Table 4 Timing and sitting parameters

Delay at 0^o

Mean delay (negative numbers indicate pelvic delay)

-0.21 ± 0.46 s

-0.36 ± 0.46 s

p = .023

**β = − 0.15 (− 0.28, − 0.21)

 Pelvic delay at onset of movement (10th centile, > 0.53 s)

Number (%) of people with pelvic delay > 0.53 s

10 (10%)

19(18%)

NS

*Prevalence ratio

–

2.0 (0.9–3.3)

 Lumbar delay at onset of movement (90th centile, > 0 s)

Number (%) of people with lumbar delay > 0 s

11 (11%)

10 (10%)

NS

Prevalence ratio

–

1.1 (0.04–0.8)

Delay at 20^o

Mean delay (negative numbers indicate pelvic delay)

− 0.30 ± 0.88 s

−0.51 ± 0.90s

NS

β = − 0.21 (− 0.46, 0.44)

 Pelvic delay at 20^o of trunk flexion (10th centile, > 0.81 s

Number (%) of people with pelvic delay > 0.81 s

10 (10%)

29 (29%)

p = .0007

Prevalence ratio

2.9 (1.6–4.7)

 Lumbar delay at 20^o of trunk flexion (90th centile, > 0.15 s)

Number (%) of people with lumbar delay >.15 s

9 (9%)

18 (18%)

NS

Prevalence ratio

2 (0.9–3.8)

Mean movement duration

Time from start of flexion to full flexion

2.28 ± 0.94

3.18 ± 0.94

p < .0000

β = 0.90 (0.64, 1.16)

 Slow Trunk movement (10th centile, > 3.12 s)

Number (%) of people with Slow Trunk movement

10 (10%)

49 (47%)

p < .0000

Prevalence ratio

–

4.7 (2.9–6.5)

Mean pelvic tilt range

Range from full anterior tilt to full posterior tilt

29^o ± 13^o

29^o ± 13^o

NS

β = −0.3 (−3.8, 3.3)

 Small pelvic ROM (10th centile, < 11^o)

Number (%) of people with small pelvic tilt range

10 (10%)

10 (10%)

NS

Prevalence ratio

–

1.0 (0.4–2.2)

 Large pelvic ROM (90th centile, >49^o)

Number (%) of people with large pelvic flexion

10 (10%)

6 (6%)

NS

Prevalence ratio

–

0.6 (0.2–1.5)

Mean pelvic tilt ratio

Pelvic tilt range/range of trunk ROM change

2.1 ± 1.3

2.4 ± 1.4

NS

β = 0.4 (0, 0.7)

 Small tilt ratio (10th centile, < 0.69)

Number (%) of people with small pelvic tilt range

10 (10%)

6 (5.7%)

NS

Prevalence ratio

0.58 (0.2–1.5)

 Large tilt ratio (90th centile> 3.8)

Number (%) of people with large pelvic flexion

10 (10%)

13 (12%)

NS

Prevalence ratio

1.27 (0.6–2.6)

Mean relative sitting position

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

48 ± 35%

50 ± 35%

NS

β = 2 (−7, 12)

 Slumped sitting (10th centile, >  89%)

Number (%) of people with slumped sitting

10 (10%)

16 (16%)

NS

Prevalence ratio

–

1.7 (0.8–3.2)

 Upright sitting (90th centile, > 12%)

Number (%) of people with upright sitting

10 (10%)

10 (10%)

NS

Prevalence ratio

–

1.0 (0.4–2.2)