Table 2.
Validity of the Jump-MVC method for assessment of the force–velocity profile in squat jump.
| Mean scores | Intra-class correlation | Within-individual error | Systematic error | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Multiple-point method | Jump-MVC | ICCs | ICCa | SEM | CV% | t | Sig | ES | |
| MVC Angle 30° | |||||||||
| F0 (N) | 2244.2 ± 418.8 | 2962.4 ± 639.3 | 0.402 (− 0.093–0.760) | 0.570 (− 0.206–0.864) | 269.1 | 10.34 (8.07–14.38) | − 9.44 | 0.000 | 0.79 |
| V0 (m/s) | 2.40 ± 0.51 | 1.84 ± 0.34 | 0.365 (− 0.106–0.719) | 0.530 (− 0.237–0.837) | 0.25 | 11.75 (9.18–16.35) | 7.95 | 0.000 | 0.72 |
| Pmax (W) | 1330.3 ± 304.5 | 1346.6 ± 310.9 | 0.949 (0.888–0.977) | 0.970 (0.941–0.988) | 70.2 | 5.24 (4.095–7.30) | − 0.82 | 0.418 | 0.03 |
| F–V slope | − 984.0 ± 297.3 | − 1674.6 ± 498.2 | 0.261 (− 0.089–0.628) | 0.410 (− 0.194–0.772) | 250.7 | − 18.8 (− 14.7 to − 26.2) | 9.74 | 0.000 | 0.80 |
| MVC Angle 60° | |||||||||
| F0 (N) | 2244.2 ± 418.8 | 2691.8 ± 627.0 | 0.481 (− 0.035–0.769) | 0.640 (− 0.073–0.869) | 318.3 | 12.92 (10.07–17.93) | − 4.97 | 0.000 | 0.51 |
| V0 (m/s) | 2.40 ± 0.51 | 2.02 ± 0.49 | 0.440 (0.006–0.723) | 0.610 (0.011–0.839) | 0.33 | 15.01 (11.72–20.82) | 4.02 | 0.000 | 0.40 |
| Pmax (W) | 1330.3 ± 304.5 | 1329.5 ± 313.1 | 0.950 (0.890–0.978) | 0.970 (0.942–0.989) | 70.5 | 5.3 (4.14–7.38) | 0.04 | 0.970 | 0.00 |
| F–V slope | − 984.0 ± 297.3 | − 1422.8 ± 508.1 | 0.330 (− 0.087–0.653) | 0.490 (− 0.190–0.790) | 292.4 | − 24.30 (− 18.97 to − 33.81) | 5.30 | 0.000 | 0.54 |
| MVC Angle 90° | |||||||||
| F0 (N) | 2244.2 ± 418.8 | 1673.3 ± 278.6 | 0.305 (− 0.085–0.681) | 0.460 (− 0.185–0.810) | 196.4 | 10.028 (7.83–13.95) | 10.28 | 0.000 | 0.81 |
| V0 (m/s) | 2.40 ± 0.51 | 4.48 ± 2.51 | 0.089 (− 0.140–0.374) | 0.160 (− 0.326–0.544) | 1.68 | 48.75 (38.062–67.81) | − 4.4 | 0.000 | 0.45 |
| Pmax (W) | 1330.3 ± 304.5 | 1830.2 ± 873.2 | 0.322 (− 0.040–0.622) | 0.480 (− 0.084–0.767) | 502.9 | 31.83 (24.85–44.28) | − 3.51 | 0.002 | 0.34 |
| F–V slope | − 984.0 ± 297.3 | − 450.3 ± 182.8 | 0.131 (− 0.074–0.428) | 0.230 (− 0.161–0.599) | 185.3 | − 25.85 (− 20.18 to − 35.96) | − 10.2 | 0.000 | 0.81 |
| MVC Angle: Mean of 30°, 60° and 90° angles | |||||||||
| F0 (N) | 2244.2 ± 418.8 | 2442.5 ± 489.8 | 0.725 (0.349–0.883) | 0.840 (0.517–0.938) | 210.0 | 8.96 (7.00–12.47) | − 3.34 | 0.003 | 0.32 |
| V0 (m/s) | 2.40 ± 0.51 | 2.18 ± 0.50 | 0.565 (0.218–0.783) | 0.720 (0.358–0.878) | 0.31 | 13.76 (10.74–19.14) | 2.48 | 0.021 | 0.20 |
| Pmax (W) | 1330.3 ± 304.5 | 1311.7 ± 309.5 | 0.955 (0.902–0.980) | 0.970 (0.949–0.990) | 64.9 | 4.92 (3.84–6.84) | 1.01 | 0.324 | 0.04 |
| F–V slope | − 984.0 ± 297.3 | − 1182.6 ± 363.4 | 0.570 (0.131–0.803) | 0.720 (0.232–0.891) | 192.3 | − 17.76 (− 13.86 to − 24.70) | 3.65 | 0.001 | 0.36 |
F0—maximal isometric force; V0—maximal theoretical velocity; Pmax—maximal power; MVC—maximal voluntary contraction; ICCs—single measures intra-class correlation coefficient; ICCa—average measures intra-class correlation coefficient; SEM—standard error of measurement; CV%—coefficient of variation; ES—Effect size (Cohen’s d); Note that for the two-point methods, the F0 is the actual maximal isometric force (i.e. recorded during maximal voluntary contraction).