Intra-Tester and Inter-Tester Reliability of the Lachmeter When Measuring Knee Joint Laxity
Table 2
Intra-tester reliability for measurements of anterior tibial translation (mm) in healthy subjects (n = 23) 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
0.17 (1.00) [−0.27; 0.60]
0.44
0.83 [0.61; 0.93]
Good reliability
0.41
1.14
Dominant day 1 vs. 2
−0.01 (0.91) [−0.40; 0.38]
0.96
0.87 [0.69; 0.94]
Good reliability
0.33
0.91
AD grip
Non-dominant day 1 vs. 2
0.41 (1.68) [−0.32; 1.14]
0.26
0.71 [0.33; 0.88]
Moderate reliability
0.90
2.50
Dominant day 1 vs. 2
0.48 (1.52) [−0.18; 1.14]
0.14
0.59 [0.05; 0.83]
Moderate reliability
0.97
2.70
L grip
Side-to-side day 1 vs. 2
0.42 (1.08) [−0.05; 0.88]
0.08
0.17 [−0.91; 0.65]
Poor reliability
0.98
2.73
AD grip
Side-to-side day 1 vs. 2
0.11 (0.93) [−0.29; 0.51]
0.58
0.68 [0.26; 0.86]
Moderate reliability
0.53
1.46
Tester 2
L grip
Non-dominant day 1 vs. 2
−0.79 (0.95) [−1.20; −0.37]
<0.001
0.68 [0.25; 0.86]
Moderate reliability
0.54
1.49
Dominant day 1 vs. 2
−0.97 (1.10) [−1.45; −0.49]
<0.001
0.62 [0.11; 0.84]
Moderate reliability
0.68
1.88
AD grip
Non-dominant day 1 vs. 2
−0.58 (1.39) [−1.18; 0.02]
0.06
0.72 [0.34; 0.88]
Moderate reliability
0.74
2.04
Dominant day 1 vs. 2
−0.50 (1.50) [−1.15; 0.15]
0.13
0.70 [0.31; 0.87]
Moderate reliability
0.82
2.28
L grip
Side-to-side day 1 vs. 2
0.26 (0.91) [−0.13; 0.65]
0.18
0.13 [−1.02; 0.63]
Poor reliability
0.85
2.35
AD grip
Side-to-side day 1 vs. 2
−0.42 (1.01) [−0.86; 0.02]
0.06
−0.28 [−1.98; 0.45]
Poor reliability
1.14
3.17
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 healthy subjects (n = 23). values correspond to the results from using Student’s paired t-test to test for differences between test 1 and test 2.
