The aging of Korea is rapidly advancing in an unprecedented rate in the world. Indoor and outdoor safety accidents involving the elderly frequently occur, with elderly population increasing. Because the physical strength of elderly is decreased, it is necessary to develop devices that aid the everyday life of the elderly to prevent safety accidents. Among many activities, the motions of standing from and sitting on a chair require much physical strength from particular body parts, which causes an overload for particular body parts. To the elderly the repeating motion of standing from and sitting down on a chair is burdensome, because they do not have enough physical strength compare to young persons . As a result the elderly could be injured or falling during standing or sitting. Therefore, the development of a lift chair that considers the problems mentioned above is necessary to prevent the safety accidents of the elderly. The study designed a non-motorized lift chair that comfortably aids the standing and sitting down motion for the use of the elderly by reflecting the anthropometric data of the Korean elderly over 65 years old. Also the design was implemented to smoothly aid the standing motion by considering the knee angle of the elderly when standing. Because the regained strength to stand from a chair is depend on the knee angle. Unlike existing lift devices, this device utilizes a tilting mechanism that does not use electric power so that the product could be composed inexpensively than existing chairs released in the market.

With the increase in elderly population rate, interest in development of equipment to aid for the elderly activities has been increased. Since the physical features of repetitive behavior of elderly people standing and sitting can cause the stress on certain parts of the body, The necessity of developing Lift Chair concerning the foregoing problem has been to the fore. In this study, we set the average body size of the elderly aiming to develop non-motorized Lift Chair, developed Non-motorized tilting mechanism based on the Muscle strength change at knee angle, and did a study relatively inexpensive Lift Chair considering esthetic and practicality.