title: Jamming of fingers: an experimental study to determine force and deflection in participants and human cadaver specimens for development of a new bionic test device for validation of power-operated motor vehicle side door windows.
abstract: The deformability of human fingers is central to addressing the real-life hazard of finger jamming between the window and seal entry of a power-operated motor vehicle side door window. The index and little fingers of the left hand of 109 participants and of 20 cadaver specimens were placed in a measurement setup. Participants progressively jammed their fingers at five different dorsal-palmar jam positions up to the maximum tolerable pain threshold, whereas the cadaver specimens were jammed up to the maximum possible deflection. Force-deflection curves were calculated corresponding to increasing deflection of the compressed tissue layers of the fingers. The average maximum force applied by the participants was 42 N to the index finger and 35 N to the little finger. In the cadaver fingers, the average of the maximum force applied was 1886 N for the index finger and 1833 N for the little finger. In 200 jam positions, 25 fractures were observed on radiographs; fractures occurred at an average force of 1485 N. These data assisted the development of a prototype of a bionic test device for more realistic validation of power-operated motor vehicle windows.
authors: Elbe Clinic Stade Buxtehude, Department of Handsurgery, Aesthetics and Plastic Surgery, Stade, Germany. bernd. hohendorff@hotmail.com
authors: Bernd
authors: B
authors: Hohendorff
authors: Christian
authors: C
authors: Weidermann
authors: Philipp
authors: P
authors: Pollinger
authors: Klaus J
authors: KJ
authors: Burkhart
authors: Lars Peter
authors: LP
authors: Müller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001701:Bionics / Q000295:instrumentation* / Q000379:methods; D002102:Cadaver; D055119:Elastic Modulus; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D005383:Finger Injuries / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D006244:Hardness; D006245:Hardness Tests / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D018986:Motor Vehicles; D018570:Risk Assessment; D013314:Stress, Mechanical; D014949:Wounds, Nonpenetrating / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*