Neuromuscular Strategies in Dominant and Non-Dominant Legs in Dancers During Dynamic Balance Tasks.

Introduction

Ballet-based dance training emphasizes the equal development of both legs. However, dancers often perceive differences between their legs during balance or landing. There still needs to be more consensus on the functional difference between dominant (D) and non-dominant legs (ND). Therefore, this study investigated both legs' neuromuscular strategy in single-leg balance and landing based on leg dominance.

Methods

Thirteen female dancers (age: 22.2 ± 2.8 years) with no history of ankle injuries in the past year participated in the study. Based on the questionnaire, the dominant leg was set, which legs were preferred to balance, generate strength, and land. Joint kinematics and ground reaction force (GRF) were analyzed using a three-dimensional motion analysis system and force plates during single-leg balance (SLB), passé balance (PB), sissone simple (SS), and sissone ouverte (SO). The tibialis anterior (TA), medial gastrocnemius (MG), peroneus longus (PL), and gluteus medius (GM) activation were measured by wireless surface electromyography (EMG). Displacement (cm) of the center of pressure and the dynamic postural stability index (DPSI), a balanced score post dynamic tasks, were calculated.

Results

Bilateral leg balance ability was observed based on joint kinematics and DPSI during SLB, PB, SS, and SO. Higher TA activity was noted during PB in ND legs than in D legs (P = .038). PL activation was significantly increased in ND legs (69.3 ± 34.4%) than in D legs (45.6 ± 19.2%) before contact during SS and SO (P < .05). After landing with ND legs, dancers regulated postural stability with increasing TA activation (P < .05).

Conclusions

Pre-activation of PL before landing with ND legs increases ankle stiffness, enhancing stability. Conversely, D legs achieve balance with lower activation levels. The findings highlight significant differences between legs in dancers, suggesting that leg dominance should be considered in future training and performance strategies.