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Lethal pedestrian – Passenger car collisions in Berlin
Legal Medicine 11 (2009) S324–S326
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Legal Medicine journal homepage: www.elsevier.com/locate/legalmed
Lethal pedestrian – Passenger car collisions in Berlin Changed injury patterns in two different time intervals Edwin Ehrlich a,*, Anja Tischer b, H. Maxeiner b a b
State Institute of Legal and Social Medicine, Turmstrasse 21, Haus L, 10559 Berlin, Germany Charité Berlin, Department of Legal Medicine, Turmstrasse 21, Haus L, 10559 Berlin, Germany
a r t i c l e
i n f o
Article history: Received 19 December 2008 Accepted 8 January 2009 Available online 3 March 2009 Keywords: Traffic accident Pedestrian Frontal collision Injuries Passive safety of automobiles
a b s t r a c t To expand the passive safety of automobiles protecting traffic participants technological innovations were done in the last decades. Objective of our retrospective analysis was to examine if these technical modifications led to a clearly changed pattern of injuries of pedestrians whose death was caused by the accidents. Another reduction concerns the exclusion of injured car passengers – only pedestrians walking or standing at the moment of collision were included. We selected time intervals 1975–1985 and 1991–2004 (=years of construction of the involved passenger cars). The cars were classified depending on their frontal construction in types as presented by Schindler et al. [Schindler V, Kühn M, Weber S, Siegler H, Heinrich T. Verletzungsmechanismen und Wirkabschätzungen der Fahrzegfrontgestaltung bei Pkw-Fußgänger-Kollisionen. Abschlußbericht im Auftrag der Deutschen Versicherungswirtschaft e.V. TU-Berlin Fachgebiet Kraftfahrzeuge (GDV) 2004:36–40]. In both periods more than 90% of all cars were from the usual types small/medium/large class. Hundred and thirty-four autopsy records of such cases from Department of Forensic Medicine (Charité Berlin) data were analysed. The data included technical information of the accidents and vehicles and the external and internal injuries of the victims. The comparison of the two periods showed a decrease of serious head injuries and femoral fractures but an increase of chest-, abdominal and pelvic injuries. This situation could be explained by an increased occurrence of soft-face-constructions and changed front design of modern passenger cars, resulting in a favourable effects concerning head impact to the car during accident. Otherwise the same kinetic energy was transferred to the (complete) victim – but because of a displacement of main focus of impact the pattern of injuries modified (went distally). Ó 2009 Elsevier Ireland Ltd. All rights reserved.
1. Introduction The density of road traffic continuously increases since decades. However, the number of persons killed by traffic accidents (in Germany) decreases since many years. Explanations for this inverse situation include technical improvements concerning active as well as passive accident-equipments of cars, predominantly protecting the occupants [1–3]. Manufacturers of passenger cars additionally comprise security aspects of pedestrians in their technical development; pedestrians are the mostly affected group of accident victims, and are comparatively unprotected. A predominant factor concerning this aspect is optimising the frontal form of modern passenger cars: round, even and yielding hoods and adjoining parts of the fenders and other frontal parts, increase of the angle of inclination of the wind-screen.
* Corresponding author. Tel.: +49 30 901728 100; fax: +49 30 901728 153. E-mail address: [email protected] (E. Ehrlich). 1344-6223/$ - see front matter Ó 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.legalmed.2009.01.017
Interested in the question if such technical improvement had effects on the ‘‘result” of car-pedestrian accidents, we analysed the spectrum of injuries in pedestrians killed and compared the actual injury pattern with the pattern found in accidents 10–20 years ago.
