Crash Injury Mechanisms & Restraint Technologies Road Safety Roadway and Infrastructure Driver Behavior Vehicle Design Crashworthiness Presenter: Rob Kaufman B.S. Mathematical Sciences Sr. Research Scientist Engineer U of WA Crash Kinematics Reconstructionist Crash Injury Research and Engineering Network www.nhtsa.gov/ciren or find link at HIPRC.org Real world laboratory of motor vehicle crashes created by NHTSA in 996. Harborview Injury Prevention and Research Center is one of 6 trauma centers contributing to the CIREN network for NHTSA. CIREN Crash Injury Research and Engineering g Network www.hiprc.org nhtsa.dot.gov CIREN on the Web Quarterly Presentations Electronic Cases (Queries) Injury Mechanism Themes Annual Reports CIREN Goals Provide data on injuries occurring in real world crashes Provide feedback on vehicle safety design for: Auto manufacturers FMVSS Provide outreach and training Determine and document specific injury mechanisms and forces in real world crashes.
Trauma Surgery CIREN SEATTLE Epidemiology Crash Biomechanics & Engineers CIREN Network Detailed Crash/Medical Data Crash Biomechanics NHTSA- Safety standard Auto Manufacturers - Safer Vehicles Training of Trauma Care Providers -Better Triage- Transport REDUCE ECONOMICS COST SAVE LIVES SEATTLE CIREN Epidemiology HIPRC Level Trauma Center RESEARCH FINDINGS Outreach Public - seatbelt use Law enforcement Traffic Safety interests MVC ~ $450 billion/year Critical Clues at Crash Given a Damaged Vehicle Given an Injury» Injury Direction of Force or type of crash Critical Clues at Crash One can determine an injury mechanism based on the following: Restraint status ( most important ) witness, first responder, locked open, belt burns Seat Location Occupant compartment intrusion Intrusion = Injury!! How much Force, based on vehicle damage Direction of Force ( most difficult ) FRONTAL Longitudinal intrusion = Frontal PDOF A Pillar movement Side Impact Mechanism Reviews Intrusion = Injury Thorax Abdominal LateralPelvis Bilateral Pelvis Combination No intrusion i Intrusion increases forces on Ride down space occupant and severity of injury SIDE Lateral intrusion = Lateral PDOF
P N Results NASS MAIS v Door intrusion njury AIS Maximum in 6 5 4 3 0 NASS Max AIS vs door intrusion y = 0.05x +.6 R = 0.9 0 0 40 60 80 Door intrusion (cm) Moderate and serious pelvic injury in nearside crashes by magnitude of intrusion 6 4 0 8 6 4 0 3<8 cm 8<5 cm 5<30 cm 30<46 cm 46<6 cm >=6 cm Consoles No console Tencer A., Kaufman R., Mack C., Mock C. Factors affecting pelvic & thoracic forces in near-side impact crashes: a study of US-NCAP, NASS, and CIREN data. Accident Analysis and Prevention, In Press cement art structure Side Airbag Head Protection Subject Vehicle Damage Rolled rearward and light impact to back bumper P light pole cm =.5 M P P P P Subject V- Four Door sedan Subject - Front Right Passenger V - 000 Ford Expedition Right side direct lateral impact Delta V Oldmiss = 8 mph PDOF = 70 Extrication to door Profile adjusted Demographics/Contacts 3 yr. Female 6, 60 lbs. No Manual belts used Side door airbag deployment Intrusions Lower door panel to lower chest/abdomen Pelvis scuff pillar to B Seatbelt locked in position by intrusion 3
