The back is made so that it can be adjusted to the width of the back of the person using the tricycle or bicycle. It is comfortable, finished with soft upholstery. Velcro fastener is very strong. Holding the torso with the straps provides a simple sitting position. The backrest prevents slipping from the seat while balancing. This gives more stability to people with hemiplegia, MS or similar dysfunctions of the motor organs. Those who are unsure and afraid of height will feel more secure.