Dynamic stability in elders: momentum control in locomotor ADL

Area of Science:

• Biomechanics
• Gerontology
• Neurology

Background:

• Locomotion requires momentum control, crucial for activities like sit-to-stand and gait.
• The interplay between momentum control and balance in older adults, especially those with balance impairments, remains understudied.
• While slower gait in elders is known, the underlying mechanical mechanisms are not well understood.

Purpose of the Study:

• To quantify whole-body and upper-body linear and angular momentum in healthy elders during sit-to-stand and gait.
• To compare momentum characteristics between healthy elders and those with bilateral vestibular hypofunction (BVH).

Main Methods:

• Matched cohort study comparing 10 elders with BVH to 10 healthy elders (aged 67-90).
• Calculation of linear and angular momentum during sit-to-stand and free/paced gait.
• Statistical comparison using means and 95% confidence intervals.

Main Results:

• Elders with BVH demonstrated significantly lower linear and angular momentum during sit-to-stand compared to healthy elders.
• Despite slower walking speeds, BVH elders exhibited excessive lateral momentum during gait.
• Healthy elders reduced momentum generation, likely as a compensatory strategy for balance control.

Conclusions:

• Healthy elders may decrease gait velocity to manage momentum due to strength or balance limitations.
• Elders with BVH further reduce momentum to minimize fall risk but struggle with lateral momentum control during gait.
• Impaired lateral momentum control in BVH elders contributes to balance loss and falls, common in this population.