Vehicle occupant kinematics in the pre‐crash phase is strongly influenced by active muscle contribution. In order to determine the human response to low‐load situations prevalent in the pre‐crash phase 21 healthy male volunteers (co‐driver, age: 33.4±8.8 y, mass: 78.5±6.3 kg, height: 179.2±4.6 cm, sitting height: 91.0±2.0 cm) were subjected to a series of lane change maneuvers with peak accelerations of around 1 g in lateral direction. Three awareness conditions were realized: an unaware, an anticipated and an informed condition.
Surface Electromyograms (EMG) were recorded bilaterally on three neck muscles (m. sternocleidomastoideus, m. trapezius p. cervicalis and p. descendens) and four trunk muscles (m. rectus abdominis, m. obliquus externus abdominis, m. latissimus dorsi, erector spinae (lumbar region)) and are supplemented with occupant and vehicle kinematics data.
In the subsequent EMG analysis mean onset latencies between 0.106±0.020 s and 0.171±0.047 s were found, where neck extensors responded with the shortest latency. For selected conditions and muscles significantly shorter onset latency was recorded on the right side.
Significantly higher activations of the right muscles were observed in the first part of the maneuver, while only a limited number of muscles showed an effect of the awareness condition.