Table 1 Inter and intra-agreement correlation using isolated measurement comparison or the average of three measurements comparison

Spring Ligament

 Normal

0.77 [0.68–0.85]

0.82 [0.75–0.89]

0.85 [0.76–0.91]

0.87 [0.82–0.93]

0.88 [0.78–0.93]

 Valgus 20°

0.82 [0.74–0.89]

0.79 [0.71–0.86]

0.89 [0.82–0.94]

0.84 [0.75–0.91]

0.87 [0.77–0.93]

 Varus 30°

0.87 [0.82–0.92]

0.88 [0.82–0.92]

0.92 [0.87–0.95]

0.94 [0.90–0.96]

0.94 [0.88–0.97]

Posterior tibial tendon

 Normal

0.66 [0.55–0.77]

0.69 [0.58–0.79]

0.76 [0.64–0.86]

0.85 [0.76–0.91]

0.78 [0.62–0.88]

 Valgus 20°

0.64 [0.53–0.75]

0.59 [0.47–0.71]

0.77 [0.65–0.86]

0.67 [0.52–0.80]

0.63 [0.41–0.79]

 Varus 30°

0.62 [0.51–0.74]

0.59 [0.47–0.72]

0.74 [0.61–0.84]

0.70 [0.55–0.81]

0.86 [0.76–0.93]