Figure 2.

Examples of human sperm motility patterns identified during in vitro capacitation. Representative CASA tracks displaying vigorous motility patterns (A–E) after 3 h in capacitating medium were visually classified as progressive (A), intermediate (B), or hyperactivated (C–E).Vigorous motility tracks were enlarged by selecting the track under the software's EDIT function to highlight the difference between the angles of adjacent points. Tracks displaying nonvigorous motility were classified as either slow or weakly motile (F and G, arrows). The images of these nonvigorous motility patterns include nearby vigorous tracks to illustrate the differences in track length.