Figure 4.

Muscles synergies extracted from each experimental condition. (A) Muscle synergies extracted from perturbation responses during standing, slow walking, and self-selected walking. All but one of the muscle synergies used in slow walking perturbation responses was similar to those used in standing balance postural responses. All but one of the muscle synergies used in self-selected walking perturbation responses was similar to those used in standing and/or slow walking postural responses. Correlations between each muscle synergy vector and the corresponding muscle synergy from standing balance are shown. (B) Muscle synergies extracted from unperturbed walking. Muscle synergies extracted from standing balance perturbation responses were similar to those extracted from the entire timecourse of many trials of unperturbed walking. In this subject, one additional muscle synergy was identified from unperturbed walking that was not identified in standing postural responses.