Reliability of voluntary step execution behavior under single and dual task conditions.

Area of Science:

• Biomechanics
• Neuroscience
• Gerontology

Background:

• Assessing dynamic balance is crucial for fall prevention and mobility in aging populations.
• Ground reaction force (GRF) parameters during voluntary stepping offer insights into motor control.
• Investigating the reliability of these measures under varying cognitive loads is essential for clinical application.

Purpose of the Study:

• To determine the test-retest reliability of GRF parameters during voluntary step execution.
• To compare reliability between single-task (motor only) and dual-task (motor and cognitive) conditions.
• To identify the optimal number of trials for reliable GRF measurements in healthy and elderly adults.

Main Methods:

• Twenty-four healthy adults and 16 elderly adults performed a voluntary step execution task.
• Participants completed the task under single and dual-task conditions on three separate occasions.
• Ground reaction force data were analyzed for parameters including step initiation latency, preparation and swing phases, and foot-off/foot-contact times.

Main Results:

• Good to excellent test-retest reliability (Intraclass Correlation Coefficients) was observed for most GRF parameters.
• Reliability was consistent between single and dual-task conditions.
• Lower reliability was noted for swing phase duration, particularly in the elderly group.

Conclusions:

• Voluntary step execution, especially foot-off and foot-contact times, is a reliable measure for assessing dynamic balance.
• This test can be a valuable tool for diagnostic purposes and clinical intervention trials.
• The findings support the use of this test in both healthy and elderly populations under varying task demands.