I worked in a call center before for just 2 months because I resigned early for some reasons. One of these is having a muscle pain when Im at work, My muscle pain which is located at the upper left back was triggered by an aircon. Every time I did calls that time I normally felt the pain and noticed that the pain increased day by day. The question is what is the cost of muscle pain and how to avoid such? Perhaps some of you guys know the answers for this.