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RESEARCH PRODUCT
Neural Activation During Submaximal Contractions Seems More Reflective of Neuromuscular Ageing than Maximal Voluntary Activation
Alain MartinAlain MartinGil ScaglioniGil ScaglioniMarco Naricisubject
AgingContraction (grammar)Voluntary activationAgeing.torquein-vivoPlantar flexionActivation patternh-reflex0302 clinical medicineVoluntary contractionmotor unitaging; clinical article; female; human; male; muscle contractility; muscle twitch; nervous system; torque; Ageing; Triceps surae; Twitch interpolation; Voluntary activation; Voluntary contractionTwitch interpolationolder-adultsmuscle contractilityOriginal Researchclinical articlenervous systemmuscle twitchfemalecross-sectional areaCardiologyTriceps suraeforcemedicine.medical_specialtymechanical-propertiesCognitive Neurosciencelcsh:RC321-57103 medical and health sciencesmaleInternal medicinemedicinehumanlcsh:Neurosciences. Biological psychiatry. Neuropsychiatryskeletal-muscle fibersbusiness.industryTwitch interpolation030229 sport sciencesAgeingageAgeingTurnover[ SDV.NEU ] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]interpolated twitchPhysical therapybusinessVoluntary contraction030217 neurology & neurosurgeryNeurosciencedescription
International audience; This study aimed at testing the hypothesis that differences in neural activation strategy during submaximal but not maximal plantarflexions exist between young and older men. Eleven young men (YM, 26 +/- 4 years) and thirteen old men (OM, 76 +/- 3 years) volunteered for the investigation. Maximal voluntary torque (MVT) was 38.2%, lower (p < 0.001) in OM than in YM, while voluntary activation was equivalent (similar to 97%). The relationship between the interpolated twitch torque and the voluntary torque (IT-VT relationship) was composite (curvilinear + exponential) for both age-groups. However, the OM showed accentuated concavity, as attested by the occurrence of the deviation from linearity at a lower contraction intensity (OM: 54.9 vs. YM: 71.9% MVT). In conclusion, ageing does not affect the capacity to fully activate the plantar flexors during maximal performances, but it alters the activation pattern for submaximal levels of effort. The greater age-related concavity of the IT-VT relationship suggests that, during submaximal contractions, OM need to reach a level of activation higher than YM to develop an equivalent relative torque.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-02-25 | Frontiers in Aging Neuroscience |