You searched for: “cathisophobias
cathisophobia (s) (noun), cathisophobias (pl)
An excessive fear of sitting down: Anyone who is suffering with cathisophobia may find it extremely difficult to take a seat, especially in public, because that person may think that he or she is more vulnerable to mistreatment than when standing, and perhaps can run away faster!
kathisophobia, cathisophobia (s) (noun); kathisophobias, cathisophobias (pl)
1. An excessive or abnormal avoidance of taking a seat: When someone has kathisophobia or cathisophobia, he or she may actually have anxieties about being trapped or is unable to sit still.

A kathisophobia may become the source of fear because it can be painful or uncomfortable in some people, especially the elderly who may be forced to be seated for longer times than younger persons, simply because they are not as ambulatory or capable of walking.

2. Etymology: from Greek kathizein, "to sit down" + phobia, "strong" or "irrational fear".