Effect of vibration stimulation on recovery of muscle stiffness after isometric muscle contraction had acheived fatigue

Abstract

The purpose of this study was to clarify which of the excitability effect caused by tonic vibration reflex, or the inhibitory effect from vibration stimulation, affected muscle stiffness in muscle fatigue. With 20 healthy students (average age, 24.4) as subjects, we investigated and compared the changes in muscle stiffness in the cases of applying or not applying vibration stimulation for 5 minutes directly after equivalent exercise measures to achieve muscle fatigue. At maximum effort, muscle fatigue was created by the equivalent exercise measure, and recovery from the consequent increase in muscle stiffness showed a delay of more than 5, but less than 15 minutes, due to the application of vibration stimulation. The excitability effect due to the tonic vibration reflex significantly affects fatigued muscles, and in addition we conjecture that through the accumulation of metabolites in the affected area due to lowering of the elimination effect of blood flow cut off, vibration stimulation was not effective at reducing muscle stiffness. However, since muscle stiffness recovered to pre-exercise levels within 15 minutes of the end of exercise, we consider that the increase in muscle stiffness was transitory, and comparatively short in nature.