[Risk of injury to children's fingers in power-operated motor vehicle windows]. / Verletzungsrisiko von Kinderfingern in automatischen Scheibenschliessanlagen von Kraftfahrzeugen.

BACKGROUND: This study examines the dimensions of children's fingers and the risk of jam injuries in a 4-mm gap between glass and gasket of power-operated motor vehicle windows. MATERIAL AND METHODS: The diameter of the proximal, middle, and distal phalanx and of the proximal and distal interphalangeal joint of each finger of the right hand of 160 children was measured in a cross-sectional investigation. Six different drawings in cross section of gaskets and glass window panes of current motor vehicle side door windows at a vertical gap of 4 mm were drawn in correct proportion. The larger actual width of the oblique gap between window glass and gasket was measured and related to the diameters of children's fingers. RESULTS: Almost all fingers and joints fit in the largest actual gap of 18 mm between glass and gasket of one seal design. CONCLUSION: The European guideline 74/60/EWG specifications currently pertaining to closing force restriction do not eliminate the risk of potentially serious injury to children's fingers in motor vehicle power windows.

[Jamming a child's finger: an experimental study to determine elastic resistance and the point of onset of bone/joint deformation]. / Einklemmung eines Kinderfingers: Eine experimentelle Studie zur Bestimmung der elastischen Widerstände und der Punkte des Beginns der Knochen-/Gelenkdeformierung.

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.

Finger injuries caused by power-operated windows of motor vehicles: an experimental cadaver study.

The aim of this experimental cadaver study was to investigate which kinds of lesions could occur in jam events between the glass and seal entry of power-operated motor vehicle side door windows at two different closing forces. Ten hands of fresh cadaver specimens were used. Three different hand positions chosen to simulate real events in which a finger is jammed between the glass and seal entry of the window of a current motor vehicle were examined. The index, middle, ring, and little finger of each hand were separately jammed both at the proximal and distal interphalangeal joint at closing forces of 300 and 500 N with a constant window glass closing speed of 10 cm/s. Macroscopically visible injuries were documented and radiographs of all fingers were obtained in two standard planes. At a closing force of 300 N, contusion marks of the skin, palmar joint instabilities and superficial skin lesions occurred, whilst at 500 N superficial skin lesions, superficial and deep open crush injuries, and fractures were observed. The results of this study experimentally demonstrate the kinds of finger injuries that could be expected in real jam events between the glass and seal entry in automatic power-operated windows.

Entrapment of adult fingers between window glass and seal entry of a motor vehicle side door: an experimental study for investigation of the force at the subjective pain threshold.

In modern motor vehicles with automatic power windows, a potential hazard exists for jam events of fingers between the window glass and seal entry. This study determined entrapment forces acting on adult fingers at the subjective maximum pain threshold during entrapment in such windows. The length and the girth of the proximal and distal interphalangeal joints of the triphalangeal fingers of the right hands of 109 participants (60 men, 49 women) were measured; the diameter was calculated from girth, which was assumed to be circular. The automatic power window system of a motor vehicle side door was changed to a mechanical system. During entrapment the force distributed across the four proximal interphalangeal joints (PIPs), and separately on the proximal interphalangeal (iPIP) and then the distal interphalangeal (iDIP) joints of the index finger was measured using a customized force sensor. The maximum bearable entrapment force was 97.2 ± 51.8 N for the PIPs, 43.4 ± 19.9 N for the iPIP, and 36.9 ± 17.8 N for the iDIP. The positive correlation between finger diameter and maximum entrapment force was significant. Particularly with regard to the risk to children's fingers, the 100 N statutory boundary value for closing force of electronic power windows should be reduced.

Lengths, girths, and diameters of children's fingers from 3 to 10 years of age.

We obtained data on the lengths, girths, and diameters of the fingers of children from 3 to 10 years of age. A total of 160 children (78 girls, 82 boys) were examined in a cross-sectional investigation. The length of each finger of the right hand of every child was measured, as were the girths of the proximal, middle, and distal phalanges, and of the proximal and distal interphalangeal joint. The average length of the thumb was 49 (35-65) mm. The index and ring fingers both averaged 69 (index, 50-88; ring, 42-96) mm in length, while the middle and little fingers averaged 72 (57-100) and 56 (40-74) mm, respectively. Average diameter, calculated from the girth measurement, was 16 (11-22) mm for the thumb, 15 mm for both the index (9-22) and middle (10-21) fingers, 14 (10-20) and 13 (8-19) mm for the ring and little fingers, respectively. The average length of each finger increased by 37% from 3 to 10 years of age, average girth by 24%, and diameter increased by 20%. We observed no differences in length, girth, and diameter between the sexes. The dimensions of children's fingers are relevant to injuries from automatic, power-operated window lifters of motor vehicles because risk of injury to a finger jammed between an ascending window and the seal entry depends upon the diameter of the finger. Additionally, short fingers of young children can be jammed over almost their entire length in the oblique design of a car window seal entry.