Components of gait in people with and without mild cognitive impairment

Background: Several objective gait parameters are associated with cognitive impairment, but there is limitedknowledge of gait models in people with mild cognitive impairment (MCI).Research question: How can 18 objective gait characteristics be used to define different components of gait inpeople with MCI (with suspected incipient neurocognitive disorder) and cognitively unimpaired people (CU),respectively?Methods: Spatiotemporal gait data were collected by using an electronic walkway (GAITRite®), i.e. assessmentsin comfortable gait speed. Using cross-sectional gait data, two principal component analyses (PCA) were performed(varimax rotation) to define different components of gait in people with MCI (n = 114) and CU (n = 219),respectively, from the BioFINDER-2 study.Results: Both PCAs produced four components, here called Variability, Pace/Stability, Rhythm and Asymmetry.Total variance explained was 81.0% (MCI) versus 80.3% (CU). The Variability component explained the largestamount of variance (about 25%) in both groups. The highest loading gait parameter was the same for bothgroups in three out of four components, i.e. step velocity variability (Variability), mean step length (Pace/Stability)and mean step time (Rhythm). In the asymmetry component, stance time asymmetry (MCI) and swingtime asymmetry (CU) loaded the highest.Significance: The gait components seem similar in people with and without MCI, although there were somedifferences. This study may aid the identification of gait variables that represent different components of gait.Gait parameters such as step velocity variability, mean step length, mean step time as well as swing and stancetime asymmetry could serve as interesting core variables of different gait components in future research in peoplewith MCI (with suspected incipient neurocognitive disorder) and CU. However, the selection of gait variablesdepends on the purpose. It needs to be noted that assessment of variability measures requires more advancedtechnology than is usually used in the clinic