A field-crash-validated female lower extremity injury criterion
Brumbelow, Matthew L.
Proceedings of the 2025 International Research Council on Biomechanics of Injury Conference
September 2025
Abstract
Females are at elevated risk of lower extremity injury in frontal crashes. This study builds on previous research to develop a new female lower extremity injury criterion (FLEIC) calculated from maximum values recorded with the Hybrid III 50th percentile male dummy. For vehicles with good overall driver and structure ratings in the IIHS moderate overlap test, a 5-unit increase in FLEIC (approximately 1 standard deviation) was associated with increases of 50%–60% in the odds of any female driver AIS >= 2 lower extremity injury (p = 0.01) or of an AIS >= 2 right foot/ankle injury (p = 0.01). FLEIC was a better predictor of female injury than toe pan or brake pedal intrusion measured in the crash test. FLEIC was not associated with a significant change in male driver injury risk. Analysis of data and footwell video from 100 recent crash tests showed that FLEIC increased with intrusion magnitude, but the highest values often were observed early in the intrusion phase rather than at maximum intrusion. Loading from a deploying knee airbag was another common contributor to FLEIC. FLEIC exhibits better repeatability than its component measures. Including FLEIC in existing rating programs would help encourage vehicle designs with reduced lower extremity injury risk for female drivers.
Females are at elevated risk of lower extremity injury in frontal crashes. This study builds on previous research to develop a new female lower extremity injury criterion (FLEIC) calculated from maximum values recorded with the Hybrid III 50th percentile male dummy. For vehicles with good overall driver and structure ratings in the IIHS moderate overlap test, a 5-unit increase in FLEIC (approximately 1 standard deviation) was associated with increases of 50%–60% in the odds of any female driver AIS >= 2 lower extremity injury (p = 0.01) or of an AIS >= 2 right foot/ankle injury (p = 0.01). FLEIC was a better predictor of female injury than toe pan or brake pedal intrusion measured in the crash test. FLEIC was not associated with a significant change in male driver injury risk. Analysis of data and footwell video from 100 recent crash tests showed that FLEIC increased with intrusion magnitude, but the highest values often were observed early in the intrusion phase rather than at maximum intrusion. Loading from a deploying knee airbag was another common contributor to FLEIC. FLEIC exhibits better repeatability than its component measures. Including FLEIC in existing rating programs would help encourage vehicle designs with reduced lower extremity injury risk for female drivers.
Abstract
Females are at elevated risk of lower extremity injury in frontal crashes. This study builds on previous research to develop a new female lower extremity injury criterion (FLEIC) calculated from maximum values recorded with the Hybrid III 50th percentile male dummy. For vehicles with good overall driver and structure ratings in the IIHS moderate overlap test, a 5-unit increase in FLEIC (approximately 1 standard deviation) was associated with increases of 50%–60% in the odds of any female driver AIS >= 2 lower extremity injury (p = 0.01) or of an AIS >= 2 right foot/ankle injury (p = 0.01). FLEIC was a better predictor of female injury than toe pan or brake pedal intrusion measured in the crash test. FLEIC was not associated with a significant change in male driver injury risk. Analysis of data and footwell video from 100 recent crash tests showed that FLEIC increased with intrusion magnitude, but the highest values often were observed early in the intrusion phase rather than at maximum intrusion. Loading from a deploying knee airbag was another common contributor to FLEIC. FLEIC exhibits better repeatability than its component measures. Including FLEIC in existing rating programs would help encourage vehicle designs with reduced lower extremity injury risk for female drivers.Males and females, ID: 2339