Table 1 Demographic data and muscle properties in the two age groups

Demographic data

 Age (years)

23.33 (3.75)

67.92 (2.11)

 Gender (male/female)

5/7

6/6

 Length (m)

1.76 (0.11)

1.70 (0.05)

 Mass (kg)

70.83 (11.46)

70.08 (13.47)

Muscle architecture and echo intensity data

 Gastrocnemius medialis

  PA rest (°)

18.71 (3.12)

16.16 (2.91)

  PA contraction (°)

21.77 (3.45)

19.07 (5.17)

  FL rest (cm)

5.12 (0.75)

6.53 (2.91)

  FL contraction (cm)

4.51 (1.03)

5.34 (1.89)

  MT rest (cm)

1.63 (0.28)

1.61 (0.29)

  MT contraction (cm)

1.72 (0.42)

1.64 (0.30)

 Tibialis anterior

  PA rest (°)

9.82 (2.23)

11.81 (2.51)

  PA contraction (°)

13.10 (3.55)

14.88 (3.28)

  FL rest (cm)

6.26 (0.83)

6.51 (1.14)

  FL contraction (cm)

5.44 (0.90)

5.66 (0.91)

  MT rest (cm)

1.04 (0.21)

1.16 (0.17)

  MT contraction (cm)

1.17 (0.27)

1.28 (0.18)

 Vastus lateralis

  PA rest (°)

13.30 (1.92)

10.60 (2.79)

  PA contraction (°)

12.72 (3.30)

9.87 (2.52)

  FL rest (cm)

12.14 (2.12)

10.96 (3.81)

  FL contraction (cm)

11.18 (2.53)

11.90 (3.75)

  MT rest (cm)

2.71 (0.40)

1.98 (0.34)

  MT contraction (cm)

2.57 (0.34)

2.09 (0.23)

MVF data (N)

 Gastrocnemius medialis

538.18 (259.73)

421.33 (153.97)

  Tibialis anterior

163.83 (66.59)

170.17 (54.98)

  Vastus lateralis

441.55 (152.80)

309.83 (102.03)