Stroke impairs the proactive control of dynamic balance during predictable treadmill accelerations

Area of Science:

• Neuroscience
• Biomechanics
• Human Movement Science

Background:

• Gait balance relies on proactive and reactive control.
• Stroke often impairs reactive balance, but proactive control deficits remain unclear.
• Understanding proactive control deficits post-stroke is crucial for fall prevention strategies.

Purpose of the Study:

• To investigate differences in proactive balance control during walking between individuals with and without stroke.
• To assess the ability to utilize proactive strategies in response to predictable treadmill accelerations.

Main Methods:

• 14 adults with stroke and 14 controls walked on a treadmill with random and regular single-belt accelerations.
• Center of mass (COM) speed changes quantified perturbation effects.
• Mechanical leg work measured proactive adjustments to slow COM.

Main Results:

• Individuals without stroke demonstrated superior reduction in peak COM speed during regular interval accelerations compared to those with stroke (-0.023 m/s vs. -0.001 m/s).
• Participants without stroke exhibited greater reduction in positive leg work during perturbation steps (-7.7% vs. -1.9%).

Conclusions:

• Sensorimotor impairments from stroke significantly hinder the capacity for effective proactive adjustments during gait.
• These deficits in proactive control contribute to destabilizing effects and may increase fall risk in individuals post-stroke.