고령자의 앉기–일어서기 동작을 지원하는 시트 결합형 보행보조기기의 개발 및 평가

Abstract

Maintaining mobility is a crucial determinant of quality of life in older adults. However, due to the aging process, the functions of skeletal muscle and neuromuscular tissues begin to decline, leading to a loss of strength, balance, and reaction time. Based on the Korean National Anthropometric Data for males aged 70–84 years, the body weight was assigned to be 655.3 N. Linear static finite element analysis (FEA) was performed under quasi-static sagittal conditions. Posture angles were analyzed from 0° to 90° in 10° increments. The frame was modeled in structural steel, whereas the arm support and seat were modeled using polypropylene. A load-sharing model among the arm support (A), seat (S), and lower limbs (L) was applied with parameters Amin = 0.05, Amax = 0.40, Lmax = 0.60, and  = 1.3. Total deformation and equivalent von Mises stress were computed at each angle. The walker’s maximum total deformation occurred at  = 0° (0.244 mm), while the peak equivalent stress was 23.9 MPa, which remained below the structural failure threshold. The arm support exhibited higher deformation and stress in the initial rising phase (maximum deformation = 0.111 mm), which decreased as weight shifted to the lower limbs. The seat showed the highest stress in the sitting position (0.620 MPa), which rapidly diminished toward full standing, indicating effective offloading. A transient increase in deformation was observed between 60° and 70°, but it did not compromise structural safety. The proposed device maintained structural integrity throughout the sit-to-stand (STS) transition. By formalizing arm–seat–lower-limb load sharing as design variables, this study establishes an engineering basis and verification framework for STS-assistive walkers. Future work will involve dynamic analyses and clinical validation to further assess usability and fall-prevention benefits