**3. Results**

#### *3.1. Gastrocnemius Medialis Architecture and Ankle Joint Angle at Rest*

Resting fascicle length of FT athletes was similar to FNT at the mid-belly (4.19 ± 0.37 vs. 4.24 ± 0.54 cm, respectively, t14 = −0.204, *p* = 0.841) and the distal part of gastrocnemius medialis (4.25 ± 0.35 vs. 4.18 ± 0.65 cm, respectively, t14 = 0.284, *p* = 0.780). FT and FNT athletes displayed also similar pennation angle and muscle thickness at the mid-belly (t14 = 0.661, *p* = 0.519 and t14 = 0.002, *p* = 0.998, respectively) and the distal part of the gastrocnemius medialis (t14 = −1.297, *p* = 0.216 and t14 = 0.807, *p* = 0.433, respectively) (Table 2). Resting ankle angle was larger in FT by 8% compared with FNT (120.86 ± 4.19◦ vs. 110.95 ± 5.79◦, respectively, t14 = 3.982, *p* = 0.001) (Table 2).

**Table 2.** Changes in muscle architecture characteristics and ankle angle following stretching for the flexibility trained (FT) (n = 10) and not trained athletes (FNT) (n = 6).


†: *p* < 0.001 from the corresponding value in flexibility trained athletes.

#### *3.2. Gastrocnemius Medialis Architecture and Ankle Joint Angle during Ankle Dorsiflexion Stretching*

During stretching, the elongation of fascicles was greater in FT athletes compared to the FNT at the mid-belly of the muscle by 23% (+1.67 ± 0.37 cm vs. +1.28 ± 0.22 cm, *p* = 0.048) and the distal part by 47% (+1.84 ± 0.67 vs. +0.97 ± 0.29 cm, *p* = 0.013). Furthermore, FT athletes displayed greater maximal ankle dorsiflexion by 13% (*p* < 0.001), as well as greater muscle tendon junction displacement by 33% (*p* < 0.001) (Table 2). No differences were found between groups in muscle thickness at mid-belly and at the distal part (*p* > 0.053). However, FNT athletes displayed greater pennation angle at the mid-belly of gastrocnemius medialis (−2.90 ± 1.29 vs. −4.93 ± 1.91 vs., *p* = 0.048), but not at the distal part (*p* = 0.362) (Table 2).

#### *3.3. Correlations Between Fascicle Length, Ankle Angles and MTJ Displacement*

When all athletes were considered as a group, significant correlations were found between fascicle elongation at the distal part of GM and MTJ displacement (*r* = 0.752, *p* < 0.01) and ankle angle during stretching (*r* <sup>=</sup>−0.638, *p* < 0.01). Moreover, a significant correlation was found between MTJ displacement and ankle angle during stretching (*r* = −0.610, *p* < 0.05).
