Changes in step-width during dual-task walking predicts falls

Area of Science:

• Gerontology
• Biomechanics
• Neuroscience

Background:

• Falls are a significant concern for older adults, impacting independence and quality of life.
• Gait pattern alterations under dual-task conditions may reflect underlying neurological or biomechanical changes associated with fall risk.

Purpose of the Study:

• To investigate the association between gait pattern changes during dual-tasking and the risk of falling in community-dwelling older adults.
• To determine if dual-task cost (DTC) in gait characteristics can serve as a prognostic indicator for falls.

Main Methods:

• 230 physically independent older adults (≥75 years) underwent gait analysis using an electronic walkway under single- and five dual-task conditions.
• Dual-task cost (DTC) was calculated by comparing gait parameters (e.g., step-width, step-time, step-length variability) between single- and dual-task walking.
• Participants were prospectively followed for one year to record fall occurrences.

Main Results:

• Nearly half (48%) of participants experienced at least one fall during the follow-up period.
• Increased fall risk was associated with changes in mean step-width during a subtraction dual-task.
• Decreased fall risk was linked to changes in mean step-width, mean step-time, and step-length variability during a cup-and-saucer carrying dual-task.
• Prognostic values for mean step-width DTC included a negative likelihood ratio of 0.5 and a positive likelihood ratio of 2.3.

Conclusions:

• Gait pattern modifications, specifically in step-width, step-time, and step-length variability, during dual-tasking are associated with future fall risk in older adults.
• The nature of the secondary task influences whether dual-task cost indicates an increased fall risk or a compensatory protective strategy.