The HIC had the strongest correlation to the payload mass moment of inertia about the axis formed between the initial contact point on the CRS and outboard lower anchor. Therefore, the most favorable geometry of a CRS for near-side impact would be to design and position the initial impact point close to the combined CRS and ATD CG. By reducing the axis of rotation or mass of the CRS, the payload would have a lower moment of inertia, and the risk of injury to the head could be reduced, all else equal.
Price et al. (Mon,) studied this question.