title: Evaluation of ischial weight-bearing orthoses, based on in-vivo hip joint force measurements.
abstract: The reduction of hip joint forces by ischial weight-bearing orthoses, used for the treatment of Legg-Perthes and other joint diseases, was measured in vivo in a patient with two instrumented endoprostheses. Three different types of orthoses reduced hip joint loading by about 30%, independent of their cuff design and the position in which the femur was held. The direction of the joint forces was changed in such a way that the size of the load-carrying joint areas decreased by up to 3.4% with two conventional orthoses. With the third model with improved containment of the femoral head this area increased by up to 8.2%. All the orthoses studied support the pelvis too close to the affected joint, leading to insufficient load reduction. A design concept is proposed which prevents tilting of the pelvis in the frontal plane and may improve the force reduction at the hip joint.
authors.affiliation: Oskar-Helene-Heim, Biomechanics Laboratory, Orthopaedic Hospital of the Free University, Berlin, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Bergmann
authors.forename: M
authors.initials: M
authors.lastname: Correa da Silva
authors.forename: G
authors.initials: G
authors.lastname: Neff
authors.forename: A
authors.initials: A
authors.lastname: Rohlmann
authors.forename: F
authors.initials: F
authors.lastname: Graichen