Injuries in running are often provoked by fatigue or improper technique, which are both reflected in the runner's kinematics. State of the art research on kinematics in sports is using optical motion capture systems that are inaccessible to most athletes. This paper demonstrates the potential of wearable sensors for runners' kinematics analysis. We present a user study including 21 subjects of different running experience that performed an exhausting run on a conventional outside track wearing ETHOS units. For performance level assessment, training assistance, and fatigue monitoring we extracted the foot contact duration, the foot strike type, and the heel lift as kinematic parameters. A questionnaire revealed that subjects perceived the sensors as comfortable to wear and would use them on a regular basis. We concluded that wearable sensors provide a valuable tool for runners, from beginners to experts, for running technique assessment.