Table 2.
Interventional changes in strength and fatigue development.
| Difference from baseline to follow-up | Between group difference at follow-up | Group by time | |||
|---|---|---|---|---|---|
| Strength training | Ergonomic training (usual care) | Strength versus ergonomic | P value | P value | |
| Hand grip MVC | |||||
| Strength (Newton) | 43 (5 to 81) | −61 (−96 to −26) | 107 (69 to 144) | <0.0001 | <0.0001 |
| Extensor peak EMG (mV) | 23 (−3 to 49) | −1 (−26 to 23) | 25 (−2 to 52) | 0.06 | 0.18 |
| Flexor peak EMG (mV) | 1 (−40 to 43) | −2 (−39 to 35) | 3 (−39 to 45) | 0.89 | 0.90 |
| Fatigue test | |||||
| Time to fatigue (sec) | 23.5 (14.6 to 32.5) | −7.0 (−96.9 to 82.7) | 24.0 (14.6 to 33.4) | <0.0001 | <0.001 |
| Impulse (Ns) | 6470 (4308 to 8633) | 304 (−1883 to 2492) | 6516 (4245 to 8787) | <0.0001 | <0.001 |
| Extensor peak EMG (mV) | 47 (16 to 77) | −11 (−43 to 20) | 62 (30 to 95) | <0.001 | <0.01 |
| Flexor peak EMG (mV) | −3 (−55 to 49) | −3 (−57 to 51) | −1 (−58 to 56) | 0.98 | 0.99 |
| Extensor mean EMG (mV) | 26 (3 to 49) | −8 (−32 to 16) | 36 (11 to 61) | <0.01 | <0.05 |
| Flexor mean EMG (mV) | −13 (−54 to 27) | 2 (−40 to 44) | −18 (−62 to 26) | 0.41 | 0.60 |
| MPF extensor (Hz) | −7 (−13 to −2) | 0 (−6 to 6) | −7 (−13 to −1) | <0.05 | 0.08 |
| MPF flexor (Hz) | −5 (−13 to 3) | −4 (−12 to 5) | −2 (−11 to 7) | 0.63 | 0.79 |
Changes in handgrip and fatigue test performance from baseline to 10-week follow-up. Associated changes in electromyography (EMG) are also illustrated. Differences of each group are illustrated on the left, and contrasts between the groups at follow-up in the middle. P values for the group by time interactions are shown on the right. MPF denotes “median power frequency.” Values are means (95% confidence interval).