Table 3. Inter-set reliability of the mean and peak EMGRMS variables.
| Concentric | Eccentric | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| muscle | Load (kg·m2) | EMGRMS | Avg ± SD (%MVC) | Range (%MVC) | TE (%MVC) | CV (%) | ICC2.1 | t-test sig. | Avg ± SD (%MVC) | Range (%MVC) | TE (%MVC) | CV (%) | ICC2.1 | t-test sig. |
| sol | 0.05 | Mean | 41.7 ± 25.4 | 2.8–92.4 | 8.9 | 21.4 | 0.879 | 0.420 | 29.6 ± 16.4 | 2.1–77.1 | 6.5 | 21.8 | 0.843 | 0.276 |
| Peak | 57.7 ± 33.9 | 3.2–133.4 | 11.2 | 11.4 | 0.966 | 0.072 | 46.5 ± 26.2 | 2.5–110.1 | 10.5 | 12.9 | 0.952 | 0.655 | ||
| 0.125 | Mean | 41.1 ± 27.2 | 2.9–109.3 | 4.7 | 21.1 | 0.861 | 0.044 | 38.8 ± 23.7 | 2.4–87.2 | 5 | 17.0 | 0.908 | 0.087 | |
| Peak | 54.3 ± 34.9 | 3.5–137.6 | 8.8 | 19.3 | 0.883 | 0.027 | 63.5 ± 43.6 | 2.9–177.7 | 10.6 | 22.5 | 0.844 | 0.603 | ||
| 0.225 | Mean | 33.1 ± 18.4 | 2.5–74.7 | 7 | 16.3 | 0.926 | 0.742 | 40.6 ± 23.5 | 2.6–86.8 | 6.9 | 16.8 | 0.942 | 0.102 | |
| Peak | 45 ± 23.7 | 3.4–93.9 | 10.5 | 23.3 | 0.811 | 0.828 | 61 ± 38.6 | 3.2–162.3 | 10.8 | 17.7 | 0.923 | 0.409 | ||
| l.gas | 0.05 | Mean | 13.9 ± 12.7 | 0.6–47.1 | 2.7 | 19.7 | 0.950 | 0.082 | 11.9 ± 10.5 | 0.5–41.5 | 3.6 | 30.1 | 0.889 | 0.845 |
| Peak | 19.1 ± 16.5 | 0.8–60.1 | 4.2 | 19.6 | 0.918 | 0.051 | 17.7 ± 16.3 | 0.7–70.8 | 7.2 | 14.8 | 0.943 | 0.501 | ||
| 0.125 | Mean | 12.9 ± 9.4 | 0.9–43.2 | 2.5 | 22.2 | 0.916 | 0.044 | 12.5 ± 9 | 0.7–37.3 | 1.9 | 28.3 | 0.890 | 0.003 | |
| Peak | 17.9 ± 13 | 1.2–61.1 | 5.2 | 21.8 | 0.929 | 0.025 | 20.7 ± 16.7 | 0.8–73.1 | 4.6 | 40.4 | 0.812 | 0.035 | ||
| 0.225 | Mean | 12.1 ± 9.1 | 1.7–36.1 | 2.7 | 29.0 | 0.818 | 0.633 | 14 ± 11.8 | 2–51.9 | 4 | 22.0 | 0.915 | 0.626 | |
| Peak | 17.1 ± 12.9 | 2–46.7 | 3.4 | 20.1 | 0.928 | 0.196 | 21.2 ± 18.7 | 2.5–86.8 | 7.1 | 33.6 | 0.859 | 0.840 | ||
| semi | 0.05 | Mean | 27.6 ± 17.3 | 4.1–73.1 | 4.3 | 15.7 | 0.939 | 0.715 | 27.2 ± 23.2 | 2.8–134.2 | 6.5 | 24.0 | 0.923 | 0.694 |
| Peak | 41.9 ± 29.5 | 4.6–124.8 | 9.7 | 15.9 | 0.941 | 0.970 | 42.7 ± 45.5 | 3.7–294.5 | 20 | 15.8 | 0.950 | 0.362 | ||
| 0.125 | Mean | 25 ± 16.6 | 4.8–62.4 | 4 | 17.0 | 0.959 | 0.147 | 30.3 ± 21.2 | 6.1–97.1 | 4.8 | 14.9 | 0.944 | 0.406 | |
| Peak | 42.1 ± 34.3 | 6.7–121.3 | 8.3 | 23.1 | 0.896 | 0.718 | 49.5 ± 38.3 | 7.4–185.4 | 13.8 | 46.8 | 0.807 | 0.155 | ||
