Muscle synergies as functional low-dimensional building blocks of the neuromotor system regulate the activation patterns of muscle groups in a modular structure during locomotion. The purpose of the current study was to explore how older adults organize locomotor muscle synergies to counteract unpredictable and predictable gait perturbations during the perturbed and the recovery steps. Sixty-three healthy older adults (71.2 ± 5.2 years) participated in the study. Mediolateral and …