Door Mounted Side Airbag Main protection to upper thorax, but extends enough upward for some head protection Injury Summary Head - Slight LOC on scene -Probable deceleration of head into side airbag. Chest - R Rib fx 7- - Probable lower door panel intrusion Pelvis - Right inferior pubic root, inferior rami and Zone I and II sacral fractures - Probable B pillar intrusion Upper chest and head appear to be protected by door mounted side impact airbag considering an SUV upper door impact. Larger Vehicle and Side Impacts Increasing LTV-Car Fatalities Fatalities in Vehicle-to-Vehicle Collisions 7,000 6,000 5,000 Fatalitie es 4,000 3,000 Incompatibility crashes Some bumper heights are overriding the side impact supports Car-Car Collisions,000 LTV-Car Collisions LTV-LTV Collisions,000 0 980 98 984 986 988 990 99 994 996 998 Intrusion = Injury Abdominal Injuries Observed Upper door panel intrusion Think Thorax!! Think Head, if external marks - Side impacts appear to increase the risk of abdominal injuries - The stiffness and geometry of the door panels along with the protruding components, such as the armrest appear to become forced into the abdomen of the occupant. Armrest 4
Occupant Contacts Upper Door Panel Scuff Head Injuries Nirula R, Mock CN, Kaufman R, Rivara FP, Grossman D. Correlation of head injury to vehicle contact points using Crash Injury Research and Engineering Network (CIREN) data. Accident Analysis and Prevention, 35: 0-0, 003. Protruding Armrest scuffed B pillar / Door panel cracked Direct contact sources for critical head injuries occur to roof structure, rails and pillars B D E C A F A C D E B Side Airbags Provide Head Protection A- A pillar D- Window sill B- B pillar E- Door panel C- Roof side rail F- Windshield Header Frontal Crash Injury Mechanisms Relative risk of death compare to no restraints Lap/shoulder 0. ( 86% reduction) Shoulder only 0.7 ( 34% reduction) 0 0. 0. 0.3 0.4 0.5 0.6 0.7 0.8 0.9 LS All Frontal Auto Shoulder Rivara FP, Koepsell TD, Grossman DC, Mock C: Effectiveness of automatic shoulder belt systems in motor vehicle crashes. JAMA, 93; 86-88,000. 5
Seattle CIREN Research Publication (FARS data) Rivara F, Cummings P. Car occupant death according to the restraint use of other occupants: a matched cohort study. JAMA. Jan ;9(3):343-9, 004 Occupant energy distribution - Restrained occupants can have an increased risk of death by -5% with an unrestrained person in the vehicle behind or next to them. - out of 6 deaths may have been prevented if the other occupants were restrained - To reduce the risk of death, all occupants must be restrained in the vehicle Restrained vs. Unrestrained/Intrusion 00lbs 00lbs 00lbs 00lbs 00lbs 00lbs 00lbs 00lbs 00lbs 00lbs Padded Knee Bolsters 500lbs 500lbs 500lbs 500lbs 500lbs 500lbs Seat belt distribution of force on body Buckle Pretensioner Safety Belt Retractor Pretensioner IGNITION DEPLOYMENT 6
Direct Contact Forces to Lower Extremities Axial load and force to lower extremity Patella - knee cap FRONTAL FORCE - Body acceleration is less likely to cause fracture at the upper leg unless it has struck a very stiff area - Occupant movement into stiff toe pan can result in fractures in the ankle region FORCE Tibia Plateau Fx FORCE Foot/Ankle Splitting Condyles (Distal Femur) Femoral neck - bending Dislocation or fracture of acetabulum Femur mid-shaft bowing or bending or oblique fractures External and Internal Force Calculation Estimate ed femur load (N) 30000 5000 0000 5000 0000 INTERNAL FORCE EXTERNAL FORCE Offset Frontal Impacts with Vehicle Mismatch 5000 0 3 4 5 6 7 8 9 0 3 4 5 6 7 8 9 0 Tencer A, Kaufman R, Ryan K, Grossman D, Henley MB, Mann F, Mock C, Rivara F, Femur fractures relatively low speed frontal crashes: The possiblerole of muscle forces. Accident Analysis and Prevention, 34(00) -. Front Passenger Vehicle into Front LTV SUV-Truck vs. Sedan Override impact creates significant intrusion of instrument panel/hood AIS > SUV bumper into grill of sedan Sedan bumper into front tire/axle 7
