Background: It has been argued that changes in muscle activity in the upper trapezius and serratus anterior may or may not cause shoulder joint pain and dysfunction.
Objective: To investigate the effects of active vibration exercise on muscle activity regarding scapular stabilization using a flexi-bar.
Design: A randomized controlled trial.
Methods: A total of 24 subjects were randomly assigned to a flexi-bar group with active vibration and general stick group with non-active vibration. Both groups performed the same four action programs for 6 weeks, three times a week for 30 minutes at a time. The upper trapezius muscle, middle trapezius muscle, lower trapezius muscle and serratus anterior muscle of the dominant side was measured by electromyography before and after the 6 weeks of exercise. The independent t-test and paired t-test were used to analyze data. Results: There was a significant difference between groups in upper trapezius muscle and serratus anterior muscle activity after exercise (P<.05). Also, there was a significant difference in upper trapezius muscle and serratus anterior muscle activity before and after exercise in the flexi-bar group (P<.05).
Conclusion: This study demonstrates that active vibration exercise using a flexi-Bar contribute to reduce the activity of the upper trapezius muscle and promote the activity of the serratus anterior muscle.

INTRODUCTION
SUBJECTS AND METHODS
    Subjects
    Outcome Measures
    Data and Statistical Analysis
RESULTS
    Comparison of EMG between flexi-bar group and generalbar group
DISCUSSION
REFERENCES

• Chibok Park(Department of Physical Therapy, Chunnam Techno University)
• Byeonggeun Kim(Department of Physical Therapy, Nambu University) Correspondence