I’ve been teaching hot yoga for 4+ years, but have never encountered this. Tonight, when we reached fixed firm pose and I said to sit Japanese style, one of my new students said, “I can’t sit that way, I have no cartilage in my knees.” I didn’t want to force her to do something she believed was harmful, so I told her to skip the next several postures and give me time to look into the issue. After class I inquired about the exact issue, and she said she was unkind to her knees, and the kneecap basically sits bone on bone against the joint. When (if) she comes back, how should she approach the “kneeling postures”? Any advice will be greatly appreciated.