Exploring phase dependent functional gait variability.

Area of Science:

• Biomechanics
• Neuroscience
• Gerontology

Background:

• Gait variability is crucial for assessing sensorimotor function in older adults, with fallers often showing altered patterns.
• While often seen as error, gait variability also reflects adaptive responses to perturbations, termed functional variability, ensuring motor control stability.

Purpose of the Study:

• To investigate phase-dependent functional gait variability across different body segments (foot, shank, thigh) during normal walking in older adults.
• To analyze how variability changes throughout the gait cycle and its relation to specific kinematic events.

Main Methods:

• Utilized inertial sensors (MTw2, Xsens) to record foot, shank, and thigh kinematics in 25 older participants (70±6 years).
• Defined phase-dependent variability using the standard deviation of the Euclidean norm of angular velocity data.
• Employed statistical parametric mapping to compare variability across body segments and identify significant differences during the gait cycle.

Main Results:

• Foot kinematics exhibited higher variability during parts of the swing phase compared to shank and thigh segments.
• Shank kinematics showed less variability than thigh kinematics at specific points (62-64%) within the swing phase.
• Variability magnitudes were smallest during mid-swing, coinciding with the point of minimum toe clearance.

Conclusions:

• Evidence suggests phase-dependent functional variability is prominent in the swing phase of gait.
• Reduced variability in foot kinematics during mid-swing, where minimum toe clearance occurs, indicates a controlled, stable movement pattern during this critical phase.