The Influence of Dynamic Balance on Ambulation Activity in People Post Stroke
Over one million adults in the US have functional limitations after stroke which limit their activity
and social participation at home and in the community. Limited ambulatory activity post-stroke
is often a major focus in rehabilitation and many rehabilitation researchers are studying the best
way to improve ambulation activity in this population. Studies of post-stroke locomotion have
been hampered by a few important factors. First, objective measurement of ambulatory activity
is problematic. Self-report measures of ambulatory activity are often unreliable and don’t reflect
the amount of walking actually performed by people with hemiparesis. Recent advances in
technology have given rise to step activity monitors that are becoming more widely used in
studies of ambulatory activity in the community. Step activity monitors are more reliable than
self-reported measures particularly in people who walk slowly or have significant gait
impairments. With a more reliable and valid measure of activity, rehabilitation researchers can
investigate the functional limitations that are most influential in ambulatory activity not only in the
clinical or laboratory setting but also in the community.
The second factor that has hampered studies of locomotion following stroke is the lack of
measures of dynamic balance that are valid and reliable. Investigations often include measures
of balance such as the Berg Balance Score (BBS) which involves postures and movements that
are more static than those used during locomotion or the Timed up and Go (TUG) test that
involves simple straight pathway ambulation. The BBS has been shown to have ceiling effect
in people post stroke, while the TUG is not able to distinguish between fallers and non-fallers.
Therefore, these outcome measures are not suitable to identify the balance deficits in
individuals post stroke across a wide range of stroke severity. Balance measures that are more
challenging and include postural transitions such as walking and turning, stepping over objects,
and walking at varying speeds would provide a better understanding of the effect of balance on
ambulatory activity than the tests commonly encountered in the locomotion literature. Two such
tests include the Functional Gait Assessment (FGA) and a modification of the Four Square Step
Test (mFSST) that are dynamic in nature, are challenging enough to be used on a wide range of
individuals, and should better predict ambulatory activity in people post-stroke. The purpose of
this study is to investigate the impact of dynamic balance on ambulatory activity in people post
stroke. We hypothesize that the FGA and the mFSST will be reliable and valid in people post
stroke and that each will account for an independent portion of the variation in ambulatory
activity. The findings of this research project will contribute to the tools that are available to
rehabilitation researchers who study locomotion and will provide a more thorough understanding
of influence of dynamic balance on ambulation activity in people post-stroke after they leave the
clinical setting.