational task and can be a recreational pursuit. The aim of this study was to investigate the mechanisms responsible for changes in neuromuscular function of the m. quadriceps femoris following load carriage. The physiological responses of 10 male participants to voluntary and electrically stimulated isometric contractions were measured before and immediately after two hours of treadmill walking at 6.5 km•h ( −1 ) during level walking with no load [LW], and level walking with load carriage (25 kg backpack) [LC]. Maximal voluntary contraction force decreased by 15 ± 11 % following LC (p=0.006), with no change following LW (p=0.292). Voluntary activation decreased after LW and LC (p=0.033) with no difference between conditions (p=0.405). Doublet contraction time decreased after both LW and LC (p=0.002), with no difference between conditions (p=0.232). There were no other changes in electrically invoked doublet parameters in either condition. The 20:50 Hz ratio did not change following LW (p=0.864) but decreased from 0.88 ± 0.04 to 0.84 ± 0.04 after LC (p=0.011) indicating reduced Ca2+ release from the sarcoplasmic reticulum during excitation contraction coupling. In conclusion, two hours of load carriage carrying a 25 kg back pack caused neuromuscular impairment through a decrease in voluntary activation (i.e. central drive) and fatigue or damage to the peripheral muscle, including impairment of the excitation contraction coupling process. This may reduce physical performance and increase the risk of musculoskeletal injury. |
format | Online Article Text |
id | pubmed-3796847 |
institution | National Center for Biotechnology Information |
language | English |
publishDate |
201 |
publisher |
Akademia Wychowania Fizycznego w Katowicach
|
record_format | MEDLINE/PubMed |
spelling | pubmed-37968472013-10-21 Neuromuscular Impairment Following Backpack Load Carriage Blacker, Sam D. Fallowfield, Joanne L. Bilzon, James L.J. Willems, Mark E.T. J Hum Kinet Research Article Load Carriage using backpacks is an occupational task and can be a recreational pursuit. The aim of this study was to investigate the mechanisms responsible for changes in neuromuscular function of the m. quadriceps femoris following load carriage. The physiological responses of 10 male participants to voluntary and electrically stimulated isometric contractions were measured before and immediately after two hours of treadmill walking at 6.5 km•h ( −1 ) during level walking with no load [LW], and level walking with load carriage (25 kg backpack) [LC]. Maximal voluntary contraction force decreased by 15 ± 11 % following LC (p=0.006), with no change following LW (p=0.292). Voluntary activation decreased after LW and LC (p=0.033) with no difference between conditions (p=0.405). Doublet contraction time decreased after both LW and LC (p=0.002), with no difference between conditions (p=0.232). There were no other changes in electrically invoked doublet parameters in either condition. The 20:50 Hz ratio did not change following LW (p=0.864) but decreased from 0.88 ± 0.04 to 0.84 ± 0.04 after LC (p=0.011) indicating reduced Ca2+ release from the sarcoplasmic reticulum during excitation contraction coupling. In conclusion, two hours of load carriage carrying a 25 kg back pack caused neuromuscular impairment through a decrease in voluntary activation (i.e. central drive) and fatigue or damage to the peripheral muscle, including impairment of the excitation contraction coupling process. This may reduce physical performance and increase the risk of musculoskeletal injury. Akademia Wychowania Fizycznego w Katowicach 2013 -07- 05 /pmc/articles/PMC3796847/ /pubmed/24146709 http://dx.doi.org/ 10.2478/hukin-2013-0029 Text en © Editorial Committee of Journal of Human Kinetics This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/). |
spellingShingle | Research Article Blacker, Sam D. Fallowfield, Joanne L. Bilzon, James L.J. Willems, Mark E.T. Neuromuscular Impairment Following Backpack Load Carriage |
title |
Neuromuscular Impairment Following Backpack Load Carriage
|
title_full |
Neuromuscular Impairment Following Backpack Load Carriage
|
title_fullStr |
Neuromuscular Impairment Following Backpack Load Carriage
|
title_full_unstemmed |
Neuromuscular Impairment Following Backpack Load Carriage
|
title_short |
Neuromuscular Impairment Following Backpack Load Carriage
|
title_sort | neuromuscular impairment following backpack load carriage |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3796847/ https://www.ncbi.nlm.nih.gov/pubmed/24146709 http://dx.doi.org/ 10.2478/hukin-2013-0029 |
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