Ji-Eun Cho’s research while affiliated with Methodist Rehabilitation Center and other places

Introduction Many of the patients using ankle–foot orthoses (AFOs) experience poor fit, pain, discomfort, dislike of the aesthetics of the device, and excessive range of motion restrictions, which diminish the use of AFOs. Although 3D-printed ankle–foot orthoses (3D-AFOs) affect patient satisfaction and overall gait functions such as ankle moment, joint range of motion (ROM), and temporal-spatial parameters, the material properties and manufacturing process of 3D-AFOs are still diverse; the clinical effects of community ambulation using 3D-AFOs and satisfaction in patients with stroke are poorly understood. Case description Case 1: A 30-year-old man, with a history of right basal ganglia hemorrhage, presented with marked foot drop and genu recurvatum. Case 2: A 58-year-old man, with a history of multifocal scattered infarction, presented with an asymmetrical gait pattern due to abnormal pelvic movement. Case 3: A 47-year-old man, with a history of right putamen hemorrhage, presented with recent poor balance and a prominent asymmetrical gait pattern due to increased ankle spasticity and tremor. All patients could walk independently with AFOs. Interventions and outcomes Gait was assessed under three walking (even, uneven, and stair ascent/descent) and four AFO (no shoes, only shoes, shoes with AFOs, and shoes with 3D-AFOs) conditions. After 4 weeks of community ambulation training with 3D-AFO or AFO, the patients were followed up. Spatiotemporal parameters; joint kinematics; muscle efficiency; clinical evaluations including impairments, limitations, and participation; and patient satisfaction with wearing 3D-AFO were evaluated. Results and conclusion 3D-AFOs were suitable for community ambulation of patients with chronic stroke and effective on step length, stride width, symmetry, ankle range of motion, and muscle efficiency during even surface walking and stair ascent in patients with chronic stroke. The 4-week community ambulation training with 3D-AFOs did not promote patient participation; however, it increased ankle muscle strength, balance, gait symmetry, and gait endurance and reduced depression among patients with a history of stroke. The participants were satisfied with 3D-AFO's thinness, lightweight, comfortable feeling with wearing shoes, and gait adjustability.

Objectives Stroke patients suffer from ankle joint deformities due to spastic ankle muscles. This study evaluated the viability of using 3D scanned surface images of the feet of stroke victims to visually assess the deformities of a hemiparetic foot and investigated the influences of deformed ankle joints on gait kinematics. Methods A total of 30 subjects with stroke-induced hemiparesis and 11 age-matched healthy controls completed the clinical assessments. We analyzed their feet's morphometric characteristics using a 3D scanner, identified convenient anthropometric measurements, and conducted gait trials on even and uneven terrains. The 3D foot morphometric characteristics were evaluated using the geometric morphometrics method (GMM). Results Results showed that there were significant differences in bilateral foot shapes between the chronic stroke patients and healthy controls and between the paretic and non-paretic sides in the chronic stroke patients. In stroke patients, those with the smaller medial malleoli's vertical tilt angles showed significantly different ankle ranges of motion of dorsi-/plantar flexion during gaits on uneven terrains (p = 0.009). In addition, those with the greater medial malleoli's vertical tilt angles showed significantly different ankle ranges of motion of inversion/eversion during gaits on even and uneven terrains (p < 0.05). Conclusion Using 3D scanning technology, bilateral morphometric changes in the feet of chronic stroke patients were shown by GMM and the simple anthropometric measurements identified its shape deformities in the feet. Their possible effects on gait kinematics while walking on uneven terrains were investigated. Current methodology can be potentially useful in applying conventional productions of clinically manufactured, patient-fitted ankle-foot-orthosis in orthotics and prosthetics, and in detecting various unidentified pathological deformities in the feet.

Research Objectives - To improve the success rate to classify five different common walking conditions using various machine learning schemes. Design - Cross-sectional study. Setting - Walking Conditions during Community Walking; 1) Even surface; 2) Slope up; 3) Slope down; 4) Stair up; 5) Stair down. Participants Five healthy participants (37.8+/-7.25 yrs, F:4). Interventions - Walking over five different kinds of gait activities in community 1) walking on even surface; 2) Slope up; 3) Slope down; 4) Stair up; 5) Stair down - Analyzed post-processed data from sensors to classify the walking condition using machine learning from the signals of five Inertial Measurements Units (IMU), attached to waist, bilateral lower and upper legs, and smart insoles that measured total and hind/forefoot pressure distributtion. Main Outcome Measures - Analyzed 32934 gait data out of 47,033 training data using an Artificial Neural Netwroks (ANN), which was a Feed Forward Neural Network (FFNN) - Investigated 3 different initial sets of variables; 1) Validation ratio 10%, Test ratio 20%, 2) Validation data ratio 15%, Test data ratio 15%, 3) Validation ratio 20%, Test ratio 10%. Results - HIghest accuracy was achieved when validation ratio 15% and test data ratio 15% with the hidden layers was 1000 using FFNN (98.3%). Conclusions - 5 gait conditions were successfully categorized using FFNN with higher accuracy rate - Machine learning and senor network would be potentially useful to assist pathological gait, stroke, in the disabled by identifying walking condition in the community. Author(s) Disclosures All authors declare that no conflicts or lack thereof on this presentation.

