The trajectory of a fall is important, but there are other aspects of a fall, such as the launch and landing phases of the fall, which can also be investigated using physical measurements and calculations. These include measurements of the speeds at which a person can run, jump, dive, be pushed or thrown, an estimate of the rotational speed associated with each launch method, measurements or estimates of runup and takeoff distances, calculations of possible trajectories based on different launch angles and wind speeds, location of the center of mass of a person on video data, and an analysis of possible bounce and impact events. When all the data are combined with other evidence obtained by the police and medical specialists, the circumstances surrounding a fall can sometimes be determined accurately. Often, there is insufficient evidence to arrive at a definite conclusion.