The effects of aging on the distribution and strength of correlated neural inputs to postural muscles during unperturbed bipedal stance

The present study investigated the effects of aging on the distribution of common descending neural drives to main postural muscles acting on the ankle, knee, hip, and lower trunk. The presence, distribution, and strength of these drives were assessed using intermuscular coherence estimations at a low-frequency band (0-55 Hz). Ten healthy older adults (68.7 ± 3.5 years) with no recent history of falls and ten healthy younger adults (26.8 ± 2.7 years) performed bipedal stances with eyes either opened or closed. Electromyographic (EMG) signals of six postural muscles were recorded. Estimations of intermuscular coherence were obtained from fifteen muscle pairs and four muscle groups. In general, single-pair and pooled coherence analyzes revealed significant levels of signal synchronization within 1-10 Hz. Significant common drives to anterior, posterior, and antagonist muscle groups were observed for both cohorts of participants. However, older participants showed significantly stronger EMG-EMG synchronization in the frequency domain compared to younger participants. It seems that age-related sarcopenia, visual-vestibular-proprioceptive decline, cortical activation increase, presynaptic inhibition modulation decrease, and co-contraction increase had a major impact on strengthening the common drives to the aforementioned muscle groups. Differently from young adults, the absence of visual inputs did not reduce the magnitude of signal synchronization in older adults. These results suggest that the aging central nervous system seems to organize similar arrangements of common drives to postural antagonist muscles at different joints, and to postural muscles pushing the body either forward or backward when visual information is not available.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:238

Enthalten in:

Experimental brain research - 238(2020), 6 vom: 11. Juni, Seite 1537-1553

Sprache:

Englisch

Beteiligte Personen:

Degani, Adriana M [VerfasserIn]
Leonard, Charles T [VerfasserIn]
Danna-Dos-Santos, Alessander [VerfasserIn]

Links:

Volltext

Themen:

Aging
Common drive
EMG–EMG coherence
Electromyogram
Intermuscular synchronization
Journal Article
Postural control

Anmerkungen:

Date Completed 10.03.2021

Date Revised 10.03.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s00221-020-05837-4

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM310337356