‘Curved’ walking and a depth camera: New tool detects early cognitive decline
A new study suggests that to detect subtle gait impairments in older adults that often are prevalent in the early stages of cognitive decline, “throw them a curve.”
Gait analysis, examining the way an individual stands and walks, is emerging as a valuable, non-invasive complement to cognitive assessments that aid in early diagnosis and management. In clinical settings, gait and balance tests typically focus on a straight walking path.
This new study ventures into a different realm – curved path walking – a more natural yet complex activity. Straight walking is a rhythmic and simpler activity, whereas walking on a curving path requires greater cognitive and motor skills such as a transition time to change directions and correct balance.
College of Engineering and Computer Science researchers at Florida Atlantic University are some of the first to quantitatively compare the performance of healthy older adults versus older adults with mild cognitive impairment (MCI) in straight and curve walking. MCI is the early stage of cognitive decline and people with MCI have a much higher risk of transitioning to Alzheimer’s disease (AD).
For the study, researchers used a depth camera, which can detect and track 25 joints of body movement, to record study participants’ gait while performing the two different walking tests (straight versus curve). Signals from the 25 body joints were processed to extract 50 gait markers for each test, and these markers were compared between the two groups using descriptive statistical analyses.
Results, published in the Journal of Alzheimer’s Disease Reports, Volume 8, Issue 1, showed curve walking resulted in greater challenges for the MCI group and outperformed straight walking in detecting MCI. Furthermore, several gait markers showed significant differences between healthy controls and MCI patients.
Gait markers included two macro markers (average velocity and cadence), 24 micro temporal markers (duration of feet for various subphases of the gait cycle, such as stance, swing, step and stride phases), micro spatial markers (location changes of feet for various sub-phases of the gait cycle) and six micro spatiotemporal markers (velocity of feet for various sub-phases of the gait cycle). These markers provided detailed information on the functional performance of the participants during the gait tests.
Findings showed that 31 out of 50 gait markers (62 percent) were greater for the MCI group than healthy control older adults when the walking tests changed from straight walking to curve walking, and 13 markers showed significant differences between the two study groups.
Study findings did not show any significant differences in age and gender distribution between the two groups. However, the two groups had significant differences in body mass index (BMI), years of education and Geriatric Depression Scale (GDS) scores. Participants with MCI had a higher BMI, lower levels of education and higher GDS scores than the healthy older adults.
