Kathisophobia

KATHISOPHOBIA (kath·i·so·pho·bia\ˌkath-i-sō-ˈfō-bē-ə\), noun.
DEFINITION: fear of sitting.
EXAMPLE: Surrounded by chairs, beanbags and comfy sofas, Billy succumbed to his kathisophobia and crumpled into a little ball on the floor.