title: [Jamming a child's finger: an experimental study to determine elastic resistance and the point of onset of bone/joint deformation].
abstract: Knowledge of the elastic properties of children's fingers is very important to understand the potential hazard for jamming injuries that exists in modern motor vehicles with automatic power-operated windows. This study determined the elastic resistance and the point of onset of bone/joint deformation at each of 5 different jam positions of a child's finger under continuous dorsal-palmar compression. An unembalmed finger that recently had been surgically removed from a polydactylic 8 month-old girl was jammed in a custom hydraulic test apparatus. A subminiature force sensor and an electrometric path sensor measured force and deflection values. To visualise the respective point of onset of bone/joint deformation, jamming of the finger was performed under fluoroscopy. The mean force at the point of onset of bone/joint deformation was 78.4 N. The current statutory limit of 100 N for the maximum closing force of an automatic power-operated motor vehicle window is thus well beyond the point at which finger injuries can occur in children. Assuming finger injuries in children can occur at a jamming force below approximately 80 N, a reduction of the statutory limit to us higher than 50 N is reasonable.
authors.affiliation: Rhön Klinikum AG, Klinik für Handchirurgie, Bad Neustadt Saale. Bad Neustadt Saalebernd.hohendorff @hotmail.com
authors.forename: B
authors.initials: B
authors.lastname: Hohendorff
authors.forename: C
authors.initials: C
authors.lastname: Weidermann
authors.forename: P
authors.initials: P
authors.lastname: Pollinger
authors.forename: K
authors.initials: K
authors.lastname: Burkhart
authors.forename: K-J
authors.initials: KJ
authors.lastname: Prommersberger
authors.forename: L P
authors.initials: LP
authors.lastname: Müller
mesh_terms: D001696:Biomechanical Phenomena; D004548:Elasticity; D005260:Female; D005383:Finger Injuries / Q000503:physiopathology*; D005384:Finger Joint / Q000503:physiopathology*; D050278:Finger Phalanges / Q000293:injuries* / Q000503:physiopathology*; D005471:Fluoroscopy; D006801:Humans; D007223:Infant; D009262:Nails / Q000293:injuries / Q000503:physiopathology; D017695:Soft Tissue Injuries / Q000503:physiopathology*