Table 2.
Reliability indices of grip strength test
| Grip strength | n | The first test | The second test | Difference | Paired t | ICCa (95% CI) | SEMb | MDC95c | |
|---|---|---|---|---|---|---|---|---|---|
| mean ± SD (kg) | mean ± SD (kg) | mean ± SD (kg) | mean (95% CI) (kg) | P-value | |||||
| First trial (healthy) | 109 | 35.4 ± 10.7 | 35.4 ± 10.4 | 0.1 ± 3.8 | 0.1 (−0.7, 0.8) | 0.880 | 0.936 (0.908, 0.956) | 2.7 | 7.4 |
| Mean2d (healthy) | 109 | 34.6 ± 10.2 | 34.8 ± 10.1 | 0.2 ± 3.3 | 0.2 (−0.4, 0.8) | 0.503 | 0.949 (0.926, 0.965) | 2.3 | 6.4 |
| Mean3e (healthy) | 109 | 34.1 ± 9.9 | 34.3 ± 9.9 | 0.2 ± 3.0 | 0.2 (−0.4, 0.7) | 0.601 | 0.956 (0.936, 0.970) | 2.1 | 5.8 |
| First trial (injured) | 109 | 15.0 ± 11.5 | 15.8 ± 11.6 | 0.7 ± 3.8 | 0.7 (0.0, 1.4) | 0.052 | 0.945 (0.920, 0.962) | 2.7 | 7.4 |
| Mean2 (injured) | 109 | 15.1 ± 11.2 | 15.4 ± 11.4 | 0.4 ± 2.8 | 0.4 (−0.1, 0.9) | 0.140 | 0.970 (0.956, 0.979) | 2.0 | 5.4 |
| Mean3 (injured) | 109 | 15.1 ± 11.2 | 15.4 ± 11.3 | 0.4 ± 2.5 | 0.4 (−0.1, 0.8) | 0.143 | 0.974 (0.963, 0.982) | 1.8 | 5.0 |
| Mean3 (injured, ≤ 20 kg) | 76 | 8.9 ± 5.7 | 9.3 ± 6.1 | 0.4 ± 2.5 | 0.4 (−0.2, 1.0) | 0.145 | 0.908 (0.859, 0.941) | 1.8 | 4.9 |
| Mean3 (injured, > 20 kg) | 33 | 29.3 ± 6.6 | 29.5 ± 6.9 | 0.2 ± 2.6 | 0.2 (−0.7, 1.1) | 0.659 | 0.928 (0.859, 0.964) | 1.8 | 5.1 |
aIntraclass correlation coefficient
bStandard error measurement
cMinimal detectable change with 95% certainty
dMean of the first two trials
eMean of the three trials