https://www.healthcentral.com/article/kneeling-feels-pebble-rock-hurts-so-bad-almost-fall
Osteoarthritis

Why Does it Feel like I'm on a Pebble or Rock when I Kneel?

    Answered by Christina Lasich, MD
    You should know: The answer above provides general health information that is not intended to replace medical advice or treatment recommendations from a qualified healthcare professional.