Immediately post-fitting

6 months after fitting

VAS

at rest

VAS on

mobilization

VAS at rest

VAS on

mobilization

Median gain ± SD

−1 ± 1

−2 ± 1

1 ± 1

2 ± 2.031

Minimal gain

−5

−5

−2

−5

Maximal gain

3

4

4

3

p

0.014*

<0.001**

0.001**

0.002**