These guys inject steroids straight in the muscle which causes inflammations and many other problems, look for Greg Vallentino on you tube, they showed this on TV years ago, his skin torn up.
Total mess, look for the videos that explain his idiotic choices.
2X YY 97T 310 with YY PTSPIN 47/43. ---Yonex PC Light, waiting for VCore TourG. Stan is the MAN.