Inter-limb asymmetry characteristics and their impact on bilateral jump performance in elite gymnasts: a comparison across varying mechanical loads

This study investigated task-specific biomechanical regulation and the impact of inter-limb asymmetry on athletic performance in fourteen elite gymnasts. Participants (sex: 7 males, 7 females; age: 20.14 ± 1.23 years) performed bilateral and unilateral drop jump (DJ) and hopping tasks while kinetic data were collected via force plates to calculate vertical stiffness (Kvert), center of mass (COM) displacement, vertical ground reaction force (vGRF), and inter-limb asymmetry. Compared with hopping, the drop jump task exhibited lower Kvert and vGRF but greater COM displacement (all p < 0.001). COM asymmetry was significantly greater during DJ than during hopping ( p < 0.05) and was positively associated only with bilateral hopping reactive strength index (RSI) in the pooled sample ( p < 0.05). In contrast, vGRF asymmetry during hopping was negatively associated with RSI in both bilateral hopping and bilateral DJ tasks ( p < 0.05). These correlation analyses were exploratory and were not adjusted for multiple comparisons. These findings suggest that different forms of asymmetry may carry distinct functional implications under varying mechanical loading conditions. Furthermore, the self-selected frequency hopping task may represent a candidate approach for assessing inter-limb functional balance in elite gymnasts.