2. Materials and methods Basis of our study were the autopsy protocols including parts of the records of the judicial inquiries (group A: 1978–1985 and group B: 1991–2004) of the Department of Legal Medicine, University Medicine of Berlin (CBF). Element resulting in integration in these phases was the year of construction/model of the car. We included only accidents occurred inside the town (highway accidents excluded), in which a car frontally hit the pedestrian in its upright position (usually walking). The two accident collectives consisted of 74 ‘‘old” and 60 ‘‘new’ vehicles. The frontal car geometry was classified in types presented in the technical literature [4]: sports
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E. Ehrlich et al. / Legal Medicine 11 (2009) S324–S326
car, micro compact, micro van, mini van, small – medium – upper class, cross-country vehicle. Because of their minimal participation accidents with sports cars and cross-country vehicle were omitted; all van classes as well as micro compacts were not present in our material. The impact velocities were subdivided into the classes <30; 30–50; and >50 km/h. External and internal injuries of all body regions were registered (present/not present) and classified using the ‘‘abbreviated injury Scale, 1990 revision” (AIS90) and translating this score into a scale between 1 and 5 (Association for the advancement of automotive medicine), reflecting the anatomical severity of each injury. To obtain a ‘‘complete” injury severity case by case we added the squares of the three highest AIS90-values. Victims were 72 women (16–91 years old; median: 69) and 62 men (20–95 years; median: 60); the age distribution in both intervals was similar, with a majority of persons older than 65 years (A: 59%, respectively, B: 60%). The comparison of injury types was restricted to collisions speeds which were observed frequently enough (30–50 km/h).
ans in both periods (A: 34%, B: 33%; Fig. 2), but here clinically insignificant (external) head injuries are included. If only serious (life threatening) head injuries were considered, a decrease was obvious. 4. Discussion Systematic forensic studies similar to our exist, but have been made ca. 10 years ago [5,6]. Actually we found different injury spectrums (and a few other points) in pedestrians killed by (frontal) car collisions recently, respectively, 10–20 years ago. The decrease of deaths with longer survival time in the recent period B most likely is caused by a better rescue system as well as better medical/intensive care treatment in Berlin. To our interpretation the modification of the construction of the frontal parts of the passenger cars is also an important factor influencing the sustained injury types. However, the most dominant factor is and probably remains the collision speed. Depending from our material, only medium collision speeds were included in our series; this situation might be typical for accidents inside towns. In low speed accident, lethal injuries usually are seldom (7 cases in our material) and often additionally caused by previous severe illness or non-direct injury complications. Our material indicates a decrease of serious head- and lowerlimb-injuries in the recent period B, interpreted as a result of changes in vehicle construction: ‘‘soft-face”, round frontal form, better ability of deformation – resulting in less impact severity for the mostly unavoidable head contact to the car. Additionally these alterations could reduce the injury severity of hit pedestrians: drawing the posterior margin of the hood over the frontal traverse, the lower part of the wind-screen and the wind-screen wiper [2]. Furthermore in modern cars because of the form of the frontal margin of the hood (in adults) the upper segment of an impacted lower leg will be supported, reducing a significant bending [1]. In the ‘‘newer period” B an increase of chest-, abdominal and pelvic injuries in killed pedestrians was present – perhaps a negative consequence of this construction modification of the front, resulting in a main impact rising – from the lower leg to the center of body mass. The decrease of leg bending could be the cause for ‘‘harder” pelvic
3. Results Inside Berlin the typical car – pedestrian – collision with a killed pedestrian (our material: 64 cases) involved medium-class cars and happened in the collision speed range 30–50 km/h; lower as well as higher speeds were distinctly less frequent. Death at the scene was not infrequent (A: 18%; B: 22%). The rate: survival time until 24 h/longer in group B was also higher than in A. Causes of death in the two periods differed: head injury decreased from 35% to 27% but polytrauma cases increased from 15% to 37% (Fig. 1). Comparing the injury types a distinct improvement could be found in accidents with small-class cars: pelvic fractures occurred more frequent while in contrast relevant injuries of head, neck, chest and the legs decreased (comparison for all cases see Fig. 2). Pedestrians injured by medium-class and high-class cars in period B sustained less frequently skull fractures, significant intracranial haemorrhages, cervical and femoral fractures than in period A – but an increase of rib and pelvic fractures as well as intraabdominal injuries. At first sight, the injury combination head–chest–lower-limb was the most frequent in killed pedestri-
Causes of death 1978-85
Percent
30%
1991-2004 37%
35%
27% 20%
23%
15%
10%
15% 8%
3%
1%
12%
10%
8%
7%
0% 1
2
3
4
5
6
7
1
Cause of death
2
3
4
5
6
7
Cause of death
1 Head 2 Polytrauma 3 Haemorrhag. shock 4 Head destruction 5 Pneumonia 6 Pulmonary thrombembolism 7 Others Fig. 1. Causes of death.
