Table 6. Reliability outcomes from the different RFD calculations for the plantar flexors, for both intra- and intertester repeatability.
The left side of the table gives the results when the absolute maximum was used, and the right side of the table are the results when an average of three trials was used. F-values are printed in bold in case of a systematic error.
| Absolute maximal value | Averaged value | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Intra- tester | F-ratio |
ICC2,1 | CI 95% lower |
upper | Tester 1 average |
Tester 2 average |
% SEM | % MDD | F-ratio | ICC2,1 | CI 95% lower |
upper | Tester 1 average |
Tester 2 average |
% SEM | % MDD |
| RFD (N/s) | ||||||||||||||||
| RFD100 | 0.695 | 0.560 | -0.052 | 0.869 | 746.625 | 632.15 | 44.543 | 123.467 | 0.292 | 0.636 | 0.043 | 0.896 | 406.529 | 448.258 | 40.423 | 31.822 |
| RFD200 | 0.023 | 0.675 | 0.092 | 0.909 | 686.330 | 671.693 | 31.624 | 87.658 | 2.216 | 0.680 | 0.178 | 0.907 | 429.807 | 530.260 | 31.433 | 26.901 |
| RFD300 | 0.109 | 0.692 | 0.133 | 0.914 | 583.479 | 608.662 | 28.624 | 79.343 | 3.165 | 0.650 | 0.125 | 0.898 | 386.341 | 490.906 | 29.965 | 45.475 |
| RFD400 | 0.373 | 0.750 | 0.274 | 0.931 | 491.944 | 524.129 | 23.193 | 64.288 | 4.181 | 0.664 | 0.126 | 0.903 | 336.325 | 428.185 | 26.279 | 52.715 |
| RFD500 | 0.458 | 0.752 | 0.283 | 0.932 | 411.351 | 438.618 | 21.210 | 58.792 | 5.530 | 0.667 | 0.097 | 0.906 | 285.706 | 366.218 | 23.487 | 33.453 |
| RFD600 | 0.416 | 0.722 | 0.217 | 0.923 | 355.576 | 378.774 | 21.891 | 60.679 | 6.696 | 0.659 | 0.059 | 0.905 | 245.003 | 316.536 | 22.015 | 24.153 |
| RFD700 | 0.416 | 0.698 | 0.167 | 0.915 | 308.178 | 328.982 | 22.631 | 62.729 | 6.959 | 0.627 | 0.022 | 0.894 | 212.017 | 277.660 | 22.727 | 44.817 |
| Intertester | ||||||||||||||||
| RFD (N/s) | ||||||||||||||||
| RFD100 | 1.044 | 0.713 | 0.225 | 0.919 | 592.188 | 693.783 | 34.575 | 95.837 | 1.154 | 0.798 | 0.406 | 0.945 | 448.696 | 514.045 | 28.260 | 78.332 |
| RFD200 | 0.928 | 0.728 | 0.251 | 0.924 | 717.820 | 808.531 | 27.582 | 76.453 | 1.331 | 0.762 | 0.330 | 0.934 | 563.401 | 645.111 | 26.210 | 72.651 |
| RFD300 | 3.807 | 0.828 | 0.428 | 0.955 | 685.588 | 796.719 | 17.183 | 47.629 | 6.906 | 0.825 | 0.295 | 0.957 | 543.649 | 660.037 | 16.456 | 45.613 |
| RFD400 | 12.824 | 0.836 | 0.116 | 0.964 | 599.439 | 730.474 | 12.305 | 34.108 | 11.001 | 0.830 | 0.156 | 0.962 | 490.980 | 601.091 | 13.595 | 37.684 |
| RFD500 | 16.701 | 0.806 | 0.006 | 0.959 | 514.88 | 643.033 | 12.112 | 33.572 | 6.886 | 0.811 | 0.268 | 0.953 | 433.878 | 523.619 | 15.974 | 44.276 |
| RFD600 | 14.559 | 0.796 | 0.026 | 0.955 | 451.568 | 564.449 | 13.022 | 36.095 | 4.615 | 0.787 | 0.309 | 0.944 | 383.234 | 458.565 | 18.630 | 51.639 |
| RFD700 | 14.496 | 0.800 | 0.032 | 0.956 | 398.964 | 498.436 | 13.020 | 36.089 | 6.543 | 0.797 | 0.255 | 0.949 | 339.286 | 411.534 | 16.823 | 46.631 |
Abbreviations in alphabetic order: CI = confidence interval; ICC = intra-class correlation coefficient; % MDD = minimal detectable difference as a percentage of the overall mean; N/s = newtons per second; RFD = rate of force development; RFD100 = rate of force development calculation when a window of 100 milliseconds was used; RFD200 = when a window of 200 milliseconds was used; RFD300 etc; % SEM = standard error of measurement as a percentage of the overall mean.