Table 1 Between-group comparisons for demographic and kinematic data

Age (years)

34.4 ± 13.5^a

41.4 ± 12.6

p = .0001^b

BMI

23.6 ± 3.5

25.6 ± 4.9

p = .0001^b

Sex - % female

59%

57%

p = .8250

Pain intensity (0–10)

5.3 ± 1.5

not applicable

Activity limitation (0–100)

39 ± 21

not applicable

Kinematic parameters

No LBP (n = 124)

LBP (n = 140)

p-value

Flexion: Peak trunk flexion

Trunk flexion angular inclination (T12)

111^o ± 16^o

93^o ± 16^o

p < .0000^b

Flexion: Peak lumbar flexion

Lumbar ROM

52^o ± 11^o

46^o ± 12^o

p < .0000^b

Flexion: Peak pelvic flexion

Pelvic flexion angular inclination (S2)

59^o ± 15^o

48^o ± 15^o

p < .0000^b

Flexion: Lumbo-pelvic co-ordination

Mean Lumbar % contribution

48 ± 11%

49 ± 11%

p = .217

Flexion: Flexion Relaxation Response

A ratio formed by units of surface EMG activity

0.012 ± 0.32

0.25 ± 0.32

p < .0000^b

Sitting: Mean pelvic tilt range

Range from full anterior tilt to full posterior tilt

29^o ± 13^o

29^o ± 13^o

p = .883

Sitting: Mean pelvic tilt ratio

A ratio of pelvic tilt range/range of trunk ROM change

2.1 ± 1.3

2.4 ± 1.4

p = .064

Sitting: Mean relative sitting position

Max slump sit = 100%, maximum upright sit = 0%

48 ± 35%

50 ± 35%

p = .619

No LBP (n = 100)

LBP (n = 105)

Flexion: Delay at 0^o

Mean delay (negative numbers indicate pelvic delay)

−0.21 ± 0.46 s

−0.36 ± 0.46 s

p = .023^b

Flexion: Delay at 20^o

Mean delay (negative numbers indicate pelvic delay)

−0.30 ± 0.88 s

−0.51 ± 0.90s

p = .105

Flexion: Mean movement duration

Time from start of flexion to full flexion

2.28 ± 0.94 s

3.18 ± 0.94 s

p < .0000^b