| 0.225 | Mean | 23.1 ± 19.6 | 4.3–112.8 | 3.9 | 19.8 | 0.943 | 0.289 | 26.5 ± 16.5 | 5.2–68.6 | 3.9 | 27.8 | 0.866 | 0.624 | |
| Peak | 37.9 ± 48.9 | 5.5–315.1 | 16.7 | 43.9 | 0.884 | 0.300 | 41.1 ± 28.2 | 6.9–132.1 | 7.8 | 18.9 | 0.927 | 0.808 | ||
| bf | 0.05 | Mean | 21.4 ± 14.5 | 2.1–74.4 | 2.6 | 11.9 | 0.962 | 0.013 | 16.8 ± 10.7 | 3.1–49.8 | 3.5 | 20.6 | 0.898 | 0.583 |
| Peak | 33 ± 25.9 | 3.2–134.6 | 4.4 | 16.9 | 0.923 | 0.013 | 29.6 ± 27 | 4–145.1 | 7.3 | 16.0 | 0.948 | 0.423 | ||
| 0.125 | Mean | 19.5 ± 11.7 | 2.3–54.8 | 3.3 | 14.7 | 0.945 | 0.550 | 23.5 ± 16.6 | 3.3–79.5 | 3.8 | 16.6 | 0.944 | 0.234 | |
| Peak | 27.3 ± 16.4 | 3.3–81.5 | 6.6 | 13.4 | 0.964 | 0.752 | 40.6 ± 28.7 | 4.4–140.7 | 8.9 | 24.8 | 0.927 | 0.302 | ||
| 0.225 | Mean | 16.8 ± 10.3 | 1.5–47.2 | 2.5 | 24.3 | 0.841 | 0.632 | 24.1 ± 16.7 | 1.8–76.3 | 4 | 21.8 | 0.904 | 0.839 | |
| Peak | 23.8 ± 14.6 | 2.6–55.9 | 3.6 | 15.1 | 0.940 | 0.259 | 39.5 ± 28.6 | 3.4–127.6 | 9.6 | 24.3 | 0.890 | 0.550 | ||
| vm | 0.05 | Mean | 53.3 ± 19.4 | 10.3–88.3 | 5.3 | 10.0 | 0.902 | 0.004 | 34.4 ± 13.7 | 10.9–70.8 | 4.9 | 14.2 | 0.876 | 0.850 |
| Peak | 68.8 ± 22.6 | 10.9–106.1 | 7.1 | 16.9 | 0.811 | 0.051 | 57.7 ± 20.2 | 13–99.4 | 6.6 | 16.7 | 0.761 | 0.471 | ||
| 0.125 | Mean | 64.2 ± 24.7 | 9.3–109.1 | 10.9 | 11.7 | 0.919 | 0.567 | 42.3 ± 14.9 | 12.9–76.2 | 7.1 | 10.4 | 0.844 | 0.086 | |
| Peak | 83.6 ± 32.7 | 11.4–162.9 | 14.6 | 10.3 | 0.892 | 0.231 | 75.6 ± 28.1 | 15.7–147 | 13.4 | 11.4 | 0.896 | 0.129 | ||
| 0.225 | Mean | 54.3 ± 21.9 | 11.4–117.4 | 6.3 | 17.5 | 0.796 | 0.867 | 49.4 ± 14.6 | 14.4–88.5 | 5.1 | 17.8 | 0.761 | 0.006 | |
| Peak | 78.9 ± 28.6 | 14.9–159.8 | 8.2 | 10.4 | 0.918 | 0.341 | 77.4 ± 25.7 | 16.4–148 | 9.1 | 11.8 | 0.868 | 0.117 | ||
| vl | 0.05 | Mean | 56.4 ± 24.9 | 2.5–112.3 | 10.3 | 18.3 | 0.828 | 0.341 | 37 ± 19.5 | 1.6–104.5 | 5.3 | 14.2 | 0.924 | 0.137 |
| Peak | 77.1 ± 34.1 | 2.9–157.4 | 13.6 | 9.4 | 0.901 | 0.684 | 61.1 ± 27.7 | 2.4–129.5 | 7.2 | 14.9 | 0.806 | 0.146 | ||
| 0.125 | Mean | 65.3 ± 20.3 | 17.8–104 | 6.2 | 12.7 | 0.924 | 0.090 | 45.3 ± 16.8 | 19.8–95.5 | 6.7 | 16.4 | 0.757 | 0.010 | |
| Peak | 88 ± 29.1 | 24.3–153.3 | 10.2 | 17.6 | 0.845 | 0.063 | 79 ± 28.7 | 26.4–158.6 | 11.6 | 11.8 | 0.929 | 0.010 | ||
| 0.225 | Mean | 51.9 ± 23.5 | 8.6–111.8 | 6.6 | 11.6 | 0.866 | 0.628 | 47.3 ± 16.8 | 8–94.4 | 7.8 | 14.7 | 0.801 | 0.024 | |