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E. Ehrlich et al. / Legal Medicine 11 (2009) S324–S326
Injury combinations
Body regions
1978-85 6-0-0 5-6-0 5-0-0 4-5-6 3-6-0 3-5-6 3-4-5 3-0-0 1-6-0 1-5-6 1-5-0 1-4-5 1-3-6 1-3-5 1-3-4 1-2-5 1-0-0 0-0-0
1991-2004
8%
12%
19%
34%
33% 13%
0%
10%
20%
30%
0%
10%
Percent
20%
30%
Perzent
Combinations of the 3 most injured regions 1 Head / neck 2 Face 5 Pelvis/lower leg
3 Chest 4 Abdomen 6 Body surface
Fig. 2. Combinations of most severely injured regions.
impacts as well as higher impact speeds of the upon laded upper part of the body [1]. The frequency of lower leg fractures in both periods was similar. Lower positioned bumpers obviously spare the knee region and reduce not the frequency, but the severity of lower leg fractures if they are (non-prominently) integrated in the front of the car [7]. 5. Conclusion A comparison of the injury patterns in pedestrians killed in traffic accidents by impacts of passenger cars, build in two different periods (‘‘older” and ‘‘new”) – with alterations of their frontal form – yielded a shifting of the predominant injury focus from the upper (head) to the medium (chest, abdomen, pelvis) body region and a reduction of the frequency of femoral fractures. Conflict of interest None.
References [1] Friesen F, Wallentowitz H, Philipps M. Optimierte Fahrzeugfront hinsichtlich des Fußgängerschutzes. Berichte der Bundesanstalt für Straßenwesen: Fahrzeugtechnik. Heft 2001;F38:44 S. [2] Glaeser K-P. Der Anprall des Kopfes auf die Fronthaube von Pkw beim Fußgängerunfall. Berichte der Bundesanstalt für Straßenwesen: Fahrzeugtechnik. Heft 1996;F14:100 S. [3] Mattern R. Veränderte Verletzungsmuster durch neue Kfz-Sicherheitsstandards anhand aktueller Unfallabläufe. Vortrag anlässlich der 60. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie 1996:4 S. [4] Schindler V, Kühn M, Weber S, Siegler H, Heinrich T. Verletzungsmechanismen und Wirkabschätzungen der Fahrzegfrontgestaltung bei Pkw-FußgängerKollisionen. Abschlußbericht im Auftrag der Deutschen Versicherungswirtschaft e.V. TU-Berlin Fachgebiet Kraftfahrzeuge (GDV) 2004:36–40. [5] Bockholdt B. Tödliche Fußgänger-Pkw-Kollisionen in beiden Teilen Berlins 1980–1990. Med Diss 1995:50S. [6] Ettemeyer M. Untersuchung tödlicher Fußgänger-Pkw-Unfälle hinsichtlich der Auswirkungen der Fahrzeugfront auf das Verletzungsmuster der betroffenen Fußgänger. Med Diss 1991:46 S. [7] Otte D, Pohlemann T. Analyse und Bewertung des Sekundäraufpralles auf die Straße bei Pkw-Fußgänger-Kollisionsabläufen. Verkehrsunfall und Fahrzeugtechnik 2002;10:261–7.
