DOI: 10.5061/dryad.d7wm37q7w
title: Adapting spatiotemporal gait symmetry to electrical stimulation during treadmill walking

description: Individuals with neurological impairments often exhibit asymmetrical gait
 patterns. This study highlighted the potential of functional electrical
 stimulation (FES) to improve gait symmetry during treadmill training and
 investigated whether our proposed FES perturbation paradigm could induce
 gait adaptation concerning spatial and temporal gait symmetry in healthy
 subjects. In the FES perturbation paradigm, both legs received electrical
 pulses at the same period as the subjects’ initial stride duration, and
 the temporal gap between the two pulses for each leg was manipulated over
 7 minutes. Following this, subjects continued to walk for another 5
 minutes without FES. For the implicit trial (unconscious reaction to FES),
 subjects were asked to walk comfortably in response to the stimulation.
 For the explicit trial (conscious reaction to FES), subjects were asked to
 explicitly synchronize their toe-off phase to the stimulation. To examine
 the effects of the FES perturbation, we measured step length and stance
 time and then analyzed changes in step length and stance time symmetries
 alongside their subsequent aftereffects. In this study, regardless of
 whether subjects adapted their gait patterns to the electrical pulses
 explicitly or implicitly, a directional change was observed in stance time
 (temporal) symmetry under both conditions, with the right stance becoming
 longer than the left. The stance time asymmetry induced by FES
 perturbation resulted in a slight residual effect. No consistent trend of
 step length (spatial) symmetry changes was observed in either condition.
 This indicates that subjects may adapt their spatial gait patterns through
 diverse mechanisms. Our findings suggest that the applied FES perturbation
 strategy can induce adaptations in subjects’ temporal gait asymmetry,
 particularly while in stance. Further experiments would provide a deeper
 understanding of the mechanism behind subjects’ response to FES
 perturbations, as well as the long-term effects of these perturbations on
 the spatial and temporal aspects of gait symmetry.
description: All experiments were performed on a treadmill (Woodway USA,
 Waukesha, WI) equipped with supporting handrails to ensure the safety of
 subjects. All subjects were given an approximate 5-minute preparatory
 period to adjust to walking on the treadmill. Two motion-capturing markers
 were attached to the back of the subjects’ shoes and tracked by a
 camera-based motion-capturing system (Optotrak 3D Investigator, Norther
 Digital Inc. Canada). This system located the positions of the markers and
 sent the data to a PC in real time using a program developed with LabVIEW
 (National Instruments Corp., TX) to measure the subjects’ spatiotemporal
 gait parameters such as step length, stride period, and stance duration.
 In this study, the position of the most forward marker was designated as
 the heel strike position, while the most backward marker position was
 identified as the toe-off position. We determined the stride period by
 measuring the interval from one heel strike to the next, and the stance
 duration by measuring the interval from a heel strike to the subsequent
 toe-off. It is important to note that the actual instance of toe-off
 occurs slightly after the marker reaches its most backward position.
 Nonetheless, we adhered to these measurement criteria consistently,
 prioritizing the assessment of symmetry between the two legs.
description: # Adapting spatiotemporal gait symmetry to electrical stimulation during
 treadmill walking
 [https://doi.org/10.5061/dryad.d7wm37q7w](https://doi.org/10.5061/dryad.d7wm37q7w) The dataset includes asymmetry for step length, stance time, and double limb support time. The symmetry ratio was computed for each gait cycle by using the following formula: 100×(right leg measure – left leg measure)/(0.5×(right leg measure + left leg measure)). ## Description of the data and file structure Data were stored on each tab by different conditions (explicit and implicit conditions) and by different gait parameters (step length symmetry, stand time symmetry, and double limb support time symmetry). The experimental trial consisted of three states: a 4-min baseline period, a 7-min perturbation period, and a 5-min post-perturbation period. Gait symmetry values were calculated in successive 30-second intervals. Therefore, each row of the data set represents data obtained from a successive 30-second time window, and the columns represent data obtained from different subjects. ## Sharing/Access information NA ## Code/Software NA