Reliability of spatiotemporal and kinetic gait parameters determined by a new instrumented treadmill system

Abstract

BackgroundDespite the emerging use of treadmills integrated with pressure platforms as outcome tools in both clinical and research settings, published evidence regarding the measurement properties of these new systems is limited. This study evaluated the within– and between–day repeatability of spatial, temporal and vertical ground reaction force parameters measured by a treadmill system instrumented with a capacitance–based pressure platform.MethodsThirty three healthy adults (mean age, 21.5 ± 2.8 years; height, 168.4 ± 9.9 cm; and mass, 67.8 ± 18.6 kg), walked barefoot on a treadmill system (FDM–THM–S, Zebris Medical GmbH) on three separate occasions. For each testing session, participants set their preferred pace but were blinded to treadmill speed. Spatial (foot rotation, step width, stride and step length), temporal (stride and step times, duration of stance, swing and single and double support) and peak vertical ground reaction force variables were collected over a 30–second capture period, equating to an average of 52 ± 5 steps of steady–state walking. Testing was repeated one week following the initial trial and again, for a third time, 20 minutes later. Repeated measures ANOVAs within a generalized linear modelling framework were used to assess between–session differences in gait parameters. Agreement between gait parameters measured within the same day (session 2 and 3) and between days (session 1 and 2; 1 and 3) were evaluated using the 95% repeatability coefficient.ResultsThere were statistically significant differences in the majority (14/16) of temporal, spatial and kinetic gait parameters over the three test sessions (P < .01). The minimum change that could be detected with 95% confidence ranged between 3% and 17% for temporal parameters, 14% and 33% for spatial parameters, and 4% and 20% for kinetic parameters between days. Within–day repeatability was similar to that observed between days. Temporal and kinetic gait parameters were typically more consistent than spatial parameters. The 95% repeatability coefficient for vertical force peaks ranged between ± 53 and ± 63 N.ConclusionsThe limits of agreement in spatial parameters and ground reaction forces for the treadmill system encompass previously reported changes with neuromuscular pathology and footwear interventions. These findings provide clinicians and researchers with an indication of the repeatability and sensitivity of the Zebris treadmill system to detect changes in common spatiotemporal gait parameters and vertical ground reaction forces.

Intra-rater repeatability of gait parameters in healthy adults during self-paced treadmill-based virtual reality walking

“…The current study indicates that the key spatial-temporal gait parameters had excellent ICC values (>0.88) and relatively small SEM and MDC values (<0.055 & <0.153 measurement units, respectively), which were inspected visually by using the 'Bland-Altman' graphs. These test-retest repeatability findings are comparable with other previously reported reliability findings for spatial-temporal gait during both over-ground (Stolze et al 1997;Paterson et al 2008;Meldrum et al 2014) and self-selected speed treadmills (Owings and Grabiner 2004;Faude et al 2012;Reed et al 2013;Liu et al 2016). The MDC values for spatial-temporal gait revealed relatively small amounts of variability made by the GRAIL system, which are sufficient to detect real changes over time.…”

“…These treadmills offer potential advantages for advancing gait analysis in both clinical and research settings, by recording multiple consecutive strides in a small space (Belli et al 2001;Goldberg et al 2008;Reed et al 2013). However, walking on a treadmill at fixed speed with the absence of visual flow raises the concern over whether gait is being compensated for by maintaining fixed speed (Sheik-Nainar and Kaber 2007;Terrier and Dériaz 2011;Sloot et al 2014b).…”

The effect of intracortical bone pin application on kinetics and tibiocalcaneal kinematics of walking gait

“…These effect magnitudes were considered subtle, compared to the random fluctuations expected from repeated measures in this type of experimental design [21,22]. The most prominent differences between SKIN and PIN occurred in kinematic data with up to 25% of ROM (~2-3°).…”

Lower material stiffness in rupture-repaired Achilles tendon during walking: transmission-mode ultrasound for post-surgical tendon evaluation

“…The treadmill belt speed was adjustable at intervals of 0.1 km/h between speeds of 0.2 and 22 km/h. Mean within-subject coefficients of variation for repeated measures of spatiotemporal gait parameters during walking in healthy adults are typically <10% [34].…”

“…Each patient's "comfortable" walking speed was determined at the outset of the acclimatisation session using a method outlined previously [34]. Following acclimatisation, TSOU in each AT, sagittal ankle motion, GRF, and basic spatiotemporal gait data were sampled synchronously using a common trigger.…”