The title of this master thesis is "activation timing of the neck and trunk muscles during sudden free fall of the head and torso". The measurements in this thesis should provide a first step in creating a realistic human model for traffic accident simulations. Therefore, measurements were made to determine the muscle reaction time when a subject was exposed to free fall, taking into account human movement. Two test setups were created to simulate the free fall of either the head or the torso in both lateral and prone positions. The lateral tests were all done with the subjects lying on their right hand side. Seven volunteers were used for the head investigations, while six volunteers were used for the torso investigations. All subjects had similar body sizes with an average height of 172 cm (+/- 3 cm) and an average weight of 76 kg (+/- 14 kg). Each of the four test series conducted were further split up depending on whether the subject was prepared or unprepared for the free fall.The muscle activity of seven muscle groups in the neck and trunk area was measured. For this purpose, a wireless transmitter 16 channel amplifier system was used (Myon 320, Myon Schwarzenberg, Switzerland). The data was sent to a Dewetron 2602 computer (Dewetron 2602, Dewetron Grambach, Austria). For the three-dimensional video recording we used a 3D kinematic system (Vicon V612 DataStation, Vicon Oxford, UK). Before the actual tests were started the maximum contraction of all muscle groups in each of the volunteers was measured.The results of the EMG measurements show an average muscle activation latency of 25 ms to 50 ms, differing from muscle to muscle. A difference in latency between prepared and unprepared attempts was also detected. The variation in muscle activation latency during prone tests was rather low. For tests done in the lateral position however, the muscles on the left side showed clearly lower activation latency than the those on the right side.