Postural challenge affects motor cortical activity in young and old adults.
- Papegaaij S University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Antonius Deusinglaan 1, 9713AV, Groningen, The Netherlands. Electronic address: s.papegaaij@umcg.nl.
- Taube W University of Fribourg, Department of Medicine, Ch. du Musée 8, CH-1700, Fribourg, Switzerland.
- van Keeken HG University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Antonius Deusinglaan 1, 9713AV, Groningen, The Netherlands.
- Otten E University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Antonius Deusinglaan 1, 9713AV, Groningen, The Netherlands.
- Baudry S Université Libre de Bruxelles, Faculty for Motor Sciences, Laboratory of Applied Biology, CP 640, Route de Lennik 808, 1070 Brussels, Belgium.
- Hortobágyi T University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Antonius Deusinglaan 1, 9713AV, Groningen, The Netherlands; Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle-upon-Tyne NE1 8ST, United Kingdom.
- 2015-12-01
Published in:
- Experimental gerontology. - 2016
Aging
Balance
Intracortical inhibition
Postural activation
Transcranial magnetic stimulation
Voluntary activation
Adult
Aged
Aged, 80 and over
Aging
Electromyography
Fatigue
Humans
Middle Aged
Motor Cortex
Muscle Contraction
Muscle, Skeletal
Postural Balance
Posture
Transcranial Magnetic Stimulation
Young Adult
English
When humans voluntarily activate a muscle, intracortical inhibition decreases. Such a decrease also occurs in the presence of a postural challenge and more so with increasing age. Here, we examined age-related changes in motor cortical activity during postural and non-postural contractions with varying levels of postural challenge. Fourteen young (age 22) and twelve old adults (age 70) performed three conditions: (1) voluntary contraction of the soleus muscle in sitting and (2) leaning forward while standing with and (3) without being supported. Subthreshold transcranial magnetic stimulation was applied to the soleus motor area suppressing ongoing EMG, as an index of motor cortical activity. The area of EMG suppression was ~60% smaller (p<0.05) in unsupported vs. supported leaning and sitting, with no difference between these latter two conditions (p>0.05). Even though in absolute terms young compared with old adults leaned farther (p=0.018), there was no age effect or an age by condition interaction in EMG suppression. Leaning closer to the maximum without support correlated with less EMG suppression (rho=-0.44, p=0.034). We conclude that the critical factor in modulating motor cortical activity was postural challenge and not contraction aim or posture. Age did not affect the motor control strategy as quantified by the modulation of motor cortical activity, but the modulation appeared at a lower task difficulty with increasing age.
- Language
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- English
- Open access status
- green
- Identifiers
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- DOI 10.1016/j.exger.2015.11.015
- PMID 26615878
- Persistent URL
- https://sonar.ch/global/documents/189500
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