Table 2.
Before and after muscle-damaging eccentric exercise, changes in muscle activation and motor unit behavior during submaximal trapezoid contractions test at 30% and 50% MVIC.
| Initial bout |
Second bout |
||||
|---|---|---|---|---|---|
| Pre | Post | Pre | Post | ||
| EMG amplitude (30%) | |||||
| (V) | EF group | 0.24 ± 0.10 | 0.66 ± 0.23# | 0.28 ± 0.09 | 0.43 ± 0.19∗# |
| IA group | 0.40 ± 0.05 | 0.49 ± 0.13 | 0.38 ± 0.16 | 0.51 ± 0.21 | |
| EMG amplitude (50%) | |||||
| (V) | EF group | 0.47 ± 0.15 | 0.82 ± 0.24 | 0.61 ± 0.19 | 0.90 ± 0.23 |
| IA group | 0.67 ± 0.12 | 0.71 ± 0.16 | 0.64 ± 0.20 | 0.72 ± 0.20 | |
| Slope coefficient (30%) | |||||
| (RT vs. MFR) | EF group | −0.52 ± 0.37 | −1.11 ± 0.42 | −0.73 ± 0.37 | −1.02 ± 0.26 |
| (pps) | IA group | −0.63 ± 0.33 | −0.93 ± 0.32 | −0.53 ± 0.28 | −0.88 ± 0.40 |
| y-intercept (30%) | |||||
| (RT vs. MFR) | EF group | 24.52 ± 8.75 | 35.46 ± 13.26 | 29.04 ± 10.08 | 35.73 ± 8.02 |
| (pps) | IA group | 20.74 ± 7.57 | 24.26 ± 6.67 | 18.92 ± 5.65 | 23.39 ± 2.80 |
| Slope coefficient (50%) | |||||
| (RT vs. MFR) | EF group | −0.63 ± 0.22 | −1.00 ± 0.59 | −0.65 ± 0.20 | −0.73 ± 0.32 |
| (pps) | IA group | −0.55 ± 0.37 | −0.65 ± 0.15 | −0.59 ± 0.35 | −0.45 ± 0.17 |
| y-intercept (50%) | |||||
| (RT vs. MFR) | EF group | 33.61 ± 6.51 | 37.85 ± 13.21 | 37.14 ± 10.37 | 32.73 ± 9.90 |
| (pps) | IA group | 24.79 ± 9.87 | 25.74 ± 6.77 | 26.53 ± 12.01 | 22.77 ± 6.48 |
| Slope coefficient (50%) | |||||
| (RT vs. DT) | EF group | 1.26 ± 0.45 | 1.51 ± 0.66 | 1.80 ± 0.65 | 1.16 ± 0.63 |
| (% MVIC DT) | IA group | 1.08 ± 0.40 | 1.22 ± 0.48 | 0.84 ± 0.17 | 0.86 ± 0.32 |
| y-intercept (50%) | |||||
| (RT vs. DT) | EF group | −16.73 ± 15.09 | −12.45 ± 15.26 | −38.73 ± 29.95 | −5.03 ± 16.39 |
| (% MVIC DT) | IA group | −3.65 ± 11.24 | 0.93 ± 7.95 | 3.37 ± 8.29 | 9.37 ± 12.63 |
Values are means ± SD. MVIC: maximal voluntary isometric contraction, EF: elbow flexion, IA: index finger abductor, EMG: electromyography, RT: recruitment threshold, MFR: mean firing rate, DT: derecruitment threshold, V: volte, pps: pulses per second. ∗ indicated significant difference between bout 1 and bout 2 at Post. # indicated significant difference between Pre and Post.