Reduction in the number of pedestrian fatalities is one of the most significant issues in Japan. To address this issue, it is critical to estimate pedestrian kinematics, especially head impact locations during car‐to‐pedestrian impacts. In this study, we developed a pedestrian whole body finite element model with muscles which we call Active THUMS and validated the model with no activation against three series of human cadaver test data on quasi‐static 3‐point bending tests, shearing and bending impacts for pedestrian knees using two subjects and a SUV‐to‐pedestrian impact using one subject. The model was used for a preliminary study to investigate muscular effects on pedestrian kinematics and injuries, especially on the head‐neck kinematics and brain injuries during SUV‐to‐pedestrian impacts. We hypothesized three types of activation levels of an assumed tensed condition, measured EMG data and only neck muscles from the literature. The comparison of simulation results with and without muscle activity showed that muscle activity altered pedestrian kinematics in the head and lower extremities and decreased skeletal injury risks and neck elongation. These findings partially correspond to differences in pedestrian injury patterns between cadaver test data and accident cases. Further studies are needed to estimate the muscle activation levels of pedestrians.