Table 2.

DTI indices using whole muscle histogram analysis of the medial gastrocnemius (MG) and lateral gastrocnemius (LG) muscles for young (Y) and senior (S) subjects.

		Medial gastrocnemius			Lateral gastrocnemius
		Young(Y)	Senior (S)	%2	Young(Y)	Senior (S)	%
FA1	Mean	0.2527 ± 0.0785	0.2813 ± 0.1004	11.3	0.2378 ± 0.0617	0.2419 ± 0.0707	1.7
	Kurtosis	4.69	2.98	−36.4	6.67	4.01	−39.9
	Skewness	0.5	0.28	−43.2	0.79	0.08	−89.9
λ 1 3	Mean	0.0018 ± 0.0004	0.0022 ± 0.0005	20.1*	0.0018 ± 0.0003	0.0021 ± 0.0003	13.7*
	Kurtosis	10.07	6.54	−35.1	14.42	14.36	−0.4
	Skewness	1.22	1.58	29.2	1.62	2.13	32
λ 2 3	Mean	0.0013 ± 0.0003	0.0015 ± 0.0003	16.0*	0.0014 ± 0.0002	0.0015 ± 0.0003	11.8
	Kurtosis	9.74	6.56	−32.7	15.71	12.42	−20.9
	Skewness	1.22	1.56	27.8	1.77	2.03	14.4
λ 3 3	Mean	0.0011 ± 0.0002	0.0012 ± 0.0003	13.9*	0.0012 ± 0.0002	0.0013 ± 0.0003	13.8*
	Kurtosis	10.49	6.39	−39.1	12.96	12.37	−4.5
	Skewness	0.92	1.32	43.9	1.32	1.94	47.8

¹FA: fractional anisotropy, unitless (range: 0-1)

²% is change calculated with respect to the young group

³Eigenvalues λ₁, λ₂, λ₃ are in units of mm²/sec.

^*significant at p<0.05; two-tailed t-test for independent samples (young-senior age groups)