Corrigendum: Lateral Symmetry of Synergies in Lower Limb Muscles of Acute Post-stroke Patients After Robotic Intervention - Tan, Chun Kwang; Kadone, Hideki; Watanabe, Hiroki; Marushima, Aiki; Yamazaki, Masashi; Sankai, Yoshiyuki; Suzuki, Kenji (Frontiers in Neuroscience, 2020)