Injuries to LTV s front seat occupants in head-on collisions with PV s No belt use, chest displacement/force greatly increases AIS > MAthematical DYnamic Modeling- MADYMO No seatbelt - increases force on LE The Effects of Seatback Reclined Positions of Occupants in Motor Vehicles Collisions Seattle CIREN Team (Bulger, Dissanaike, Kaufman, Mack) University of Washington Harborview Injury Prevention and Research Center MAthematical DYnamic Modeling- MADYMO Dissanaike S, Kaufman R, Mack CD, Mock C, Bulger E. The effect of reclined seats on mortality in motor vehicle collisions. The Journal of Trauma, Injury, Infection and Critical Care. 008 Mar;64(3):64-9. Seatback Recline CIREN Case Review Scene Seatback Recline CIREN Case Review Vehicle N SHOULDER NOT TO SCALE Head-on GRASSY MEDIAN Full frontal crash POLICE MEASURED 80 FEET/5M OF TIRE LOCKUPS SHOULDER Speed Limit 70mph/kmph 003 Compact 4 door sedan PDOF o clock Delta V = 44kmph/ 7 mph (smash missing run) 8
Seatback Recline Case Review Case Occupant Seatback Recline CIREN Case Review Injuries 0 s yr. Female Lap/shoulder & Air bag Fully reclined seatback position and sleeping AIS 3 T-Spine AIS 3 Lower Extremity Seatback Recline Case Review Occupant Kinematics Seatback Recline Case Review Occupant Kinematics Demographics Upright (7.6%) PR (50%) FR (0.3%) Age (yrs) 39.4 35.7 9.6 Male gender (%) 7775 (48.8%) 4705 (54.7%) 97 (70.4%) Height (cm) 70. 7.4 74 Weight (kg) 75.9 75.8 79 Mortality risk regression analysis Difference in mortality persist when adjusted for age, sex, seatbelt use and type of vehicle Mortality Risk Odds Ratio 95% CI Partial Reclined.4.0. Fully Reclined.77.3.78 9
Conclusion: Fully reclined occupants are predominantly young, male and not wearing a seatbelt Clothesline type Chest and spinal injuries with the shoulder belt appear to be one mechanism in fully reclined occupants wearing a seatbelt. Fully reclined seats are an independent risk factor for death in motor vehicle collisions Slightly reclined seats have a small increase in mortality An Evaluation of Spinal Cord Injury (SCI) Associated with Motor Vehicle Crashes including Rollovers Eileen Bulger, MD Robert Kaufman, BS Chris Mack, MS Stephen Burns, MD University of Washington Rollovers and Body Type Rollover Type Car/Van/Other (%) SUV/Pickup (%) None 95.03 8.60 /4 turn 0.77 4.06 / turn or greater 4.0 4.34 LTV body types were 3.7 times more likely to experience any degree of a rollover (/4 turn or greater) Rollover Types with ASI-SCI Rollover Type Vehicle Body Type ASI (%) SCI (%) None 0.49 0.0494 /4 turn.308 0.6 / turn or greater.773 0.69 Car/Van/Other /Oth 0.67 0.064064 SUV/Pickup 0.86 0.086 Source: NASS-CDS Source: NASS-CDS includes those in multiple crash events ASI Any Spinal Injury or fracture SCI Spinal Cord Injury Roof Crush and ASI-SCI 8 Percent SCI by Roof Crush Among Belted Occupants 7 Percentage of Occupan nts with ASI or SCI 6 5 4 3 0 None 3-8 cm 8-5 cm 5-30 cm 30-45 cm 45-60 cm >60 cm Roof Crush ASI SCI Source: NASS-CDS 993-006 3 < 8cm 8 < 5cm 5 < 30cm 30+ cm Roof Crush 0
Review Side Impacts Intrusion = Injury MthLt Match Lateral/Vertical ti l intrusion to body region Head contacts to Roof Pillars Intrusion = Injury Thoracic Injuries Pli Pelvic Fxs Roof crush Intrusion = Injury UPPER LEGS End View Intrusion = Injury PELVIS Armrest Abdominal Injuries
Review Frontal limpacts Front crush depth/a Pillar movement INTRUSION = INJURY!! Steering column deformation No Seatbelts, increased severity Demographics Obesity, Elderly Driver Braking lockups Right leg, foot/ankle fxs Axial load and force to lower extremity FORCE FORCE Patella - knee cap Splitting Condyles (Distal Femur) Femoral neck - bending Dislocation or fracture of acetabulum Foot/Ankle Femur mid-shaft bowing or bending or oblique fractures
