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Oxygen uptake and muscle activity limitations during stepping on a stair machine at three different climbing speeds

Halder, Amitava LU ; Gao, Chuansi LU ; Miller, Michael LU and Kuklane, Kalev LU (2018) In Ergonomics
Abstract
This laboratory study examined human stair ascending capacity and constraining factors including legs’ local muscle fatigue (LMF) and cardiorespiratory capacity. Twenty-five healthy volunteers, mean age 35.3 years, with maximal oxygen uptake (VO2max) of 46.7 mL·min-1·kg-1, and maximal heart rate of 190 bpm, ascended on a stair machine at 60% and 75% (3 min each), and 90% of VO2max (5 min or until exhaustion). The VO2, HR and electromyography (EMG) of the leg muscles were measured. The average VO2highest reached 43.9mL·min-1·kg-1,and HRhighest peaked at 185 bpm at 90%of VO2max step rate... (More)
This laboratory study examined human stair ascending capacity and constraining factors including legs’ local muscle fatigue (LMF) and cardiorespiratory capacity. Twenty-five healthy volunteers, mean age 35.3 years, with maximal oxygen uptake (VO2max) of 46.7 mL·min-1·kg-1, and maximal heart rate of 190 bpm, ascended on a stair machine at 60% and 75% (3 min each), and 90% of VO2max (5 min or until exhaustion). The VO2, HR and electromyography (EMG) of the leg muscles were measured. The average VO2highest reached 43.9mL·min-1·kg-1,and HRhighest peaked at 185 bpm at 90%of VO2max step rate (SR). EMG amplitudes significantly increased at all three levels, p<0.05, and median frequencies decreased mostly at 90% of VO2maxSR evidencing leg LMF. Muscle activity interpretation squares were developed and effectively used to observe changes over time, confirming LMF. The combined effects of LMF and cardiorespiratory constraints reduced ascending tolerance and constrained the duration to 4.32 minutes. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Stair climbing, Ascending Capacity, Oxygen Consumption, Electromyography, Muscle fatigue
in
Ergonomics
publisher
Taylor & Francis
ISSN
0014-0139
DOI
10.1080/00140139.2018.1473644
language
English
LU publication?
yes
id
7c3ffff8-ae04-4ff3-a728-e48c83a59506
date added to LUP
2018-03-17 12:55:10
date last changed
2019-05-29 04:00:33
@article{7c3ffff8-ae04-4ff3-a728-e48c83a59506,
  abstract     = {This laboratory study examined human stair ascending capacity and constraining factors including legs’ local muscle fatigue (LMF) and cardiorespiratory capacity. Twenty-five healthy volunteers, mean age 35.3 years, with maximal oxygen uptake (VO<sub>2max</sub>) of 46.7 mL·min<sup>-1</sup>·kg<sup>-1</sup>, and maximal heart rate of 190 bpm, ascended on a stair machine at 60% and 75% (3 min each), and 90% of VO<sub>2max </sub>(5 min or until exhaustion). The VO<sub>2</sub>, HR and electromyography (EMG) of the leg muscles were measured.<b style="mso-bidi-font-weight:normal"> </b>The average VO<sub>2highest </sub>reached 43.9mL·min<sup>-1</sup>·kg<sup>-1</sup>,and HR<sub>highest</sub> peaked at 185 bpm at 90%of VO<sub>2max </sub>step rate (SR). EMG amplitudes significantly increased at all three levels, <i style="mso-bidi-font-style:normal">p</i>&lt;0.05, and median frequencies decreased mostly at 90% of VO<sub>2max</sub>SR evidencing leg LMF. Muscle activity interpretation squares were developed and effectively used to observe changes over time, confirming LMF. The combined effects of LMF and cardiorespiratory constraints reduced ascending tolerance and constrained the duration to 4.32 minutes.},
  author       = {Halder, Amitava and Gao, Chuansi and Miller, Michael and Kuklane, Kalev},
  issn         = {0014-0139},
  keyword      = {Stair climbing,Ascending Capacity,Oxygen Consumption,Electromyography,Muscle fatigue},
  language     = {eng},
  month        = {08},
  publisher    = {Taylor & Francis},
  series       = {Ergonomics},
  title        = {Oxygen uptake and muscle activity limitations during stepping on a stair machine at three different climbing speeds},
  url          = {http://dx.doi.org/10.1080/00140139.2018.1473644},
  year         = {2018},
}