Yin / Yang
There is a very important difference between the muscles on the front and inside of your body and the muscles on the back and outside of your body. In TCM, the muscles on the front and inside are called yin and the muscles on the back and outside are called yang. Accumulated dense fascia and scar tissue (ADFST) is characteristically only in the yang muscle groups, except when unusual trauma has occurred. More specifically, there are eight yang muscle meridians and eight yin muscles meridians. Yin is characterized by feminine principles — passive, expansive, leadership, cold, darkness, completion, submission, etc. while yang is characterized by masculine principles — active, contractive, hot, brightness, cooperative, hard, dominance, the sun, etc.