Contents lists available at ScienceDirect
Legal Medicine journal homepage: www.elsevier.com/locate/legalmed
Lethal pedestrian – Passenger car collisions in Berlin Changed injury patterns in two different time intervals Edwin Ehrlich a,*, Anja Tischer b, H. Maxeiner b a b
State Institute of Legal and Social Medicine, Turmstrasse 21, Haus L, 10559 Berlin, Germany Charité Berlin, Department of Legal Medicine, Turmstrasse 21, Haus L, 10559 Berlin, Germany
a r t i c l e
i n f o
Article history: Received 19 December 2008 Accepted 8 January 2009 Available online 3 March 2009 Keywords: Traffic accident Pedestrian Frontal collision Injuries Passive safety of automobiles
a b s t r a c t To expand the passive safety of automobiles protecting traffic participants technological innovations were done in the last decades. Objective of our retrospective analysis was to examine if these technical modifications led to a clearly changed pattern of injuries of pedestrians whose death was caused by the accidents. Another reduction concerns the exclusion of injured car passengers – only pedestrians walking or standing at the moment of collision were included. We selected time intervals 1975–1985 and 1991–2004 (=years of construction of the involved passenger cars). The cars were classified depending on their frontal construction in types as presented by Schindler et al. [Schindler V, Kühn M, Weber S, Siegler H, Heinrich T. Verletzungsmechanismen und Wirkabschätzungen der Fahrzegfrontgestaltung bei Pkw-Fußgänger-Kollisionen. Abschlußbericht im Auftrag der Deutschen Versicherungswirtschaft e.V. TU-Berlin Fachgebiet Kraftfahrzeuge (GDV) 2004:36–40]. In both periods more than 90% of all cars were from the usual types small/medium/large class. Hundred and thirty-four autopsy records of such cases from Department of Forensic Medicine (Charité Berlin) data were analysed. The data included technical information of the accidents and vehicles and the external and internal injuries of the victims. The comparison of the two periods showed a decrease of serious head injuries and femoral fractures but an increase of chest-, abdominal and pelvic injuries. This situation could be explained by an increased occurrence of soft-face-constructions and changed front design of modern passenger cars, resulting in a favourable effects concerning head impact to the car during accident. Otherwise the same kinetic energy was transferred to the (complete) victim – but because of a displacement of main focus of impact the pattern of injuries modified (went distally). Ó 2009 Elsevier Ireland Ltd. All rights reserved.
1. Introduction The density of road traffic continuously increases since decades. However, the number of persons killed by traffic accidents (in Germany) decreases since many years. Explanations for this inverse situation include technical improvements concerning active as well as passive accident-equipments of cars, predominantly protecting the occupants [1–3]. Manufacturers of passenger cars additionally comprise security aspects of pedestrians in their technical development; pedestrians are the mostly affected group of accident victims, and are comparatively unprotected. A predominant factor concerning this aspect is optimising the frontal form of modern passenger cars: round, even and yielding hoods and adjoining parts of the fenders and other frontal parts, increase of the angle of inclination of the wind-screen.
* Corresponding author. Tel.: +49 30 901728 100; fax: +49 30 901728 153. E-mail address: [email protected] (E. Ehrlich). 1344-6223/$ - see front matter Ó 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.legalmed.2009.01.017
Interested in the question if such technical improvement had effects on the ‘‘result” of car-pedestrian accidents, we analysed the spectrum of injuries in pedestrians killed and compared the actual injury pattern with the pattern found in accidents 10–20 years ago.
