ABSTRACT
CIREN and NASS-CDS databases were used to analyze nearside impact injuries. Front seat occupants with and without shoulder injuries were examined on an individual basis in both databases. All vehicles were from model year 2000 or newer. Variables such as the type of collision, change in velocity, principal direction force, demographics, injuries scored by the MAIS and ISS metrics, and injuries to the head, thorax, abdomen and pelvis were included. Shoulder injuries included fractures to the humerus, scapula and clavicle, and associated joint traumas. The median changes in velocities for occupants with and without shoulder injuries were 36 and 32 km/h in CIREN and 29 and 32 km/h in NASS databases. Approximately two-thirds of all cases occurred below 40 km/h. In both databases, the clavicle, scapula and humerus fractures, and AC joint dislocations were found, and the scapula fracture was associated with the clavicle, AC joint, acromion and humerus injuries in few occupants. The clavicle fracture was associated with AC joint and humerus injuries only in the NASS database. Thorax, abdomen and pelvic injuries and skull fractures increased with the presence of shoulder injuries in both databases, albeit not at the same rate. Anterior oblique loading was more frequent than pure lateral loading in both databases suggesting the importance of the oblique vector in side impact trauma. These findings underscore a need for detailed examinations of shoulder load-sharing using biomechanical studies to better understand its role in side impact traumas, shoulder biofidelity and injury assessments in dummies.
ABSTRACT
This study analyzed skeletal and organ injuries in pure lateral and oblique impacts from 20 intact post mortem human surrogate (PMHS) sled tests at 6.7 m/s. Injuries to the shoulder, thorax, abdomen, pelvis and spine were scored using AIS 1990-1998 update and 2005. The Injury Severity Scores (ISS) were extracted for both loadings from both versions. Mean age, stature, total body mass and body mass index for pure lateral and oblique tests: 58 and 55 years, 1.7 and 1.8 m, 69 and 66 kg, and 24 and 21 kg/m(2). Skeletal injuries (ribs, sternum) occurred in both impacts. However, oblique impacts resulted in more injuries. Pure lateral and oblique impacts ISS: 0 to 16 and 0 to 24, representing a greater potential for injury-related consequences in real-world situations in oblique impacts. Internal organs were more involved in oblique impacts. ISS decreased in AIS 2005, reflecting changes to scoring and drawing attention to potential effects for pre-hospital care/medical aspects. Mean AIS scores for the two load vectors and two AIS coding schemes are included. From automotive crashworthiness perspectives, decreases in injury severities might alter injury risk functions with a shift to lower metrics for the same risk level than current risk estimations. This finding influences dummy-based injury criteria and occupant safety as risk functions are used for countermeasure effectiveness and cost-benefit analyses by regulatory bodies. Increase in organ injuries in oblique loading indicate the importance of this vector as current dummies and injury criteria used in regulations are based on pure lateral impact data.
