Table 3.
Bivariate data correlation as documented by Pearsons correlation coefficients for test repetition 1 versus 2, 2 versus 3, 3 versus 4, 4 versus 5 and 1 versus 5
| Measurements | Reference positions | |||||
|---|---|---|---|---|---|---|
| 1 vs. 2 (r) | 2 vs. 3 (r) | 3 vs. 4 (r) | 4 vs. 5 (r) | 1 vs. 5 (r) | ICC (R) | |
| “Finger–floor distance” | ||||||
| finger–floor distance (cm) | 0.993 | 0.993 | 0.997 | 0.994 | 0.971 | 0.997 |
| Schober’s sign (cm) | 0.983 | 0.994 | 0.987 | 0.992 | 0.966 | 0.996 |
| SLI LS (%) | 0.997 | 1.000 | 0.999 | 0.999 | 0.992 | 0.999 |
| Trunk inclination (°) | 0.992 | 0.990 | 0.990 | 0.994 | 0.943 | 0.995 |
| “Prone position” | ||||||
| SLI TS (%) | 0.809 | 0.772 | 0.950 | 0.964 | 0.921 | 0.975 |
| SLI LS (%) | 0.956 | 0.957 | 0.950 | 0.973 | 0.853 | 0.983 |
| Trunk inclination (°) | 0.876 | 0.961 | 0.961 | 0.964 | 0.811 | 0.981 |
| “Upright standing” | ||||||
| SLI CS (%) | 0.759 | 0.787 | 0.736 | 0.828 | 0.861 | 0.880 |
| SLI TS (%) | 0.910 | 0.845 | 0.839 | 0.869 | 0.897 | 0.975 |
| SLI LS (%) | 0.886 | 0.943 | 0.923 | 0.897 | 0.912 | 0.983 |
| Trunk inclination (°) | 0.943 | 0.967 | 0.966 | 0.985 | 0.918 | 0.981 |
| “70°-flexion” | ||||||
| Schober’s sign (cm) | 0.999 | 0.999 | 1.000 | 1.000 | 0.999 | 1.000 |
| SLI LS (%) | 0.965 | 0.999 | 1.000 | 1.000 | 0.965 | 0.994 |
| Trunk inclination (°) | – | – | – | – | – | – |
SLI sagittal length index
Every correlation coefficient yielded significant results (p < 0.05; n = 20). Test–retest reliability was rated by the interclass correlation coefficient (ICC). Each ICC yielded significant results (p < 0.05; n = 20)