Effects of Transverse Friction Massage on the Electromechanical Delay Components and Fractal Dimension of Surface Electromyography in Quadriceps Muscles

The purpose of this study was to assess the effects transverse friction massage (TFM) on electromechanical delay components and complexity surface activity in rectus femoris (RF) vastus medialis (VM) muscles identify possible mechanisms behind TFM-induced alterations dynamics RF VM activity. Seven female five male healthy subjects participated study. generated maximal voluntary isometric contractions (MVICs) consecutively before after TFM. Meanwhile, electromyography (EMG), mechanomyography (MMG), force were recorded. onset times recorded signals detected offline by setting threshold three SD baseline. delays between EMG MMG (Δt(EMG–MMG)), (Δt(MMG–Force)), (Δt(EMG–Force)) computed from onsets. fractal dimension (FD) time series using correlation method. TFM increased Δt(MMG–Force) Δt(EMG–Force) significantly but decreased Δt(EMG–MMG) VM. FD it results imply that stiffness both duration electrochemical processes It is proposed decrease may be associated with RF, increase muscle. also suggested opposite changes can used as a discriminating parameter search for an intervention quadriceps muscles. present demonstrates how discriminate nonlinear complex muscle system noisy series.