yes, a cushion, but every one I’ve found is too big and doesn’t fir my backpack where I have more stuff (clothes, an umbrella…).
I like doing yoga and stretching outdoors, so the ground may also have loose dirt, broken pebbles and grass…
If I bend on my fours, raise-stretch a leg with the other leg’s knee touching the ground to hold most of my weight with this leg’s foot stretched to the back and still touching the ground, raise-stretching one arm and only using the other arm not to fall to the ground, the knee touching the ground hurts.
I’ve tried folding a small towel three times, but I’m so skinny that my knee still hurts.
Folding a yoga mat doesn’t help either.
What works for you?
Hover your knee off the ground when you are in the all-fours helps. Like don’t put your whole weight on it. Do poses that don’t put as much weight on your knees. Look for better ground to practice, grassy areas.
When I yoga outside, it’s the last suggestion I use the most. My knees are also sensitive, and finding a flat surface, then using my usual sorta thick yoga mat works well.