Neural adaptations in quadriceps muscle after 4 weeks of local vibration training in young versus older subjects.
This study investigated the effects of a 4-week local vibration training (LVT) on the function of the knee extensors and corticospinal properties in healthy young and older subjects. Seventeen subjects (9 young and 8 older) performed 3 testing sessions: before (PRE1) and after (PRE2) a 4-week resting period to control the repeatability of the data as well as after the LVT (POST). Jump performance, maximal voluntary contraction (MVC) and electromyographic (EMG) activity on vastus lateralis and rectus femoris muscles were assessed. Single-pulse transcranial magnetic stimulation (TMS) allowed evaluation of cortical voluntary activation (VATMS), motor evoked potential (MEP) area, and silent period (SP) duration. All training adaptations were similar between young and older subjects (p > 0.05) and the following results reflect the pooled sample of subjects. MVC (+11.9% ± 8.0%, p < 0.001) and VATMS (+3.6% ± 5.2%, p = 0.004) were significantly increased at POST compared with PRE2. Maximal vastus lateralis EMG was significantly increased at POST (+21.9% ± 33.7%, p = 0.03). No changes were reported for MEPs on both muscles (p > 0.05). SPs recorded during maximal and submaximal contractions decreased in both muscles at POST (p < 0.05). Vertical jump performance was increased at POST (p < 0.05). LVT seems as effective in young as in older subjects to improve maximal functional capacities through neural modulations occurring at least partly at the supra-spinal level. Local vibration may be used as an efficient alternative training method to improve muscular performance in both healthy young and older subjects.
['Souron|Robin|R|', 'Besson|Thibault|T|', 'Lapole|Thomas|T|', 'Millet|Guillaume Y|GY|']
D000222:Adaptation, Physiological D000328:Adult D000368:Aged D004576:Electromyography D019054:Evoked Potentials, Motor D015444:Exercise D005260:Female D006801:Humans D007537:Isometric Contraction D007717:Knee D008297:Male D008875:Middle Aged D009119:Muscle Contraction D052097:Quadriceps Muscle D012146:Rest D011795:Surveys and Questionnaires D050781:Transcranial Magnetic Stimulation D014732:Vibration D055815:Young Adult
local vibration training transcranial magnetic stimulation cortical voluntary activation activation corticale volontaire corticospinal excitability and inhibition entraînement par vibration locale excitabilité et inhibition corticospinale older population population âgée stimulation magnétique transcrânienne