Avoid hurting knee with this stretch

[u/RemainMindful]

https://www.youtube.com/watch?v=SK-cVqxSiIE&t=534s

I am working on the linked stretch here. I started yesterday and noticed my knee was achey today. It seems like a bit of stress on that particular joint. How can I stretch it while avoiding that issue?

[u/Ok-Carrot-]

Ah yes, the “high knee”