Table 2.
Kinematic variables (mean ± SD) of the four ejaculate clusters (ECs).
| Variable | EC1 | EC2 | EC3 | EC4 |
|---|---|---|---|---|
| VCL | 92.08 ± 5.12 a | 75.19 ± 4.54 b | 65.48 ± 6.07 c | 68.57 ± 9.98 b,c |
| VSL | 38.09 ± 6.52 a | 42.91 ± 2.76 a | 31.69 ± 3.48 b | 24.00 ± 4.68 c |
| VAP | 51.79 ± 3.28 a | 50.16 ± 3.43 a | 41.30 ± 3.43 b | 37.21 ± 5.56 b |
| LIN | 42.23 ± 6.68 c | 57.17 ± 3.59 a | 49.53 ± 4.49 b | 37.26 ± 5.37 c |
| STR | 71.44 ± 7.51 b,c | 82.34 ± 1.50 a | 75.72 ± 5.58 b | 65.48 ± 6.66 c |
| WOB | 57.49 ± 4.54 b | 67.35 ± 3.61 a | 63.72 ± 2.86 a | 55.45 ± 3.75 b |
| ALH | 3.46 ± 0.23 a | 2.73 ± 0.17 b | 2.47 ± 0.20 b | 2.70 ± 0.35 b |
| BCF | 8.93 ± 0.59 | 8.36 ± 0.43 | 8.73 ± 0.52 | 8.44 ± 0.87 |
EC1: rapid, progressive and undulatory; EC2: medium velocity and linear progressive; EC3: slow, progressive and undulatory; EC4: slow velocity, nonlinear and non-progressive. Number of ejaculates = 40. VCL: curvilinear velocity (µm·s−1); VSL: straight line velocity (µm·s−1); VAP: average path velocity (µm·s−1); LIN: linearity of forward progression (%); STR: straightness (%); WOB: wobble (%); ALH: amplitude of lateral head displacement (µm); BCF: beat-cross frequency (Hz). SD: standard deviation. a–c Different letters indicate differences between ejaculate clusters. p < 0.05.