# Current Status and Consideration of Support/Care Robots for Stand-Up Motion
## 1 Introduction  
Japan is the most advanced country in terms of aging. As of 2015, the aging rate in developed countries was 26.6%, in Korea it was 13.1%, in the United States it was 14.8%, and in Sweden it was 19.9%. By 2060, it is estimated that about 1 out of 2.5 people in Japan will be aged 65 years or older [1]. Against this background, it is anticipated that an increase in the number of people requiring care and a shortage of human resources for caregivers will become more apparent in the future. The Ministry of Economy, Trade, and Industry (METI) and the Ministry of Health, Labour, and Welfare (MHLW) are concentrating their efforts on the field of caregiving and promoting efforts to develop and support the introduction of robotic care devices [2]. From these, an active push for the introduction of \"robot\" technology in the field of nursing, medical treatment, and welfare has been carried out in our country. On the other hand, [PERSON] [3] describes that there is a current situation in which rehabilitation robots have not yet come to practical use in the field from the viewpoint of a physiotherapist who belongs to the technology development headquarters of an enterprise. There are many issues that need to be examined concretely, such as factors that prevent practical application. One way to solve this situation is to consider what kind of robots have been introduced to date and to grasp what common problems and needs exist from the clinic side and the development side. As of 2020, many robots have already been developed and reported both domestically and internationally, various problems concerning their practical application in the clinical field have been found, solutions have been proposed, and the verifications of these solutions have been carried out. Some of these have extended robots' use to aiding people instanding up (sit-to-stand: STSs) and subsequent movements. Robots assisting with STS have been reported from various viewpoints, such as their mechanisms and control systems, in order to respond to social demands corresponding to each object illness, etc. However, robots such as Welwalk [4] and HAL(r) [5], which are increasingly being used at domestic rehabilitation sites and are beginning to be recognized, are but the tip of the iceberg, and a number of robots that are not yet widely known have been studied and reported. This paper covers domestic and overseas previous research papers on STS assistance robots. STS is an essential movement for daily life and has clinical significance: STS is an essential movement for transitioning from sitting to standing posture, and higher STS movement ability has been reported to enhance the quality of life [6]. The clinical implications of STS are that daily STS can maintain hip and knee strength [7], that STS performance in the general elderly population and in people with who have suffered cerebrovascular accidents (CVAs) correlates with future mobility-related movements and fall rates [8; 9], and that intensive STS training in people who have suffered CVAs is beneficial for learning mobility skills as well as increasing the loading rate on the paralyzed lower limb [10]. From the above, STS is a prerequisite movement for walking, has similarities with walking, and is a necessary movement for improving QOL. As a clinical effect of these STS assistance robots, [PERSON] et al. [11] reported that a patient with complete paraplegia due to 10 th-11 th thoracic spinal cord injury was able to achieve STS with visual feedback and balance control through the use of HAL-5. [PERSON] et al. [12] reported that the use of a linearly driven STS training system in patients with after-effect of CVA increased the loading rate of the paralyzed leg during STS. These reports suggest that an STS assistance robot can compensate for a deficit or decrease in physical functions and may allow patients with STS difficulties to perform STS.