Walkway Length Determination for Steady State Walking in Young and Older Adults

Gait analysis is an integral part of functional assessment in older adults and a routine clinical tool to treat patients of all ages who have pathology or disease related to sensory or motor function. Gait analyses have been used to determine “normal” walking for different age groups (Blanke & Hagemen, 1989; Bohannon, Andrews, & Thomas, 1996; Hageman & Blanke, 1986; Larish, Martin, & Mungiole, 1988; Murray, Kory, & Clarkson, 1969), to document current status of a patient’s gait (Maki, 1997; Zahedi, Spence, Solomonidis, & Paul, 1987), and to assess changes over time related to aging, pathology, or treatment (Hausdorff, Rios, & Edelberg, 2001; Jylhä, Guralnik, Balfour, & Fried, 2001; Macfarlane & Visser, 2003; MacRae, Feltner, & Reinsch, 1994; Whittle, 1996). Regardless of whether gait evaluation is merely recording speed with a stopwatch, performing a qualitative observation, or a detailed three-dimensional kinetic/kinematic assessment, a basic requirement of all of these applications relates to reliability of the data and whether the evaluated gait represents the participant’s typical gait pattern under the set conditions. A challenge facing researchers or clinicians is to identify and record a representative gait pattern excluding acceleration and deceleration variations, which are almost impossible to detect in normal walkers (Zahedi et al., 1987). The walkway space is often limited which requires minimizing the distance for acceleration and deceleration so that the portion of the walkway where the representative gait is used can be maximized. In several review articles on how to conduct clinical gait analyses, there was no guidance for identifying a representative gait, the variability associated with changing walking speed, or how many steps or distance participants needed to accelerate to steady state (SS) and then decelerate (Baumann, 1991; Coutts, 1999; Harris & Wertsch, 1994; Laughman, Askew, Bleimeyer, & Chao, 1984; Rosendal, 1991; Whittle, 1996). Preferred walking speed and fast speed are commonly used in gait analyses. People tend to select a preferred walking speed that is most efficient (ml O2/m) in energy cost (Fisher & Gullickson, 1978), and gait mechanics for SS preferred walking speed show less variability than at either a fast or slow pace. Self-selected speed has been shown to be reliable and reproducible with no significant differences between tests (Rechnitzer, Cunningham, & Howard, 1989). In older adults, maximum speed walking identifies functional impairments more effectively than preferred speed walking (Bohannon et al., 1996) with gait speed providing an index of functional status (Jylhä et al., 2001). Gait measures to identify functional ability and/or performance may include the time needed to perform a task, like walking a set distance which includes both acceleration (AC) and deceleration (DC) distances and, thus, represents an average speed, not a SS speed. A risk of disability in community-dwelling populations was assessed by the time to walk either 8 feet or 3 m from a standing start (Guralnik et al., 2000), and Nelson et al. (2004) used the best of three measurements over a Walkway Length Determination for Steady State Walking in Young and Older Adults