CIREN Seattle Research Publications Tencer A, Kaufman R, Ryan RanK, Grossman D, Henley MB, Mann F, Mock C, Rivara F, Wang S, Augenstein J, Hoyt D, Eastman B. Femur fractures in relatively low speed frontal crashes: The possible role of muscle forces. Accident Analysis and Prevention, 34(00). Nirula R, Mock CN, Kaufman R, Rivara FP, Grossman D. Correlation of head injury to vehicle contact points using Crash Injury Research and Engineering Network (CIREN) data. Accident Analysis and Prevention, 35: 0 0, 003. Nirula R, Kaufman R, Tencer A. Traumatic brain injury and automotive design: making motor vehicles safer. Journal of Trauma, 55:844 8, 003. Acierno S, Kaufman R, Mock C, Rivara F, Grossman D. Vehicle mismatch: Injury patterns and severity. Accident Analysis and Prevention 39 (004) 76 77. 77 Tencer A., Kaufman R., Mack C., Mock C. Factors affecting pelvic and thoracic forces in near side impact crashes: a study of US NCAP, NASS, and CIREN data. Accident Analysis and Prevention 37 (005) 87 93. 93 Tencer A., Kaufman R., Huber P., Mock C. The Role of Door Orientation on Occupant Injury in a Nearside Impact: A CIREN, MADYMO modeling and Experimental Study. Traffic Injury Prevention, 6:37 378, 378 005
CIREN Seattle Research Publications Dissanaike S, Kaufman R, Mack CD, Mock C, Bulger E. The effect of reclined seats on mortality in motor vehicle collisions. The Journal of Trauma, Injury, Infection and Critical Care. 008 Mar;64(3):64 9. Burns S, Mack C, Kaufman R, Bulger E. Cost Of Spinal Cord Injuries Caused By Rollover Automobile Crashes. Injury Prevention00;6:74 78. Mandell S, Kaufman R, Mack C, Bulger E. Mortality and Injury Patterns Associated with Roof Crush in Rollover Crashes Accident Analysis and Prevention In press/on line (00), doi:0.06/j.aap.00.0.03 Kuan JK, Kaufman R, Wright JL, Mock C, Nathens AB, Wessells H, Bulger E. Renal injury mechanisms in motor vehicle collisions: analysis of the Crash Injury Research and Engineering Network (CIREN) dataset. Journal of Urology Vol. 78, 935 940, September 007 Linnau K., Blackmore C., Kaufman R., Nguyen, T., Routt M., Stambaugh L., Jurkovich G., Mock C. Radiographic patterns of pelvic ring disruptions: Do initial radiographs tell the truth about the crash? Journal of Orthopaedic Trauma. (6):375 380, July 007.
Rob Kaufman Handouts on-line and CIREN web links Dissanaike S, Kaufman R, Mack CD, Mock C, Bulger E. The effect of reclined seats on mortality in motor vehicle collisions. The Journal of Trauma, Injury, Infection and Critical Care. 008 Mar;64(3):64-9. http://www.nhtsa.gov/dot/nhtsa/nvs/ciren/007%0presentations/seattle0307.pdf Burst Fracture of the L-spine in Frontal Crashes http://www.nhtsa.gov/dot/nhtsa/nvs/ciren/009%0presentations/seattleoct09.pdf Burns S, Mack C, Kaufman R, Bulger E. Cost Of Spinal Cord Injuries Caused By Rollover Automobile Crashes. Injury Prevention 00;6:74-78. Mandell S, Kaufman R, Mack C, Bulger E. Mortality and Injury Patterns Associated with Roof Crush in Rollover Crashes Accident Analysis and Prevention In press/on line (00), doi:0.06/j.aap.00.0.03 http://www.nhtsa.gov/dot/nhtsa/nvs/ciren/008%0presentations/seattleciren.pdf Tencer A., Kaufman R., Mack C., Mock C. Factors affecting pelvic and thoracic forces in near-side impact crashes: a study of US-NCAP, NASS, and CIREN data. Accident Analysis and Prevention - 37 (005) 87-93. Tencer A., Kaufman R., Huber P., Mock C. The Role of Door Orientation on Occupant Injury in a Nearside Impact: A CIREN, MADYMO modeling and Experimental Study. Traffic Injury Prevention, 6:37-378, 005 http://www.nhtsa.gov/dot/nhtsa/nvs/ciren/006%0presentations/seattleciren pubmeetingsideimpactforweb3-30-06.pdf CIREN -Crash Injury Research and Engineering Network Link All CIREN Technical Publications and CIREN case data study access http://www.nhtsa.gov/ciren