| Peak | 79.2 ± 34 | 11.4–160.4 | 10.7 | 13.5 | 0.884 | 0.024 | 75.6 ± 31.1 | 10.7–168 | 11.6 | 15.3 | 0.850 | 0.073 | ||
| rf | 0.05 | Mean | 49.5 ± 25.9 | 4.1–132 | 16.3 | 32.9 | 0.568 | 0.033 | 33.6 ± 22.2 | 5.1–129.9 | 14.2 | 42.4 | 0.579 | 0.187 |
| Peak | 71.3 ± 38.1 | 5.2–184.4 | 21.9 | 16.6 | 0.828 | 0.055 | 57 ± 32.8 | 6.3–186.2 | 21 | 26.1 | 0.613 | 0.056 | ||
| 0.125 | Mean | 61.6 ± 26.6 | 10–119.6 | 10.2 | 15.6 | 0.895 | 0.021 | 32.3 ± 14.5 | 11.2–72.7 | 8.4 | 18.5 | 0.824 | 0.014 | |
| Peak | 85.8 ± 40.1 | 17.7–181.6 | 15.6 | 30.7 | 0.645 | 0.020 | 65.9 ± 33.7 | 18.2–183.2 | 17.1 | 36.8 | 0.565 | 0.017 | ||
| 0.225 | Mean | 43.4 ± 20.7 | 5.4–99 | 6.8 | 18.2 | 0.824 | 0.572 | 33.4 ± 15.7 | 7.9–84.3 | 6.2 | 26.0 | 0.702 | 0.032 | |
| Peak | 69.9 ± 31.5 | 13.1–145.5 | 10.1 | 14.5 | 0.898 | 0.446 | 62.3 ± 27.1 | 13.6–136.5 | 9.9 | 15.9 | 0.860 | 0.128 | ||
| glut | 0.05 | Mean | 58.4 ± 21.3 | 20.2–101.9 | 10 | 17.1 | 0.782 | 0.463 | 34.3 ± 15 | 10.7–70.7 | 8 | 23.5 | 0.707 | 0.220 |
| Peak | 90.6 ± 38.1 | 24–202.3 | 16.9 | 15.9 | 0.990 | 0.471 | 65.8 ± 33.9 | 18.1–181 | 17.2 | 12.0 | 0.961 | 0.929 | ||
| 0.125 | Mean | 63.8 ± 102.3 | 19.5–585.5 | 10.2 | 48.0 | 0.642 | 0.266 | 64.8 ± 43.1 | 24–252 | 7.8 | 39.5 | 0.537 | 0.017 | |
| Peak | 105.7 ± 173.6 | 26.2–990.4 | 17.6 | 18.7 | 0.805 | 0.133 | 113.2 ± 61.2 | 40.3–363.8 | 17.3 | 26.2 | 0.748 | 0.030 | ||
| 0.225 | Mean | 39.9 ± 31.7 | 14.8–233.1 | 19.1 | 16.6 | 0.989 | 0.668 | 66.6 ± 39 | 22.9–303.5 | 26.3 | 15.3 | 0.908 | 0.183 | |
| Peak | 61 ± 47.3 | 24.5–347.2 | 27.7 | 45.3 | 0.665 | 0.628 | 106.4 ± 84.9 | 36.4–646.9 | 60.8 | 57.2 | 0.485 | 0.279 | ||
Note: Load, Flywheel load; sol, m. soleus; l.gas, m. gastrochnemius lateralis; bf, m. biceps femoris; semi, m. semimembranosus; vm, m. vastus medialis; vl, m. vastus lateralis; rf, m. rectus femoris; glut; m. gluteus maximus; EMGRMS, root-mean-square of the EMG signal, ICC2.1, Two-way random, single measures, absolute agreement Intra-class correlation coefficient model;; concentric, propulsive part of the squat; eccentric, braking part of the squat; 1./3mean, 2./3mean, 3./3mean, mean EMG activity in the first (1./3mean), second (2./3mean) and third (3./3mean) part of vertical displacement length during the squat derived from the position-time data.