Fig. 6From: Global trends in research on extracorporeal shock wave therapy (ESWT) from 2000 to 2021The visualization mountain map. The volume of the hill is proportional to the intra-class similarity, and the height is proportional to the number of keywords contained within the cluster. The color of the mountain is related to the standard deviation within the class. Red means low standard deviation, and blue means high standard deviationBack to article page