Table 3 Association of age, BMI, gender, muscle strength and severity of knee OA with knee pain

Overall

 Age

1.01

0.996–1.02

0.1698

1.00

0.99–1.02

0.6107

 BMI

1.09

1.06–1.13

<0.0001

1.09

1.06–1.13

<0.0001

 Women (vs Men)

1.34

1.03–1.76

0.0299

1.35

1.03–1.78

0.0321

 Quadriceps muscle strength (5kgf increase)

0.87

0.82–0.92

<0.0001

0.88

0.82–0.93

<0.0001

 KL 2

1.3

0.96–1.75

0.0929

1.54

1.12–2.12

0.0083

 KL 3 or 4

3.77

2.79–5.10

<0.0001

4.49

3.31–6.10

<0.0001

Men

 Age

1.01

0.99–1.04

0.3309

1.01

0.99–1.04

0.3269

 BMI

1.09

1.02–1.17

0.013

1.09

1.02–1.18

0.0152

 Quadriceps muscle strength (5 kgf increase)

0.85

0.76–0.94

0.0019

0.86

0.77–0.96

0.0087

 KL 2

1.06

0.54–2.16

0.8753

1.18

0.60–2.21

0.624

 KL 3 or 4

5.98

3.42–10.54

<0.0001

4.99

2.79–8.93

<0.0001

Women

 Age

1.01

0.99–1.02

0.2416

1.00

9.99–1.02

0.945

 BMI

1.09

1.05–1.14

<0.0001

1.09

1.05–1.14

<0.0001

 Quadriceps muscle strength (5 kgf increase)

0.88

0.82–0.95

0.0007

0.89

0.82–0.96

0.003

 KL 2

1.33

0.95–1.89

0.1007

1.67

1.15–2.44

0.0068

 KL 3 or 4

3.24

2.28–4.64

<0.0001

3.37

3.12–6.44

<0.0001