The purpose of this study was to investigate the effects of sling exercise on muscle activity and balance on football players with chronic ankle instability. Eight subjects performed Biodex and sling exercises for four weeks and compared the muscle activity and balance ability of the uninjured and injured feet. Stable and unstable foot % MVIC did not change significantly after treatment in all muscles. The total balance ability was not significantly different between the two groups, however, increased only in the unstable side. The anterior/posterior balance ability also represented no significant difference between the groups and was significantly improved only in the unstable side. The medial/lateral balance ability was not significantly different between the groups and was significantly improved only in the unstable side. This study suggests that sling exercise contributes to improving % MVIC, total balance ability, anterior/ posterior balance ability, and medial/lateral balance ability of the unstable side.

INTRODUCTION
 METHODS
  Subjects
  Measurement Muscle activity
  Data processing
 RESULTS
  Change of the %MVIC in each muscle
  Change of the anterior/posterior balance ability
  Change of medial/lateral balance ability
 DISCUSSION
 CONCLUSION
 REFERENCES

• Seong bum Hong(Samsung Mi Plus Hospital) correspondence