Fatty infiltration (%)

Young age

Middle age

Old age

F

Overall P-value

L3/4

Multifidus

Right side

36.98 ± (14.16)

45.11 ± (13.753)

55.16 ± (17.957)

22.226

Over all P-value = 0.001*

Young VS Middle age = 0.004*

Young VS Old age = 0.001*

Middle VS Old age = 0.011*

Left side

36.4 ± (13.482)

46.14 ± (14.265)

55.49 ± (20)

22.885

Over all P-value = 0.001*

Young VS Middle age = 0.001*

Young VS Old age = 0.000

Middle VS Old age = 0.03

Erector spinae

Right side

38.23 ± (14.63)

45.43 ± (15.15)

52.5 ± (15.297)

14.044

Over all P-value = 0.001*

Young VS Middle age = 0.012*

Young VS Old age = 0.001*

Left side

37.42 ± (13.12)

44.71 ± (16.075)

53.25 ± (15.953)

17.061

Over all P-value = 0.001*

Young VS Middle age = 0.011*

Young VS Old age = 0.001*

L4/5

Multifidus

Right side

40.88 ± (13.71)

48.57 ± (13.273)

59.4 ± (18.026)

23.958

Over all P-value = 0.001*

Young VS Middle age = 0.006*

Young VS Old age = 0.001*

Middle VS Old age = 0.001*

Left side

39.98 ± (15.11)

47.71 ± (15.085)

58.25 ± (13.613)

23.478

Over all P-value = 0.002*

Young VS Middle age = 0.018*

Young VS Old age = 0.011*

Middle VS Old age = 0.017*

Erector spinae

Right side

45.33 ± (14.67)

53.8 ± (16.299)

59.16 ± (14.827)

13.18

Over all P-value = 0.001*

Young VS Middle age = 0.003*

Young VS Old age = 0.001*

Left side

44.16 ± (15.5)

53.29 ± (17.481)

60.37 ± (16.746)

15.123

Over all P-value = 0.001*

Young VS Middle age = 0.003*

Young VS Old age = 0.001*