Short communicationValidation of gait event detection by centre of pressure during target stepping in healthy and paretic gait
Introduction
Force instrumented treadmills facilitate online kinetic measurement of a high volume of steps in a small space with the safety of support harnesses (Merholz and Elsner, 2014) and, combined with visual projection, can allow practice of altering walking in response to cues (e.g. stepping to targets, over or around obstacles (Heeren et al., 2013). For these reasons use of instrumented treadmills for rehabilitation and clinical assessment is increasing (Bank et al., 2011, Duysens et al., 2012, Heeren et al., 2013, Hollands et al., 2014, Hollands et al., 2013, Mazaheri et al., 2015, Mazaheri et al., 2014, Peper et al., 2015, Timmermans et al., 2016, van Ooijen et al., 2015, Weerdesteyn et al., 2006).
Single uniaxial force instrumentation of the treadmill belt affords centre of pressure (CoP) gait event detection (GED) as a proxy for gold standard kinetic (dual, multi-axial, force-plates) or kinematic GED. CoP GED has been shown to correspond well with kinematic GED during steady-state treadmill walking in young healthy adults (Roerdink et al., 2008). However, it is not known whether CoP GED corresponds with kinematic GED when steps are altered in response to environmental cues, or when alterations in CoP trajectories occur due to pathology (i.e. stroke (Wong et al 2004)).
To support valid gait assessment in the context of growing treadmill use in clinical assessment, this study aimed to determine if there are differences in CoP and kinematic GED in young healthy (YH) and stroke survivors (SS) during treadmill walking. We compare GED methods in the walking condition of varying steps; the context in which they are increasingly being applied. Specific questions are:
- (1)
Are there significant differences between methods within groups?
- (2)
Are differences between methods greater in SS than YH (and according to paretic and non-paretic limbs)?
Section snippets
Participants
YH, aged 18–35 years, were recruited by poster advertisement across the University. SS were recruited from community stroke support and exercise groups in Greater Manchester. Participants were included if they could walk ten-metres within 30 s, had no visual impairments preventing sight of stepping targets, and no co-morbidities affecting walking.
The University of Salford, College of Health and Social Care Research Ethics Committee approved the study, and all participants provided written
Results
A total of 7 YH and 13 SS participated (demographics see Table 1). No abnormalities in cyclograms which would have prevented CoP GEDs were found on visual inspection of individual participant data (Fig. 2).
Discussion
Traditionally, GED is applied during steady state walking on a treadmill/over-ground (Roerdink et al., 2008, Roerdink et al., 2007). However, owing to the importance of adapting steps in response to environmental cues and the increasing use of instrumented treadmills to train and assess gait in this context, we robustly compared the performance of GED methods during step alterations (longer, shorter, and narrowing) for both YH and SS.
We found that, for SS, detecting FC using VFC and FO using
Conclusion
This study showed that CoP based GED agreed within 100 ms with kinematic algorithms suggested for use with SS walking on a treadmill. The differences in GED methods reflect the differences between movement (kinematics) vs weight transfer (kinetics) and suggest CoP GED may be more appropriate for gait analyses of SS than kinematic methods; even when walking and varying steps.
Conflict of interest statement
We confirm that there is no conflict of interest with the current submission and a full review and understanding of copyright guidelines has been completed.
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2020, Gait and PostureCitation Excerpt :One stroke survivor showed signs of egocentric and allocentric neglect, but was able to see and step to targets projected on the treadmill and participate safely. A treadmill with a single embedded force platform (C-Mill, MotekForcelink, Culemborg, The Netherlands) was used allowing for online gait event detection while projecting visual stepping targets, as previously validated [18]. Two forearm crutches were installed at the side of the treadmill adjacent to handlebars for the supported trials (see Fig. 1A).
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2023, Research Square
- 1
Stroke and Vascular Centre, Faculty of Medical and Human Sciences, University of Manchester, Clinical Sciences Building, Room 235, Salford Royal NHS Foundation Trust, Stott Lane, Salford, M6 8HD
- 2
Salford University, School of Health Science, Allerton Building, Friedrick road, Salford, United Kingdom, M6 6PU.