<unk>  are a cutaneous condition caused by chronic pressure over bony prominences leading to thick fibrotic nodules on knees, knuckles, dorsal feet, often seen with those who perform surfing, boxing, football, and marbles.
Surfer's knots
Brock string
Mees' lines
Woronoff's ring
Kerley lines
Vossius ring
Moore's lightning streaks
Dennie–Morgan fold