Precision tasks in 3D like object manipulation or character animation call for new gestural interfaces that utilize many input degrees of freedom. We present MotionBender, a sensor-based interaction technique for post-editing the motion of e.g. the hands in character animation data. For the visualization of motion we use motion paths, often used for showing e.g. the movement of the hand through space over time, and allow the user to directly "bend" the 3D motion path with his/her hands and twist it into the right shape. In a comparative evaluation with a mouse-based interface we found that subjects using our technique were significantly faster. Moreover, with our technique, subject movement was more coordinated, i.e. movement was done in all three dimensions in parallel, and the participants preferred our technique in a post-experiment questionnaire. We also found a gender effect: male users both like the gesture interaction better and achieve better performance.