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Table 1 Participant characteristics

From: Physical inactivity is associated with narrower lumbar intervertebral discs, high fat content of paraspinal muscles and low back pain and disability

 

Inactive

Moderately active

Active

P

(0 days)

(1 to 8 days)

(9 to 14 days)

N = 15

N = 38

N = 19

Age (years) *

47.2 (1.3)

45.1 (0.7)

46.5 (1.5)

0.29

Gender (n, % female) **

13 (86.7)

26 (68.4)

10 (52.6)

0.11

Weight (kg) *

99.0 (3.6)

96.5 (2.1)

84.4 (4.3)

0.02

Height (m) *

1.67 (0.01)

1.67 (0.01)

1.70 (0.02)

0.21

BMI (kgm −2 ) *

35.7 (1.3)

34.8 (0.8)

29.3 (1.5)

0.002

Intervertebral disc height (L1 to S1) (mm) *

    

Average

10.2 (4.1)

10.6 (2.6)

11.8 (3.6)

0.01

Paraspinal muscle properties

CSA (cm 2 ) *

    

Multifidus

6.9 (0.4)

6.9 (0.3)

7.2 (0.4)

0.76

Erector spinae

19.7 (1.1)

20.5 (0.7)

21.7 (1.0)

0.41

High fat content, n (%) **

    

Multifidus

9 (60.0)

13 (34.2)

3 (15.8)

0.03

Erector spinae

5 (33.3)

7 (18.4)

1 (5.3)

0.11

Chronic low back pain grade, n (%) ***

Pain free

3 (20.0)

6 (15.8)

5 (26.3)

0.049

Low disability, low intensity

5 (33.3)

24 (63.2)

14 (73.7)

Low disability, high intensity

4 (26.7)

1 (2.6)

0 (0.0)

High disability, moderately limiting

1 (6.7)

4 (10.5)

0 (0.0)

High disability, severely limiting

2 (13.3)

3 (7.9)

0 (0.0)

High pain/disability, n (%) ***

7 (46.7)

8 (21.1)

0 (0.0)

0.004

  1. Results displayed as mean (standard error of the mean) unless otherwise stated. * P values determined from pairwise comparison among the estimated marginal means; ** P values determined from chi-squared test; *** P values determined from Fisher’s exact test. BMI, body mass index; CSA, cross-sectional area.