Toe joint mechanism of human (a), and of existing humanoid robots (b).

Robots That Look Like Human – Progressive Automations

PDF) Toe joint mechanism using parallel four-bar linkage enabling humanlike multiple support at toe pad and toe tip

Running-Robot

Human-Like Toe Joint Mechanism

PDF) Toe joint mechanism using parallel four-bar linkage enabling humanlike multiple support at toe pad and toe tip

PDF) Toe joint mechanism using parallel four-bar linkage enabling humanlike multiple support at toe pad and toe tip

Humanoid robot - Wikipedia

Robots and Their Killer Moves

Bipedal Humanoid Hardware Design: a Technology Review