Background: Manufacturers have introduced specific shoes featuring unstable sole constructions to induce neuromuscular training stimuli. Previous experiments focused primarily on analysing effects of unstable shoe constructions in comparison to ‘regular’ shoes or to barefoot walking. The aim of this study was to compare muscle activity during walking when using three different unstable shoe constructions.Methods: Twelve healthy male subjects participated in this study. Muscle activities of the lower leg were analysed during treadmill walking by surface electromyography (EMG). First, each subject performed an unshod trial (BF = barefoot – control condition). Then, MBT® shoe (MBT), Finnamic-Schuh® (FIN), and Reflex Control® shoe (RC) were randomly applied and tested. EMG-activities of m. tibialis anterior, m. gastrocnemius lateralis, and m. peroneus longus were recorded. In all muscles we calculated integrated EMG (iEMG) for each ground contact phase.Results: When wearing RC the muscle activity of the m. gastrocnemius lateralis and the summarised muscle activity of the lower leg increased significantly when compared to FIN and BF (p = 0.001 to 0.013). There were no significant differences between RC and MBT (p = 0.207 to 0.212). Concerning iEMG of m. peroneus longus and m. tibialis anterior there were no statistically relevant differences detected between testing situations (p = 0.205 to 1.000).Conclusion: The results of the present study indicate that different unstable shoe constructions induce varying demands to the neuromuscular system while walking on a treadmill. We expect the demands of unstable shoe constructions (MBT and especially RC) to be beneficial as sensorimotor training stimuli during walking.