Assessment of dynamic balancing responses following perturbations during slow walking in relation to clinical outcome measures for high-functioning post-stroke subjects

Abstract

Background: Generating appropriate balancing reactions in response to unexpected loss of balance during walking is important to prevent falls. The purpose of this study was to assess dynamic balancing responses following pushes to the pelvis in groups of post-stroke and healthy subjects. Methods: Forty-one post-stroke subjects and forty-three healthy subjects participated in the study. Dynamic balancing responses to perturbations triggered at heel strike of the left or right leg, directed in the forward, backward, inward and outward directions during slow treadmill walking were assessed. Responses of the healthy group provided reference values used to classify responses of the post-stroke group into two subgroups; one within the reference responses ("inside" subgroup) and the other that falls out ("outside" subgroup). A battery of selected clinical outcome measures (6-Minute Walk Test, 10-Meter Walk Test, Timed-Up-and-Go test, Four Square Step Test, Functional Gait Assessment, Functional Independence Measure and One-legged stance test) was additionally assessed in the post-stroke group. Results: The "inside" subgroup of post-stroke subjects was able to appropriately modulate centre-of-pressure and ground-reaction-force both under the impaired and non-impaired leg in response to perturbations. The "outside" subgroup of post-stroke subjects showed limited modulation of centre-of-pressure and ground-reaction-force under the impaired leg; instead stepping strategy was used in which the non-impaired leg was placed such as to make a longer step (forward perturbation), to make a shorter step (backward perturbation) or to make a cross-step (outward perturbation). Consequently, peak centre-of-mass displacements following perturbations were significantly higher in the "outside" subgroup compared to the "inside" subgroup. Responses in both subgroups following inward perturbations did not differ. Majority of clinical outcome measures moderately correlated with the peak centre-of-mass displacements for forward perturbations and exhibited weak correlations for other perturbation directions.

Dynamic balancing responses in unilateral transtibial amputees following outward-directed perturbations during slow treadmill walking differ considerably for amputated and non-amputated side

“…This indicates that their response mainly consisted of the stepping strategy. Delaying the corrective action resulted in higher COM displacement, which is in agreement with findings from other perturbation studies conducted in subjects without amputation and post-stroke subjects [ 12 , 26 , 44 ]. These findings support our hypotheses.…”

“…60% of gait cycle) and into the “stepping” periods (from left foot strike to the next right foot strike or from right foot strike to the next left foot strike—from approx. 60 to 100% of gait cycle) [ 44 ]. In both periods and separately for unperturbed and outward-directed perturbed walking they were normalized to the duration of each period to allow visual comparison between different sub-phases of the in-stance and stepping periods of the gait cycles.…”

Development and Evaluation of BenchBalance: A System for Benchmarking Balance Capabilities of Wearable Robots and Their Users

“…One of the main advantages of the BenchBalance system is that it is a low-cost and portable solution that gives a high versatility to the experimenter compared to other existing approaches, which consist of robotic devices that are complex and stationary, requiring structured experimental environments [ 17 , 18 , 19 ]. Its use is not restricted to even-ground laboratory conditions, which opens a wide range of options to assess balance in unstructured and challenging environments.…”

“…One class of these devices is extensively used to test the ability of balance control by applying a controlled external disturbance such as a push against the body [ 17 , 18 , 19 ]. However, these robotic devices are generally expensive, complex, and present several limitations when being used with human wearing wearable devices: for instance, problems with the fixation of the testing device to the human body when a wearable exoskeleton is being worn.…”

One-year intradialytic leg exercises with resistance bands and fat mass increase in elderly hemodialysis patients: a retrospective study

“…In order to support the adequacy of the exercises, we performed 10-m walk test (10MWT), timed up and go test (TUG) [ 17 ], and measured percent knee extension muscle power to dry body weight (weight bearing index, WBI) [ 18 ] at baseline, 3 months, 6 months, and 1 year after baseline. These tests were examined on non-dialysis day.…”