Hiroaki KOZUKA・Hiroshi TACHIYA: Skill-Assist Arm Using Passive Joints to Aid Spatial Movement of Human Limbs: IEEE Robotics and Automation Letters, JANUARY 2025, Volume10,Issue1, p.303-310, ISSN: 2377-3766,Online ISSN: 2377-3766, DOI: 10.1109/LRA.2024.3504291