The machine is designed to evaluate the ability of the chair to withstand stresses that occur because of repetitive loading that can be imposed on the armrest structure. Loading of this type is the result of using the armrests as a support when getting into or out of the chair. During the test, machine will simultaneously apply a force of 400N to each arm initially at 10°±1°angle, and the seat keep restrained from rotation movement, then continue constantly load the force on arm for 10 000-60,000 cycles at a rate between 10 and 30cycles per minute.