I assume this has something to do with the size of your feet. The limiting factor seems to be how far you stand from the wall. I can do it in socks but not in shoes.

Interesting in any case.

It’s about the distance your toes are from the wall. Her toes were up against the wall, and tight to her heels…his were away from the wall and stretched out to barely touch his heel. That one or two extra inches makes all the difference.
I can do it easily in socks, only sometimes in shoes.

https://www.youtube.com/watch?v=mnl2_zyLhtY

Math Dad vs Science Mom - length of feet, plus a bit of pear shaped females vs upside down triangle men. Just an inch or two in distance from the wall makes a big deal in the lever mechanics.

Moving this video to BSR's personal queue. It failed to receive enough votes to get sifted up to the front page within 2 days.