Table 5 Static foot variables in participants with KOA (data reported as mean ± standard deviation)

Abourazzak et al., 2014 [18]

Prevalence of pes cavus (%)

Visual observation (FPI)- Barefoot

58

77

0.004*

Elbaz et al., 2017 [29]

Achilles tendon thickness (mm)

Digital caliper- Barefoot

17.1 ± 3.4

15.1 ± 3.1

0.009

Guler et al., 2009 [32]

Hallux valgus deformity (%)

Objective manual testing, radiography (x-ray)- Barefoot

22.60

No controls

NA

Hinman et al., 2016 [35]

FPI (n, %)

Visual observation (FPI)- Barefoot

Severely supinated

1 (1)

No controls

NA

Supinated

0 (0)

Normal

44 (54)

Pronated

30 (37)

Severely pronated

6 (7)

Levinger et al., 2010 [38]

Vertical navicular height

Objective manual testing, static footprint- Barefoot

0.23 ± 0.03

0.24 ± 0.03

0.542

Navicular drop

0.02 ± 0.01

0.03 ± 0.01

0.019*

Arch index

0.26 ± 0.04

0.22 ± 0.04

0.04*

Ohi et al., 2017 [43]

Hallux valgus angle (°)

3D footprint automatic (laser) measurement- Barefoot

13.6 ± 7.22

No controls

NA

Presence of hallux valgus (%)

12.5

Navicular height (mm)

30.1 ± 6.75

Calcaneus angle relative to floor (°)

1.35 ± 5.09

Rear foot angle (°)

6.01 ± 3.76

Reilly et al., 2006 [46]

Navicular height in sitting (cm)

Objective manual testing (goniometer)- Barefoot

5.22 ± 0.94

5.28 ± 0.89

0.005*

Navicular height in standing (cm)

4.69 ± 0.83

4.73 ± 0.98

0.003*

Reilly et al., 2009 [47]

FPI**

Visual observation (FPI)- Barefoot

7.0 (−2 to 10)**

1.0 (−4 to 8)**

< 0.001*

Ankle dorsiflexion during sitting (°)**

Objective manual testing using goniometer -Barefoot

9.0 (0 to 32)**

7.5 (0 to 15)**

< 0.001*

Shakoor et al., 2008 [51]

VPT (volts)

Biothesiometer, AP radiography- Barefoot

First MTPJ

15 ± 9.9

6.4 ± 3.3

< 0.001*

Medial malleolus

22 ± 11.7

12.3 ± 5.2

0.001*

Lateral malleolus

22.3 ± 10.5

10.4 ± 3.2

< 0.001*

Tan et al., 2020 [53]

FPI

Visual observation (FPI)-

Midfoot and arch height mobility/arch indices- Barefoot

3 (1 to 7)

No controls

NA

Arch height difference (mm)

8.8 ± 5.2

Midfoot width difference (mm)

8.9 ± 3.1

Foot mobility magnitude (mm)

14.8 ± 7.9

Van Tunen et al., 2018 [55]

FPI (n, %)

Visual observation (FPI)- Barefoot

Foot mobility magnitude calculation

Navicular drop test

Normal (scores 0 to + 5)

9 (43)

No controls

NA

Pronated (scores + 6 to + 9)

11 (52)

Highly pronated (scores greater + 9)

1 (5)

Foot mobility magnitude (mm)

9.6 ± 3.8

Navicular drop (mm)

7.6 ± 3.1