**6. Conclusions**

Among different seating orientations of 360 degrees respect to the impact direction under the 40 kph frontal crash pulse, the side-facing positions were identified as worst cases in which the occupant had the highest risks of combination of the head and chest injuries indicated with the largest BrIC and lateral chest deflection, while the rear facing seated occupant had the highest risk of cervical spinal neck injury due to the neck hyperextension.

For the US regulatory (NCAP and IIHS) vehicle frontal and oblique crash tests (including NCAP rigid barrier frontal crash, the IIHS 40% offset deformable barrier frontal crash, and the IIHS small overlap rigid barrier frontal crash), as well as the vehicle rear crash test, side protection of a side-facing seated occupant is required. As the crash severities increased to 65kph or 35 mph of delta velocity, the side-facing occupant with the 3 pt. seatbelt alone could suffer high injury risks for the multiple body regions of head, chest, abdomen, pelvis, and the lower extremities.

Under the US regulatory (NCAP and IIHS) vehicle far side crash tests (including the US NCAP moving deformable barrier far side crash and the IIHS moving deformable high barrier far side crash), frontal protection for a side-facing seated occupant restrained with a 3 pt. seatbelt is necessary. Such an occupant could suffer moderate to high injury risks for the head, chest, and the lower extremities.

Under the US regulatory (NCAP and IIHS) vehicle near side crash tests (including the US NCAP moving deformable barrier near side crash and the IIHS moving deformable high barrier near side crash), a side-facing seated occupant will experience the rear impact under large pushing force from the seat due to the side door structure intrusion. With the seat and 3 pt. seatbelt restrains, such an occupant could suffer moderate injury risks for the head, neck and chest.

The new restraint concepts developed for the side-facing seat occupant in Section 5 demonstrated significant improvement for mitigation of the occupant's body injuries for all the vehicle crash test conditions considered in this study.
