Table 3 Portable ultrasonographic medial clear space measurements during the gravity stress test, weightbearing, and the external rotation stress test comparing between stage III vs. IVb and between stage IVa vs. IVb in the sequentially created SER ankle injury model

GST-N

III

6.5

(5.7–6.7)

0.020

6.5

(5.9–7.6)

0.031

9.8

(9.5–10.8)

0.028

IVa

7.4

(6.6–8.3)

0.015

6.5

(5.7–6.3)

0.019

11.3

(10.9–12.5)

0.020

IVb

12.3

(10.5–14.4)

Ref

13.5

(11.5–16.0)

Ref

15.6

(14.3–18.3)

Ref

GST-PF

III

6.4

(5.1–7.7)

0.020

6.6

(5.5–7.7)

0.031

10.7

(9.7–11.9)

0.031

IVa

6.6

(6.4–7.4)

0.015

6.9

(6.0-8.7)

0.026

11.4

(10.0-12.4)

0.026

IVb

13.1

(12.1–14.6)

Ref

12.4

(11.3–12.6)

Ref

19.0

(16.5–21.6)

Ref

Weight

bearing

III

3.4

(2.9-4.0)

0.031

3.5

(2.3–4.2)

0.047

5.5

(5.3–6.2)

0.031

IVa

3.6

(3.1–4.5)

0.083

4.3

(3.2–5.5)

0.28

5.6

(4.3–6.8)

0.14

IVb

4.9

(4.5–5.7)

Ref

5.2

(4.4–5.5)

Ref

7.4

(5.6–8.4)

Ref

ER stress test

III

8.4

(7.5–10.0)

0.025

8.4

(7.6–9.8)

0.021

15.7

(13.3–16.2)

0.015

IVa

10.3

(8.3–11.0)

0.028

10.2

(8.3–10.5)

0.022

15.8

(14.9–18.2)

0.010

IVb

12.4

(10.0-16.5)

Ref

12.8

(10.8–15.6)

Ref

20.1

(19.3–22.5)

Ref