Emotional states influence postural control, but previous studies have primarily focused on postural dynamics during quiet standing while viewing emotional pictures, using the center of pressure as a measure. However, the effects of emotions on neuromuscular activities related to postural control remain unclear. During quiet standing, neuromuscular activities of ankle plantarflexors are crucial for maintaining postural balance, both in terms of and synchronized muscle activity. This study aimed to clarify the emotional effects on the individual and synchronized neuromuscular activities of ankle plantarflexors during quiet standing. Twenty-four healthy male participants were instructed to view emotional pictures for 72 seconds while standing. The task was repeated four times with four picture conditions, which composed of two arousals (High and Low) and two valences (Pleasant and Unpleasant). During the task, electromyograms (EMG) of the tibialis anterior (TA), soleus (SOL), and medial (MG) and lateral gastrocnemius muscles (LG) were recorded. The EMG signals were rectified, and mean amplitude was calculated to assess individual neuromuscular activity. Inter-muscular coherence (IMC) between ankle plantarflexors was calculated to assess synchronized neuromuscular activity, with mean IMC calculated at 0–4 Hz and 8–12 Hz. Results showed that aroused emotions induced a reduction in SOL neuromuscular activity, leading to partial backward body leaning. Furthermore, synchronized neuromuscular activities at 8–12 Hz in the SOL-MG and MG-LG pairs were increased under aroused emotional states, indicating enhanced physiological tremor and a reduced capacity for postural adjustment. These findings deepen our understanding of the emotional impacts on standing postural control.