Table 1

Baseline characteristics of participants by group

Motion control shoes
(n=18)
Neutral shoes
(n=22)
Age (years)64.6 (7.2)64.2 (7.2)
Gender, n (%)
 Female11 (61)13 (59)
 Male7 (39)9 (41)
Symptom duration (years)11.6 (7.8)11.1 (8.0)
Height (m)1.7 (0.1)1.7 (0.1)
Body mass (kg), median (IQR)89 (75–95)89 (81–106)
Body mass index (kg/m2), median (IQR)31.4 (27.6–35.4)31.2 (27.8–33.9)
Unilateral knee osteoarthritis symptoms, n (%)3 (17)7 (32)
Radiographic disease severity, n (%)*
 Grade 2 (mild)2 (11)3 (14)
 Grade 3 (moderate)8 (44)10 (45)
 Grade 4 (severe)8 (44)9 (41)
Radiographic knee alignment (degrees)†188.7 (6.3)188.1 (5.5)
Foot Posture Index classification, n (%)‡
 Supinated0 (0)1 (5)
 Neutral3 (17)8 (36)
 Pronated15 (83)13 (59)
Foot mobility magnitude (mm)§7.7 (3.5)7.7 (2.5)
Navicular drop (mm)§6.5 (4.4)6.3 (3.0)
Currently employed, n (%)10 (56)11 (50)
Current drug/supplement use, n (%)¶15 (83)18 (82)
 Paracetamol combinations11 (61)15 (68)
 Non-steroidal anti-inflammatories8 (44)10 (45)
 Topical anti-inflammatories8 (44)4 (18)
 Oral corticosteroids0 (0)0 (0)
 Oral opioids0 (0)0 (0)
Arthritis Self-Efficacy Scale**6.4 (2.1)6.3 (1.5)
Cointerventions used in the last 6 months, n (%)
 Land-based exercise12 (67)13 (59)
 Heat/cold treatment11 (61)7 (32)
 Massage8 (44)11 (50)
 Knee braces8 (44)8 (36)
 Manual therapy3 (17)8 (36)
 Orthotics/arch supports2 (11)2 (9)
 Hydrotherapy3 (17)4 (18)
Usual shoes overall motion control feature score, mean (SD)††6.2 (3.2)6.4 (2.7)
Expectation of treatment, before randomisation, n (%)
 No change0 (0)0 (0)
 Mild improvement2 (11)3 (14)
 Moderate improvement10 (56)16 (73)
 Large improvement6 (33)3 (14)
 Complete recovery0 (0)0 (0)
Expectation of treatment, after shoe allocation, n (%)
 No change0 (0)0 (0)
 Mild improvement1 (6)2 (9)
 Moderate improvement12 (67)13 (59)
 Large improvement5 (28)6 (27)
 Complete recovery0 (0)1 (5)
  • Data reported as mean (SD) unless otherwise stated.

  • IQR in 25th–75th percentile.

  • *Using the Kellgren and Lawrence grading system.

  • †Measured as anatomical axis from standing radiograph, with 180° indicating neutral alignment, <180° varus alignment and >180° valgus alignment.

  • ‡Scored from −12 to 12; scores <0 indicate supinated foot posture, 0–5 neutral foot posture and >5 pronated foot posture.

  • §Higher values indicate greater mobility/drop.

  • ¶Defined as at least once per week in the last 6 months.

  • **Scores range 1–10, with higher scores indicating higher self-efficacy.

  • ††Measured using the Footwear Assessment Tool; scores range 0–11, with higher scores indicating more motion control features.