Dynamic balance during walking adaptability tasks in individuals post-stroke.

Area of Science:

• Neuroscience
• Biomechanics
• Rehabilitation Science

Background:

• Community ambulation is challenging post-stroke, requiring both steady-state walking and adaptability.
• Previous research on post-stroke balance control primarily focused on steady-state walking, neglecting adaptability tasks.

Purpose of the Study:

• To quantify and compare dynamic balance demands during walking adaptability tasks in individuals post-stroke versus healthy adults.
• To identify underlying mechanisms contributing to dynamic balance differences post-stroke.

Main Methods:

• Collected kinematic data from 15 individuals with post-stroke hemiparesis and 10 healthy adults.
• Assessed dynamic balance using whole-body angular momentum during single-leg stance in various walking tasks (forward/backward walking, obstacle negotiation, step-up).
• Examined foot placement and plantarflexor muscle activation as key balance mechanisms.

Main Results:

• Individuals post-stroke exhibited significant frontal plane dynamic balance deficits, particularly during the paretic single-leg stance.
• These deficits correlated with wider paretic foot placement, elevated body center-of-mass, and reduced soleus muscle activity.
• Obstacle negotiation presented the highest balance challenge, especially during the trailing leg single-stance phase.

Conclusions:

• Dynamic balance impairments in the frontal plane are a key challenge for post-stroke community ambulation.
• Wider foot placement and reduced plantarflexor activation contribute to these balance deficits.
• Targeting paretic foot placement and ankle plantarflexor activity during obstacle negotiation may improve dynamic balance and walking ability post-stroke.