The most important consideration when choosing a wheelchair is the size of the wheelchair. The main parts of the wheelchair-bearing body are around the ischial ischial tuberosity, around the femur, around the armpits and around the shoulder blades.The size of the wheelchair, especially the width of the seat, the depth of the seat and the height of the backrest, and the distance from the pedal to the seat cushion, will cause the occupant to be affected by the blood circulation of the affected part, and skin abrasion and even pressure sores may occur. In addition, consider the patient’s safety, handling ability, weight of the wheelchair, location of use, appearance and other issues.