Teenage Activities and Postures when Passengers in a Vehicle Environment

An observational investigation was first conducted to identify the common activities of teenage occupants in a vehicle environment. These included playing or texting on a cell phone, grabbing objects in a schoolbag positioned in the footwell, applying make-up while looking in the visor mirror (female), texting with legs crossed (male), looking down at an object, reaching for objects, and changing the radio. These activities were simulated in a static user study. The back of the head-to-head restraint anterior surface was 2.1 ± 2.7 cm for male volunteers and 3.5 ± 2.2 cm for female volunteers while normally seated. In comparison to when normally seated, the head moved 8.0 ± 3.8 cm and 4.3 ± 2.8 cm respectively when the volunteers were interacting with a cell phone. The back of the head-to-head restraint anterior surface was 59.4 ± 5.9 cm for the male volunteers and 55.8 ± 5.1 cm for the female volunteers when grabbing a book in the footwell area. The results were, however, similar (65.7% ±.8.0% v 65.9% ±.6.4%) when normalized by seated height. The head rotated 27.2 ± 14.7 deg in males and 19.1 ± 8.9 deg by females when playing a game on the cell phone. The results of this study highlight the increase in head-to-head restraint and head rotation during common activities conducted by teenagers when riding in the front-seat.