title: Synthesis of standing-up trajectories using dynamic optimization.
abstract: Dynamic optimization as a tool to compute standing-up trajectories was investigated. Sit-to-stand manoeuvres in five intact persons and five trans-femoral amputees were measured. Movements and ground reaction forces acting on the body were recorded. A five-segment 3D dynamic model of standing-up was developed. In each particular subject, the optimization criterion which yielded trajectories that best resemble the measured standing-up movement was determined. Since the intact persons used considerably different criteria in choosing the standing-up trajectories than the amputees, the optimal trajectories were computed by minimizing cost functionals (CF) with distinctive structures for each group of individuals. In intact persons, a unique cost functional was found which yielded realistic standing-up manoeuvres. In amputees, subject-specific sets of parameters indicating slightly different preferences in optimizing the effort of particular muscle groups were used.
authors.affiliation: Laboratory of Biomedical Engineering and Robotics, Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, 1000 Ljubljana, Slovenia. jernej.kuzelicki@robo.fe.uni-lj.si
authors.forename: Jernej
authors.initials: J
authors.lastname: Kuzelicki
authors.forename: Milos
authors.initials: M
authors.lastname: Zefran
authors.forename: Helena
authors.initials: H
authors.lastname: Burger
authors.forename: Tadej
authors.initials: T
authors.lastname: Bajd
mesh_terms: D000328:Adult; D000671:Amputation, Surgical / Q000534:rehabilitation*; D000674:Amputees; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D005269:Femur / Q000601:surgery*; D006801:Humans; D008297:Male; D008954:Models, Biological; D009068:Movement / Q000502:physiology*; D011187:Posture; D012016:Reference Values; D012494:Sampling Studies; D012680:Sensitivity and Specificity