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?
Hardware stores might have cheap gel knee pads ($10 -> $40 for fancier ones)
There’s also these kneeling mats / pads
Hunting/sports sections will have foam pads like these for sitting on while hunting/fishing or in bleachers etc. Have had one in my gym bag for years for knee-ground-exercise things.