Effects of shaking and centrifugation on human sperm motility.

Fresh seminal specimens from 48 normospermic donors were subjected to shaking and centrifugation at various intensities and durations, and their effect on sperm motility was determined objectively by the multiple exposure photography (MEP) method. Shaking for 15 sec by mechanical vibrator did not induce any drop in serum percentage of motility, while shaking for 30 to 180 sec was followed by immediate drop of this parameter. Sperm velocity increased for a short duration in all shaken specimens, after which it dropped considerably in most cases. Following centrifugation below 330 g for 10-20 min, sperm motility was almost unaffected. However, there was a significant drop in sperm motility after specimens were subjected to rates above 580 g for the same time duration. Intensive shaking and centrifugation significantly increased the percentage of dead spermatozoa, as confirmed from the combined supravital staining and MEP technique.