Table 4.
Intra-rater reliability and measurement error of commonly used clinical tests of the spine (continuous variables)
|
Examination (missing values) |
|
Measurement error |
Reliability |
||||
|---|---|---|---|---|---|---|---|
| Rater | Range (cm) | đ (cm) | LoA (cm) | SEoM | ICC [2, 1] (95% CI) | ||
|
General mobility |
|
|
|
|
|
|
|
| Lateral flexion FFD |
R (1) |
1 |
29.5, 58.0 |
1.53 |
-7.5, 10.5 |
3.3 |
0.77 (0.60, 0.88) |
| |
R |
2 |
36.0, 51.5 |
1.00 |
-5.7, 7.7 |
2.4 |
0.65 (0.41, 0.80) |
| |
L |
1 |
34.0, 57.0 |
0.56 |
-6.2, 7.3 |
2.4 |
0.84 (0.72, 0.91) |
| |
L |
2 |
34.5, 52.0 |
0.33 |
-6.7, 7.3 |
2.4 |
0.64 (0.40, 0.80) |
| Forward flexion FFD |
(1) |
1 |
0, 34.5 |
-0.77 |
-10.3, 8.7 |
3.4 |
0.89 (0.80, 0.94) |
| |
(3) |
2 |
0, 31.5 |
-0.06 |
-6.7, 6.6 |
2.3 |
0.94 (0.89, 0.97) |
| Schober test |
1* |
13.3, 15.5 |
0.03 |
-1.3, 1.3 |
0.4 |
0.53 (0.26, 0.73) |
|
| 2* | 13.0, 16.0 | -0.03 | -2.9, 2.8 | 1.0 | 0.14 (-0.21, 0.45) | ||
Range = lowest and highest measured value; đ = mean difference between ratings (systematic error); LoA = Limits of Agreement; SEoM = standard error of measurement; CI = confidence interval; FFD = finger-floor-distance; R = right; L = left; ICC = interclass correlation coefficient. *In the Schober test rater 1 rounded up/down to nearest half cm, rater 2 by fault to nearest whole cm. Clinically acceptable ICC in bold.