Gymnasts and non-athletes muscle activation and torque production at the ankle joint

摘要

Artistic Gymnasts (AG) execute specific movements that require substantial movement control and force production at the ankle joint. This high demand might change the neuromechanical properties of the ankle joint muscles in these athletes compared to non-athlete girls (NAG). The aim of this study was to compare muscle activation and torque production at the ankle joint between AG and NAG. Ten AG (11.70 ± 1.06 years of age) and 10 NAG (11.70 ± 1.49 years of age) participated in the study. Electromyographic (EMG) signals of medial gastrocnemius (MG), soleus (SO) and tibialis anterior (TA) were obtained simultaneously to the maximal isometric plantarflexion (PFT) and dorsiflexion (DFT) torques of the dominant limb during a maximal voluntary isometric contraction (MVIC) at five different joint angles (20°, 10°, 0°, -10° e -20°). Neuromuscular efficiency was also calculated by the Torque/EMG ratio. AG presented higher PFT (p0.01) and smaller DFT (p0.05) at all joint angles compared to NAG. RMS values from the three muscles were similar between groups (p0.05). In addition, AG showed higher values for plantarflexion neuromuscular efficiency and smaller values of dorsiflexion neuromuscular efficiency compared to the NAG (p0.01). Higher sports demands of AG determined higher PFT, higher plantarflexor efficiency, smaller DFT but similar activation of MG, SO and TA compared to NAG.