It had the shortest duration and fewest contractions. Each man's pattern of contractions was very similar from one session to the next and distinguished his records from others'. Area under the pressure curve, reflecting muscular exertion during contraction, generally increased throughout the regular series.
Pulsating Orgasm | PC Muscle Contractions During Ejaculation - herbertkikoy.info
Eleven young adult male subjects were each recorded for three sessions of masturbation to orgasm.