2. Materials and methods Basis of our study were the autopsy protocols including parts of the records of the judicial inquiries (group A: 1978–1985 and group B: 1991–2004) of the Department of Legal Medicine, University Medicine of Berlin (CBF). Element resulting in integration in these phases was the year of construction/model of the car. We included only accidents occurred inside the town (highway accidents excluded), in which a car frontally hit the pedestrian in its upright position (usually walking). The two accident collectives consisted of 74 ‘‘old” and 60 ‘‘new’ vehicles. The frontal car geometry was classified in types presented in the technical literature [4]: sports
S325
E. Ehrlich et al. / Legal Medicine 11 (2009) S324–S326
car, micro compact, micro van, mini van, small – medium – upper class, cross-country vehicle. Because of their minimal participation accidents with sports cars and cross-country vehicle were omitted; all van classes as well as micro compacts were not present in our material. The impact velocities were subdivided into the classes <30; 30–50; and >50 km/h. External and internal injuries of all body regions were registered (present/not present) and classified using the ‘‘abbreviated injury Scale, 1990 revision” (AIS90) and translating this score into a scale between 1 and 5 (Association for the advancement of automotive medicine), reflecting the anatomical severity of each injury. To obtain a ‘‘complete” injury severity case by case we added the squares of the three highest AIS90-values. Victims were 72 women (16–91 years old; median: 69) and 62 men (20–95 years; median: 60); the age distribution in both intervals was similar, with a majority of persons older than 65 years (A: 59%, respectively, B: 60%). The comparison of injury types was restricted to collisions speeds which were observed frequently enough (30–50 km/h).
ans in both periods (A: 34%, B: 33%; Fig. 2), but here clinically insignificant (external) head injuries are included. If only serious (life threatening) head injuries were considered, a decrease was obvious. 4. Discussion Systematic forensic studies similar to our exist, but have been made ca. 10 years ago [5,6]. Actually we found different injury spectrums (and a few other points) in pedestrians killed by (frontal) car collisions recently, respectively, 10–20 years ago. The decrease of deaths with longer survival time in the recent period B most likely is caused by a better rescue system as well as better medical/intensive care treatment in Berlin. To our interpretation the modification of the construction of the frontal parts of the passenger cars is also an important factor influencing the sustained injury types. However, the most dominant factor is and probably remains the collision speed. Depending from our material, only medium collision speeds were included in our series; this situation might be typical for accidents inside towns. In low speed accident, lethal injuries usually are seldom (7 cases in our material) and often additionally caused by previous severe illness or non-direct injury complications. Our material indicates a decrease of serious head- and lowerlimb-injuries in the recent period B, interpreted as a result of changes in vehicle construction: ‘‘soft-face”, round frontal form, better ability of deformation – resulting in less impact severity for the mostly unavoidable head contact to the car. Additionally these alterations could reduce the injury severity of hit pedestrians: drawing the posterior margin of the hood over the frontal traverse, the lower part of the wind-screen and the wind-screen wiper [2]. Furthermore in modern cars because of the form of the frontal margin of the hood (in adults) the upper segment of an impacted lower leg will be supported, reducing a significant bending [1]. In the ‘‘newer period” B an increase of chest-, abdominal and pelvic injuries in killed pedestrians was present – perhaps a negative consequence of this construction modification of the front, resulting in a main impact rising – from the lower leg to the center of body mass. The decrease of leg bending could be the cause for ‘‘harder” pelvic
3. Results Inside Berlin the typical car – pedestrian – collision with a killed pedestrian (our material: 64 cases) involved medium-class cars and happened in the collision speed range 30–50 km/h; lower as well as higher speeds were distinctly less frequent. Death at the scene was not infrequent (A: 18%; B: 22%). The rate: survival time until 24 h/longer in group B was also higher than in A. Causes of death in the two periods differed: head injury decreased from 35% to 27% but polytrauma cases increased from 15% to 37% (Fig. 1). Comparing the injury types a distinct improvement could be found in accidents with small-class cars: pelvic fractures occurred more frequent while in contrast relevant injuries of head, neck, chest and the legs decreased (comparison for all cases see Fig. 2). Pedestrians injured by medium-class and high-class cars in period B sustained less frequently skull fractures, significant intracranial haemorrhages, cervical and femoral fractures than in period A – but an increase of rib and pelvic fractures as well as intraabdominal injuries. At first sight, the injury combination head–chest–lower-limb was the most frequent in killed pedestri-
Causes of death 1978-85
Percent
30%
1991-2004 37%
35%
27% 20%
23%
15%
10%
15% 8%
3%
1%
12%
10%
8%
7%
0% 1
2
3
4
5
6
7
1
Cause of death
2
3
4
5
6
7
Cause of death
1 Head 2 Polytrauma 3 Haemorrhag. shock 4 Head destruction 5 Pneumonia 6 Pulmonary thrombembolism 7 Others Fig. 1. Causes of death.
