Gastrocnemius Medialis Architectural Properties at Rest and During Stretching in Female Athletes with Different Flexibility Training Background.

BACKGROUND: This study examined gastrocnemius medialis (GM) architectural properties and ankle joint range of motion (ROM) between female athletes with different flexibility training background.

METHODS: Elite rhythmic gymnasts ( n = 10) were compared to national level volleyball athletes ( n = 10). Fascicle length, pennation angle and muscle thickness at the medial and the distal part of GM, and ankle ROM were measured at rest and during 1 min of static stretching.

RESULTS: At rest, rhythmic gymnasts displayed longer fascicles compared to volleyball athletes, at the medial (5.93 ± 0.27 vs. 4.74 ± 0.33 mm, respectively, p = 0.001) and the distal part of GM (5.63 ± 0.52 vs. 4.57 ± 0.51 mm, respectively, p = 0.001), smaller pennation angle at the medial part (22.4 ± 2.5 vs. 25.8 ± 2.4°; respectively, p = 0.001) and greater ankle angle (121.7 ± 4.1 vs. 113.2 ± 3.7°, respectively, p = 0.001). During the 1 min of static stretching, gymnasts displayed greater fascicle elongation at the distal part ( p = 0.026), greater maximal ankle dorsiflexion ( p < 0.001) and muscle tendon junction displacement ( p < 0.001) with no difference between groups in pennation angles ( p > 0.145), muscle thickness ( p > 0.105), and fascicle elongation at mid-belly ( p = 0.063).

CONCLUSIONS: Longer muscle fascicles at rest and greater fascicle elongation at the distal part of GM may contribute to the greater ankle ROM observed in rhythmic gymnasts.