Acute effects of quadriceps muscle versus tendon prolonged local vibration on force production capacities and central nervous system excitability

• Published in: European journal of applied physiology Vol. 122; no. 11; pp. 2451 - 2461
• Main Authors: Kennouche, Djahid, Varesco, Giorgio, Espeit, Loïc, Féasson, Léonard, Souron, Robin, Rozand, Vianney, Millet, Guillaume Y., Lapole, Thomas
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2022; Springer Nature B.V
• Subjects: Acute effects; Biomedical and Life Sciences; Biomedicine; Central nervous system; Electrical stimuli; Electromyography; Excitability; Human Physiology; Magnetic fields; Muscle contraction; Muscles; Nervous system; Occupational Medicine/Industrial Medicine; Original Article; Pyramidal tracts; Quadriceps muscle; Sports Medicine; Tendons; Thorax; Transcranial magnetic stimulation; Cortical excitability; Knee extensors; Maximal voluntary contraction; Transcranial magnetic stimulation; Local vibration; Motoneuron excitability
• ISSN: 1439-6319; 1439-6327
• DOI: 10.1007/s00421-022-05028-9

Purpose
The present study aimed to directly compare the effects of 30 min muscle (VIB
muscle
) vs. tendon (VIB
tendon
) local vibration (LV) to the quadriceps on maximal voluntary isometric contraction (MVIC) and rate of torque development (RTD) as well as on central nervous system excitability (i.e. motoneuron and cortical excitability).
Methods
Before (PRE) and immediately after (POST) LV applied to the quadriceps muscle or its tendon, we investigated MVIC and RTD (STUDY #1;
n
 = 20) or vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) electromyography responses to thoracic electrical stimulation (TMEPs; motoneuron excitability) and transcranial magnetic stimulation (MEPs; corticospinal excitability) (STUDY #2;
n
 = 17). MEP/TMEP ratios were further calculated to quantify changes in cortical excitability.
Results
MVIC decreased at POST (
P
 = 0.017) without any difference between VIB
tendon
and VIB
muscle
, while RTD decreased for VIB
tendon
(
P
 = 0.013) but not VIB
muscle
. TMEP amplitudes were significantly decreased for all muscles (
P
 = 0.014,
P
 < 0.001 and
P
 = 0.004 for VL, VM and RF, respectively) for both LV sites. While no changes were observed for MEP amplitude, MEP/TMEP ratios increased at POST for VM and RF muscles (
P
 = 0.009 and
P
 = 0.013, respectively) for both VIB
tendon
and VIB
muscle
.
Conclusion
The present results suggest that prolonged muscle and tendon LV are similarly effective in modulating central nervous system excitability and decreasing maximal force. Yet, altered explosive performance after tendon but not muscle LV suggests greater neural alterations when tendons are vibrated.