Gait Analysis Using Accelerometry Data from a Single Smartphone: Agreement and Consistency between a Smartphone Application and Gold-Standard Gait Analysis System.

Spatio-temporal parameters of human gait, currently measured using different methods, provide valuable information on health. Inertial Measurement Units (IMUs) are one such method of gait analysis, with smartphone IMUs serving as a good substitute for current gold-standard techniques. Here we investigate the concurrent validity of a smartphone placed in a front-facing pocket to perform gait analysis. Sixty community-dwelling healthy adults equipped with a smartphone and an application for gait analysis completed a 2-min walk on a marked path. Concurrent validity was assessed against an APDM mobility lab (APDM Inc.; Portland, OR, USA). Bland-Altman plots and intraclass correlation coefficients (agreement and consistency) for gait speed, cadence, and step length indicate good to excellent agreement (ICC2,1 > 0.8). For right leg stance and swing % of gait cycle and double support % of gait cycle, results were moderate (0.52 < ICC2,1 < 0.62). For left leg stance and swing % of gait cycle left results show poor agreement (ICC2,1 < 0.5). Consistency of results was good to excellent for all tested parameters (ICC3,1 > 0.8). Thus we have a valid and reliable instrument for measuring healthy adults' spatio-temporal gait parameters in a controlled walking environment.

The association between objective measurements of sleep quality and postural control in adults: A systematic review.

We systematically reviewed the association between objective sleep quality and postural control based on objective measurements. We searched the electronic databases PUBMED, CINAHL, SCOPUS and Web of Science for studies assessing the relationship between objective measurements of sleep and postural control or gait performance among adults above age 18. All types of articles until April 2020 were considered. The search yielded 2967 articles, and out of these, inclusion criteria were met by five cross-sectional and two longitudinal studies (N = 7). Three studies found a positive correlation between sleep efficiency and gait speed, three studies found a negative correlation between wake time after sleep onset (WASO) and gait speed or postural control, and one study found no association between sleep parameters and gait speed. Objectively measured sleep quality parameters such as sleep efficiency and WASO were associated with objective measures of posture and gait. More studies with longitudinal designs are needed to expose causal pathways and mechanisms underlying these relationships.