Abstract
Background.Age-related alterations of neuromuscular activation may contribute to deficits in muscle power and mobility function. This study assesses whether impaired activation of the agonist quadriceps and antagonist hamstrings, including amplitude-and velocity-dependent characteristics of activation, may explain differences in leg extension torque and power between healthy middle-aged, healthy older, and mobility-limited older adults.Methods.Torque, power, and electromyography were recorded during maximal voluntary leg extension trials across a range of velocities on an isokinetic dynamometer.Results.Neuromuscular activation was similar between middle-aged and older healthy groups, with differences in torque and power explained predominantly by muscle size. However, the older mobility-limited group demonstrated marked impairment of torque, power, and agonist muscle activation, with the greatest deficits occurring at the fastest movement velocities. Agonist muscle activation was found to be strongly associated with torque output.Conclusions.Similar neuromuscular activation between the middle-aged and older healthy groups indicates that impaired voluntary activation is not an obligatory consequence of aging. However, the finding that the mobility-limited group exhibited impaired activation of the agonist quadriceps and concomitant deficits in torque and power output suggests that neuromuscular activation deficits may contribute to compromised mobility function in older adults.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 495-502 |
| Number of pages | 8 |
| Journal | Journals of Gerontology - Series A Biological Sciences and Medical Sciences |
| Volume | 65 A |
| Issue number | 5 |
| DOIs | |
| State | Published - May 1 2010 |
| Externally published | Yes |
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Keywords
- Aging
- Electromyography
- Strength
ASJC Scopus subject areas
- Aging
- Geriatrics and Gerontology
Cite this
Impaired voluntary neuromuscular activation limits muscle power in mobility-limited older adults. / Clark, David J.; Patten, Carolynn; Reid, Kieran F.; Carabello, Robert J.; Phillips, Edward M.; Fielding, Roger A.
In: Journals of Gerontology - Series A Biological Sciences and Medical Sciences, Vol. 65 A, No. 5, 01.05.2010, p. 495-502.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Impaired voluntary neuromuscular activation limits muscle power in mobility-limited older adults
AU - Clark, David J.
AU - Patten, Carolynn
AU - Reid, Kieran F.
AU - Carabello, Robert J.
AU - Phillips, Edward M.
AU - Fielding, Roger A.
PY - 2010/5/1
Y1 - 2010/5/1
N2 - Background.Age-related alterations of neuromuscular activation may contribute to deficits in muscle power and mobility function. This study assesses whether impaired activation of the agonist quadriceps and antagonist hamstrings, including amplitude-and velocity-dependent characteristics of activation, may explain differences in leg extension torque and power between healthy middle-aged, healthy older, and mobility-limited older adults.Methods.Torque, power, and electromyography were recorded during maximal voluntary leg extension trials across a range of velocities on an isokinetic dynamometer.Results.Neuromuscular activation was similar between middle-aged and older healthy groups, with differences in torque and power explained predominantly by muscle size. However, the older mobility-limited group demonstrated marked impairment of torque, power, and agonist muscle activation, with the greatest deficits occurring at the fastest movement velocities. Agonist muscle activation was found to be strongly associated with torque output.Conclusions.Similar neuromuscular activation between the middle-aged and older healthy groups indicates that impaired voluntary activation is not an obligatory consequence of aging. However, the finding that the mobility-limited group exhibited impaired activation of the agonist quadriceps and concomitant deficits in torque and power output suggests that neuromuscular activation deficits may contribute to compromised mobility function in older adults.
AB - Background.Age-related alterations of neuromuscular activation may contribute to deficits in muscle power and mobility function. This study assesses whether impaired activation of the agonist quadriceps and antagonist hamstrings, including amplitude-and velocity-dependent characteristics of activation, may explain differences in leg extension torque and power between healthy middle-aged, healthy older, and mobility-limited older adults.Methods.Torque, power, and electromyography were recorded during maximal voluntary leg extension trials across a range of velocities on an isokinetic dynamometer.Results.Neuromuscular activation was similar between middle-aged and older healthy groups, with differences in torque and power explained predominantly by muscle size. However, the older mobility-limited group demonstrated marked impairment of torque, power, and agonist muscle activation, with the greatest deficits occurring at the fastest movement velocities. Agonist muscle activation was found to be strongly associated with torque output.Conclusions.Similar neuromuscular activation between the middle-aged and older healthy groups indicates that impaired voluntary activation is not an obligatory consequence of aging. However, the finding that the mobility-limited group exhibited impaired activation of the agonist quadriceps and concomitant deficits in torque and power output suggests that neuromuscular activation deficits may contribute to compromised mobility function in older adults.
KW - Aging
KW - Electromyography
KW - Strength
UR - http://www.scopus.com/inward/record.url?scp=77951886706&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77951886706&partnerID=8YFLogxK
U2 - 10.1093/gerona/glq012
DO - 10.1093/gerona/glq012
M3 - Article
VL - 65 A
SP - 495
EP - 502
JO - The journals of gerontology. Series A, Biological sciences and medical sciences
JF - The journals of gerontology. Series A, Biological sciences and medical sciences
SN - 1079-5006
IS - 5
ER -