Table 2 Univariable analysis of the histogram features of the lower leg muscles

10th Percentile

22.4 ± 5.3

24.2 ± 5

19.0 ± 4

< 0.001^*

90th Percentile

63 (60, 65)

64 (63, 65)

61 (57, 64)

0.006^*

CV

37.2 (34.4, 41.8)

35.6 (32.8, 38.2)

41.0 (38.9, 45.9)

< 0.001^*

Energy (10⁸)

6.3 ± 2.7

6.8 ± 2.7

5.2 ± 2.4

0.04^*

Entropy

1.6 ± 0.1

1.5 ± 0.1

1.6 ± 0.1

0.32

IQR

20 (19, 21)

20 (19, 21)

21 (20, 22)

0.009^*

Kurtosis

3.8 (3.5, 4.2)

3.8 (3.5, 4.3)

3.6 (3.5, 3.9)

0.20

Maximum

156.6 ± 14.2

157.6 ± 14.3

154.8 ± 13.8

0.50

Mean

44.0 (39.2, 45.8)

44.6 (43.0, 47.0)

39.5 (37.0, 43.5)

< 0.001^*

MAD

12.6 ± 0.9

12.4 ± 0.9

12.9 ± 0.7

0.04^*

Median

44 (39, 46)

45 (43, 47)

39 (36, 44)

< 0.001^*

Minimum

-61.4 ± 16.6

-64.4 ± 16.7

-56.1 ± 15

0.08

Mode

45 (39, 47)

47 (44, 48)

40 (34, 44)

0.001^*

Range

218.0 ± 24.1

221.9 ± 23.2

210.9 ± 24.2

0.11

RMAD

8.6 ± 0.7

8.5 ± 0.7

8.9 ± 0.6

0.01^*

RMS

45.8 ± 4.5

47.2 ± 4

43.1 ± 4

< 0.001^*

Skewness

0.1 (0.0, 0.4)

0.0 (0.0, 0.2)

0.3 (0.1, 0.6)

0.002^*

SD

16.1 (15.7, 16.9)

16.0 (15.5, 16.4)

16.7 (16.0, 17.1)

0.03^*

Uniformity

0.4 (0.4, 0.4)

0.4 (0.4, 0.4)

0.4 (0.4, 0.4)

0.26

Variance

260 (247, 286)

256 (241, 270)

280 (255, 294)

0.03^*