title: Generation of physiological parameter sets for hip joint motions and loads during daily life activities for application in wear simulators of the artificial hip joint.
abstract: At present, wear investigations of total hip replacements are performed in accordance with the ISO standard 14242, which is based on simplified kinematic and force data of the gait cycle. The aim of this analytical study was to generate parameter sets of daily life activities in order to replicate more realistic joint load situations in wear testing. Hence, published in vivo motion and force data of daily life activities were evaluated and adjusted using analytical techniques. The created kinematically and dynamically consistent parameter sets comprised time trajectories of three Cardan angles to describe the motion of the femur with respect to the pelvis and time trajectories of three force components, representing the hip joint contact force. The parameter sets include the activities of walking, knee bending, stair climbing and a combined load case of sitting down and standing up. Additionally, a motion sequence following the frequency of daily life activities was presented. Differences of the evaluated angular motions and joint contact forces in comparison to the ISO standard 14242-1 were pointed out. The results of this study offer the possibility to extend the kinematics and dynamics of the ISO standard test protocol and to support the loading conditions of hip wear simulators with a comprehensive set of motions and loads close to reality.
authors.affiliation: Biomechanics and Implant Technology Research Laboratory, Department of Orthopaedics, University Medicine Rostock, D-18057 Rostock, Germany. christian.fabry@med.uni-rostock.de
authors.forename: Christian
authors.initials: C
authors.lastname: Fabry
authors.forename: Sven
authors.initials: S
authors.lastname: Herrmann
authors.forename: Michael
authors.initials: M
authors.lastname: Kaehler
authors.forename: Ernst-Dieter
authors.initials: ED
authors.lastname: Klinkenberg
authors.forename: Christoph
authors.initials: C
authors.lastname: Woernle
authors.forename: Rainer
authors.initials: R
authors.lastname: Bader
mesh_terms: D000203:Activities of Daily Living; D001696:Biomechanical Phenomena; D006621:Hip Joint / Q000502:physiology*; D008422:Materials Testing; D008962:Models, Theoretical; D009068:Movement; D011187:Posture; D019736:Prostheses and Implants; D016474:Weight-Bearing