Use of backward walking speed as an outcome measure in clinical populations: A systematic review.

Backward Walking Speed (BWS), is suggested to assess balance and mobility deficits and preliminarily shown to associate with fall risk. The purpose of this systematic review was to investigate whether psychometric measures have been clearly tested for BWS in clinical populations and whether uniform procedures have been used to measure BWS. Peer-reviewed articles indexed on PubMed, PEDro, and CINAHL published from 2000 to the present. The key words "backward walking" and "backward walking speed" were used. Studies that were included utilized BWS as an outcome measure in adults (>=18 years), objectively calculated BWS (as time taken or speed attained) and utilized BWS as an outcome measure. Studies were excluded if BWS was measured as part of a composite assessment, mechanistic studies aimed to understand the mechanisms of backward walking, and studies not written in English. A total of 42 studies were extracted that met the study eligibility criteria. Data quality for individual studies were assessed by two independent reviewers using the GRADE assessment tool. Only those studies that were at least moderate were included. 28 of the 42 studies met the eligibility and GRADE criteria and data were further extracted from these studies. The results of this systematic review revealed that BWS reliability has only been established in three clinical populations and validity in four clinical populations. Results also showed that majority of studies measure BWS at the self-selected speed (25/28) and on overground environments (27/28). However, instrumentation and distances used for BWS measurement greatly varied across studies. Distance used for BWS measurement ranged from 2.4 to 14m, with the most common distance being 5m. While mounting evidence highlights the potential of BWS as an outcome measure to assess balance and mobility in clinical populations, validation studies across different clinical populations is required. Importantly, there is an urgent need to validate a standardized protocol to measure BWS to minimize testing variations. There are no conflicts of interest related to this work. [ABSTRACT FROM AUTHOR]