title: Activities of everyday life with high spinal loads.
abstract: Activities with high spinal loads should be avoided by patients with back problems. Awareness about these activities and knowledge of the associated loads are important for the proper design and pre-clinical testing of spinal implants. The loads on an instrumented vertebral body replacement have been telemetrically measured for approximately 1000 combinations of activities and parameters in 5 patients over a period up to 65 months postoperatively. A database containing, among others, extreme values for load components in more than 13,500 datasets was searched for 10 activities that cause the highest resultant force, bending moment, torsional moment, or shear force in an anatomical direction. The following activities caused high resultant forces: lifting a weight from the ground, forward elevation of straight arms with a weight in hands, moving a weight laterally in front of the body with hanging arms, changing the body position, staircase walking, tying shoes, and upper body flexion. All activities have in common that the center of mass of the upper body was moved anteriorly. Forces up to 1650 N were measured for these activities of daily life. However, there was a large intra- and inter-individual variation in the implant loads for the various activities depending on how exercises were performed. Measured shear forces were usually higher in the posterior direction than in the anterior direction. Activities with high resultant forces usually caused high values of other load components.
authors.affiliation: Julius Wolff Institute, Charitè - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Antonius
authors.initials: A
authors.lastname: Rohlmann
authors.affiliation: Julius Wolff Institute, Charitè - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Pohl
authors.affiliation: Julius Wolff Institute, Charitè - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Alwina
authors.initials: A
authors.lastname: Bender
authors.affiliation: Julius Wolff Institute, Charitè - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Friedmar
authors.initials: F
authors.lastname: Graichen
authors.affiliation: Julius Wolff Institute, Charitè - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Jörn
authors.initials: J
authors.lastname: Dymke
authors.affiliation: Julius Wolff Institute, Charitè - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schmidt
authors.affiliation: Julius Wolff Institute, Charitè - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Bergmann
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D005593:Fracture Fixation, Internal; D050815:Fractures, Compression / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008159:Lumbar Vertebrae / Q000293:injuries* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016103:Spinal Fractures / Q000503:physiopathology* / Q000601:surgery; D013686:Telemetry; D016138:Walking / Q000502:physiology; D016474:Weight-Bearing