Does anyone know what these guys wrap below their patella with and/or how it is done?
GEAR WHORE!
Kidding. Looks like they might be Chopat straps to help alleviate patellar tendinitis.
It’s just bandage, most likely for the patellar as Stronghold says. I’ve used them myself for that reason, just to keep the patellar tendon in its groove - I don’t like snatching in knee sleeves and Ace bandages give a little more compression.