Intra-Tester and Inter-Tester Reliability of the Lachmeter When Measuring Knee Joint Laxity
Table 3
Intra-tester reliability for measurements of anterior tibial translation (mm) in ACL patients (n = 6) performed on 2 separate days.
Tester
Grip
Leg
Dif. between day 1 and day 2 mean (SD) [95% CI]
Between test value
Average ICC [95% CI]
Interpretation of ICC
SEM
SDC
Tester 1
L grip
Non-dominant day 1 vs. 2
0.30 (1.28) [−1.04; 1.63]
0.59
0.80 [−0.21; 0.97]
Good reliability
0.57
1.59
Dominant day 1 vs. 2
0.59 (0.78) [−0.24; 1.41]
0.13
0.96 [0.74; 0.99]
Excellent reliability
0.16
0.43
AD grip
Non-dominant day 1 vs. 2
0.20 (0.72) [−0.56; 0.95]
0.53
0.96 [0.77; 0.99]
Excellent reliability
0.14
0.40
Dominant day 1 vs. 2
1.37 (1.58) [−0.29; 3.02]
0.09
0.82 [−0.09; 0.98]
Good reliability
0.67
1.86
L grip
Side-to-side day 1 vs. 2
0.49 (0.67) [−0.21; 1.20]
0.13
0.95 [0.69; 0.99]
Excellent reliability
0.15
0.42
AD grip
Side-to-side day 1 vs. 2
−0.47 (1.61) [−2.17; 1.23]
0.51
0.70 [−0.82; 0.96]
Moderate reliability
0.88
2.44
Tester 2
L grip
Non-dominant day 1 vs. 2
1.35 (1.42) [−0.14; 2.84]
0.07
0.77 [−0.35; 0.97]
Good reliability
0.68
1.89
Dominant day 1 vs. 2
−0.25 (1.54) [−1.86; 1.37]
0.71
0.92 [0.51; 0.99]
Excellent reliability
0.44
1.21
AD grip
Non-dominant day 1 vs. 2
0.58 (0.77) [−0.23; 1.39]
0.13
0.90 [0.38; 0.99]
Good reliability
0.24
0.67
Dominant day 1 vs. 2
−0.18 (0.80) [−1.02; 0.65]
0.60
0.97 [0.81; 0.99]
Excellent reliability
0.14
0.38
L grip
Side-to-side day 1 vs. 2
−0.44 (1.12) [−1.61; 0.74]
0.38
0.69 [−0.85; 0.95]
Moderate reliability
0.62
1.73
AD grip
Side-to-side day 1 vs. 2
0.14 (1.10) [−1.02; 1.29]
0.78
0.26 [−3.43; 0.89]
Poor reliability
0.95
2.62
L grip: Lachman grip; AD grip: anterior drawer grip; ICC: intra-class correlation coefficient; SEM: standard error of measurement. Anterior tibial translation was measured in mm, and the difference between day 1 and 2 is presented in ACL patients (n = 6). values correspond to the results from using Student’s paired t-test to test for differences between test 1 and test 2.
