Kneeling p. pr. & vb. n. : of Kneel

Example:
Where to put the keyboard when using a Kneeling chair?

Taxonomy
knee, attitude, posture, genuflect, prayer, rule, canon, Genuflexion, the Roman, celebrant, penitents, genua, prostration, private prayer, suppliants, Mass, Oremus, newadvent.

Defination from the web:
... 31) goes so far as to maintain that a kneeling posture is necessary. ... It must be said kneeling, except when illness makes the doing so physically impossible. ...