S326
E. Ehrlich et al. / Legal Medicine 11 (2009) S324–S326
Injury combinations
Body regions
1978-85 6-0-0 5-6-0 5-0-0 4-5-6 3-6-0 3-5-6 3-4-5 3-0-0 1-6-0 1-5-6 1-5-0 1-4-5 1-3-6 1-3-5 1-3-4 1-2-5 1-0-0 0-0-0
1991-2004
8%
12%
19%
34%
33% 13%
0%
10%
20%
30%
0%
10%
Percent
20%
30%
Perzent
Combinations of the 3 most injured regions 1 Head / neck 2 Face 5 Pelvis/lower leg
3 Chest 4 Abdomen 6 Body surface
Fig. 2. Combinations of most severely injured regions.
impacts as well as higher impact speeds of the upon laded upper part of the body [1]. The frequency of lower leg fractures in both periods was similar. Lower positioned bumpers obviously spare the knee region and reduce not the frequency, but the severity of lower leg fractures if they are (non-prominently) integrated in the front of the car [7]. 5. Conclusion A comparison of the injury patterns in pedestrians killed in traffic accidents by impacts of passenger cars, build in two different periods (‘‘older” and ‘‘new”) – with alterations of their frontal form – yielded a shifting of the predominant injury focus from the upper (head) to the medium (chest, abdomen, pelvis) body region and a reduction of the frequency of femoral fractures. Conflict of interest None.
References [1] Friesen F, Wallentowitz H, Philipps M. Optimierte Fahrzeugfront hinsichtlich des Fußgängerschutzes. Berichte der Bundesanstalt für Straßenwesen: Fahrzeugtechnik. Heft 2001;F38:44 S. [2] Glaeser K-P. Der Anprall des Kopfes auf die Fronthaube von Pkw beim Fußgängerunfall. Berichte der Bundesanstalt für Straßenwesen: Fahrzeugtechnik. Heft 1996;F14:100 S. [3] Mattern R. Veränderte Verletzungsmuster durch neue Kfz-Sicherheitsstandards anhand aktueller Unfallabläufe. Vortrag anlässlich der 60. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie 1996:4 S. [4] Schindler V, Kühn M, Weber S, Siegler H, Heinrich T. Verletzungsmechanismen und Wirkabschätzungen der Fahrzegfrontgestaltung bei Pkw-FußgängerKollisionen. Abschlußbericht im Auftrag der Deutschen Versicherungswirtschaft e.V. TU-Berlin Fachgebiet Kraftfahrzeuge (GDV) 2004:36–40. [5] Bockholdt B. Tödliche Fußgänger-Pkw-Kollisionen in beiden Teilen Berlins 1980–1990. Med Diss 1995:50S. [6] Ettemeyer M. Untersuchung tödlicher Fußgänger-Pkw-Unfälle hinsichtlich der Auswirkungen der Fahrzeugfront auf das Verletzungsmuster der betroffenen Fußgänger. Med Diss 1991:46 S. [7] Otte D, Pohlemann T. Analyse und Bewertung des Sekundäraufpralles auf die Straße bei Pkw-Fußgänger-Kollisionsabläufen. Verkehrsunfall und Fahrzeugtechnik 2002;10:261–7.