Muscle motion and EMG activity in vibration treatment

Antonio Fratini, Antonio la Gatta, Paolo Bifulco, Maria Romano, Mario Cesarelli*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The aim of this study is to highlight the relationship between muscle motion, generated by whole body vibration, and the correspondent electromyographic (EMG) activity and to suggest a new method to customize the stimulation frequency. Simultaneous recordings of EMG and tri-axial accelerations of quadriceps rectus femoris from fifteen subjects undergoing vibration treatments were collected. Vibrations were delivered via a sinusoidal oscillating platform at different frequencies (10-45 Hz). Muscle motion was estimated by processing the accelerometer data. Large EMG motion artifacts were removed using sharp notch filters centred at the vibration frequency and its superior harmonics. EMG-RMS values were computed and analyzed before and after artifact suppression to assess muscular activity. Muscles acceleration amplitude increased with frequency. Muscle displacements revealed a mechanical resonant-like behaviour of the muscle. Resonance frequencies and dumping factors depended on subject. Moreover, RMS of artifact-free EMG was found well correlated (R 2 = 0.82) to the actual muscle displacement, while the maximum of the EMG response was found related to the mechanical resonance frequency of muscle. Results showed that maximum muscular activity was found in correspondence to the mechanical resonance of the muscle itself. Assuming the hypothesis that muscle activation is proportional to muscle displacement, treatment optimization (i.e. to choose the best stimulation frequency) could be obtained by simply monitoring local acceleration (resonance), leading to a more effective muscle stimulation. Motion artifact produced an overestimation of muscle activity, therefore its removal was essential.

Original languageEnglish
Pages (from-to)1166-1172
Number of pages7
JournalMedical Engineering and Physics
Issue number9
Early online date9 Aug 2009
Publication statusPublished - Nov 2009


  • electromyography
  • motion artifact
  • muscle motion
  • whole body vibration


Dive into the research topics of 'Muscle motion and EMG activity in vibration treatment'. Together they form a unique fingerprint.

Cite this