Vasteaskele

Vasteaskele is a term used in biomechanics and neuromotor control to describe a rapid corrective step taken in response to a destabilizing perturbation in order to restore balance or continue forward movement. The action expands the base of support and shifts the body’s center of mass toward a stable position.

It is triggered by multimodal sensory input, including the vestibular system, proprioception, and vision, and can be reflexive or planned depending on task context. The step typically involves a brief stance pause followed by a quick swing of one leg and contact of the foot on the ground at a location that maximizes stability. Kinematic patterns vary: some steps are short and lateral, others longer and diagonal, and they are coordinated with reductions in velocity of the center of mass.

Vasteaskele is commonly studied in healthy young adults, older adults, and patient groups with impaired balance, such as after stroke or in peripheral neuropathy. It is used to quantify balance recovery strategies and to assess fall risk and rehabilitation progress.

In laboratory settings it is measured with motion capture and force plates, analyzing metrics such as onset latency, step length, swing duration, and margin of stability. Findings inform interventions to improve protective stepping and to design assistive devices and training programs.

In robotics and prosthetics, researchers implement protective-stepping models to enhance the balance performance of humanoid robots and powered orthoses, enabling safer interaction with real-world perturbations.