Minor Vehicle Collision and Injury Analysis André M. Loyd, Ph.D. Biomechanical Engineer
Personal Bio Education Post-Doctoral Fellowship at the Mayo Clinic - Helmets and Neck Guards in Hockey Ph.D. and Master in Biomedical Engineering - Dissertation: Pediatric, Adult and ATD Head Impact Properties - Specializing on Pediatric Injury B.S. in Mechanical Engineering at Clemson University Experience - Minor: Bioengineering - Senior Thesis: Knee joints S-E-A, Ltd. - Biomechanics Specialist Injury Reconstructionist - Accident Reconstructionist
Minor Impacts Defined Delta-V (Change in velocity) <5mph 5-10mph Types of impacts Bumper to bumper Override/underride Sideswipes Bumper-to-Bumper Sideswipe Override/underride
Minor Impacts Defined Delta-V <5 mph 5-10mph Types of impacts Bumper to bumper Override/underride Sideswipes Bumper-to-Bumper (www.iihs.org) Corner Bumper (www.iihs.org)
Minor Impacts Defined Delta-V <5mph 5-10mph Types of impacts Bumper to bumper Override/underride Sideswipes
Minor Impacts Defined Delta-V <5mph 5-10mph Types of impacts Bumper to bumper Override/underride Sideswipes
Minor Impacts Injuries Injury claims Head (concussions) Neck (whiplash) Back Shoulder Typically not visible damage MRI CT scans Persistent pain
Minor Impact Analysis Accident Reconstruction Goals Delta-V o Change in velocity of vehicle o Delta-V = V 1 -V 2 Injury Analysis Goals Calculate acceleration of the body Quantify injury risk Pre impact Post impact V 1 V 2
Materials Needed Photographs of vehicles Inspection of vehicle if available Police reports Accident location documentation Site inspection if case goes to trial Repair estimates Used for accident reconstruction Medical records for injury claims Height and weight of passengers Used for calculations Deposition of injured party Description on how the body moved
Review documents Police reports Witness statements Photographs Inspections as needed Site inspection Vehicle inspection Classification of accident Bumper-to-bumper Sideswipe Override/underride Accident Reconstruction
Find similar crash tests Insurance Institute for Highway Safety Analysis technique based on damage type Bumper-to-bumper o Cipriani et al. 2002 Override/underride o Fugger et al. 2003 Sideswipe o Toor et al. 1999 Momentum analysis Energy Analysis Goal: Delta-V Accident Reconstruction V 1 V 2
Injury Analysis Kinematics Rear impacts Body moves backwards relative to the vehicle Front impacts Body moves forward relative to vehicle Advance Simtech
Head Accelerations (g) Injury Analysis Delta-V of car to accelerations on body Injury risk of acceleration Injury risk curve Compare acceleration to everyday activities Running, jumping, and heading a ball 7 6 5 4 Rowson et al. 2011 3 2 1 0 Hopping Bumper Car Falling into a chair Welcher et al. 2001 Delta-V 3.5mph
Frontal impact Lady backed into by a Napa truck Damage to the right front bumper Injuries Concussion, Elbow Neck pain Claims head impacted passenger window and armrest Case #1: Frontal Impact
Case #2: Rear Impact Honda Civic rear impacts a Bravada Head Injury Bravada driver claims head hit A-pillar Override/underride $3000 damage to Civic Delta-V at 3mph for Bravada
Case #2: Rear Impact Kinematics Assumed driver hit window frame Head accelerations 5g Heading soccer ball= 12g (Hanlon and Bir 2010)
Case #3: Elderly Minivan backed into Driver 70 year-old female 110 pounds and 5 4 Claims Neck injury
Neck Shear Force (#) Case #3: Elderly Minivan backed into Driver 70 year-old female 110 pounds and 5 4 Claims Neck injury 200 150 100 50 0 Incident Injury threshold
Force (#) Hyundai is rear ended Damages rear trunk 40 year-old male 195 lbs and 6 0 Claims shoulder injury Case #4: 10mph Delta-V Delta V= 10mph Force on each shoulder o 160 lbs 180 160 140 120 100 80 60 40 20 0 Office glass door Avg. pulling strength Pull up Incident
Questions? André M. Loyd, Ph.D. Email: AndreL@CraneEngineering.com Phone: (763)557-9090