The purpose of this study was to examine the changes in muscular activity between the left and right lower legs during gait in healthy children throughout temporal parameters of EMG and symmetry index (SI). A total of 17 healthy children (age: 8.06 ± 1.92 years) participated in this study. Five muscles on both legs were examined via the Vicon 8-camera motion analysis system synchronized with a Trigno EMG Wireless system and a Bertec force plate; onset-offset intervals were analyzed. The highest occurrence frequency of the primary activation modality was found in the stance phase. In the swing phase, onset-offset showed only a few meaningful signs of side asymmetry. The knee flexors demonstrated significant differences between the sides (p < 0.05) in terms of onset-offset intervals: biceps femoris in stance, single support, and pre-swing phases, with SI values = -6.45%, -14.29%, and -17.14%, respectively; semitendinosus in single support phase, with SI = -12.90%; lateral gastrocnemius in swing phase, with SI = -13.33%; and medial gastrocnemius in stance and single support phases, with SI = -13.33% and -23.53%, respectively. The study outcomes supply information about intra-subject variability, which is very important in follow-up examinations and comparison with other target groups of children.
Keywords: gait in children; gait symmetry; muscular activation; surface EMG.