One can always go to a hardware or garden store and purchase a small foam-cushioned kneeler.
Of course, one can always also offer up the struggle, pain and effort of getting on and off one's knees to Jesus, who certainly suffered for us. What joy to unite even the tiniest bit of our earthly pains and sufferings with His holy Passion!
Immaculate Heart of Mary, triumph soon!
Most Sacred Heart of Jesus, have mercy on us.