Why is my plant held up by a clamp stand?

My Amaryllis is in flower and very top heavy. The flowers are not evenly distributed around the stem and the stem is not straight. A force (weight) x distance from the pot means that there is a torque twisting the plant which means that it keeps falling over. The clamp provides an equal and opposite torque, meaning that the resultant torque is zero and the plant stays upright.