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

Area of Science:

• Neuroscience
• Biomechanics
• Rehabilitation Science

Background:

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

Purpose of the Study:

• To investigate differences in proactive balance control during walking between individuals post-stroke and those without stroke.
• To determine if stroke affects proactive strategies in response to predictable gait perturbations.

Main Methods:

• 14 individuals post-stroke and 14 controls walked on a treadmill with random and regular accelerations.
• Center of Mass (COM) speed changes quantified perturbation effects.
• Mechanical leg work measured proactive strategies to slow COM.

Main Results:

• Individuals without stroke better reduced peak COM speed during regular perturbations compared to those post-stroke (-0.016 m/s vs +0.004 m/s).
• The control group demonstrated greater reduction in positive leg work during perturbation steps (-5.7% vs +2.5%).

Conclusions:

• People post-stroke exhibit deficits in proactive balance control during predictable gait disturbances.
• These findings suggest an elevated susceptibility to falls in individuals post-stroke under such conditions.
• Future research should identify specific impairments underlying these proactive control deficits.