Background: Individuals with stroke have impaired sensorimotor function of ankle. Objective: To investigate the effects of passive biaxial ankle movement training synchronized with electrical stimulation therapy (AMT-EST) on ankle proprioception, passive range of motion (pROM), and strength, balance, and gait of chronic stroke patients. Methods: Thirty-five stroke patients were randomized. The experimental group received a total of 20 AMT-EST sessions. The control group received only EST. Primary outcome measures were ankle functions. Secondary outcome measures were clinical assessments of motor, balance, and gait-related functions. All assessments were compared before and after the intervention. Results: The experimental group had significantly improved ankle dorsiflexor strength (p = 0.015) and ankle pROM during foot supination (p = 0.026) and pronation (p = 0.004) and clinical assessment (Fugl-Meyer Assessment of the lower extremities [FM-L], Berg Balance Scale, Timed Up and Go test, Fall Efficacy Scale, walking speed, and step length; all p < 0.05) values. The regression model predicting ankle proprioception showed significantly large effects (adjusted R2 = 0.493; p < 0.01) of the combined FM-L score and time since stroke. Conclusion: Biaxial AMT-EST resulted in better ankle pROM and strength than conventional EST. Ankle proprioception was not significantly improved after AMT-EST and was predicted by the FM-L score and time since stroke.

Objective To determine the main factor that predicts balance impairment in chronic stroke patients. Design Cross-sectional study. Setting Inpatient rehabilitation hospital and research laboratory. Participants A total of 57 patients (42 men, 15 women; mean age 55.7±12.2 years) with chronic symptoms following stroke. Interventions Not applicable. Main outcome measures Primary outcomes were ankle functions, including strength, range of motion, and proprioception, and balance, including Berg balance scale score and timed up and go test values. Secondary outcomes included gait kinematics, Fugl-Meyer scale score, and fall efficacy scale score. Results According to the cutoff score <46 on the Berg balance scale and the timed up and go test ≥13.5 s, 21 (36.8%) cases were classified as patients with balance impairment. Multivariable logistic regressions showed that ankle proprioception (odds ratio 3.49, 95% confidence interval 1.17–10.42) was a significant predictor when coupled with step length (odds ratio 0.00, 95% confidence interval 0.00–0.22). A cutoff score of 2.59 for the ankle proprioception value predicts balance impairment in stroke patients (area under the curve 0.784). Conclusion Ankle proprioception can be used to predict balance impairment in patients with stroke.

Introduction Ankle dysfunction in patients with stroke is a common but serious cause of balance and gait impairments. However, comprehensive paretic ankle training seldom exists. Thus, we investigated the effects of a bi-axial ankle muscle training program using visual feedback as a means to improve ankle strength and performance of functional activities in patients with stroke. Methods This study was a randomized controlled pilot trial with concealed allocation and assessor blinding and intention-to-treat analysis. Twenty-five patients with stroke and difficulty in walking (e.g., foot drop) or ankle muscle weakness receiving inpatient rehabilitation were included. The experimental group underwent ankle muscle training consisting of passive stretching, control of ankle muscles, and active-resistive strengthening using visual feedback for 40 min per day, 5 times per week for 4 weeks. The control group underwent ankle-related physical therapy, including ankle range-of-motion exercises. The amount of time for training was equal between the two groups. The outcome measurements were isometric ankle contraction force to assess the strength of ankle muscles, ankle proprioception, Fugl–Meyer lower extremity score, Berg balance scale score, walking speed, and ankle co-contraction index to assess muscle efficiency during gait. Results The analysis revealed significant between-group differences in the ankle muscle strength in each direction (P < 0.05), Fugl–Meyer score (P < 0.01), and stance-phase co-contraction index (P < 0.05). After training, the experimental group displayed significant within-group differences in the strength of the ankle muscles in each direction (P < 0.01), ankle proprioception (P < 0.05), and walking speed (P < 0.05). Conclusions Our findings demonstrate the significant short-term effects of ankle muscle training on strength, walking speed, and muscle efficiency in patients with chronic stroke.

Introduction: The objective of this study was to investigate the effect of passive biaxial ankle movement therapy on cortical activities. We hypothesized that biaxial ankle passive movement therapy changes patterns of sensorimotor cortical activations during ankle passive movement in chronic stroke. Methods: Seventeen patients with stroke were randomized to either experimental or control group. The experimental group (n=11) received the biaxial ankle training and the control group (n=6) had conventional therapies on affected ankle for a 30-minute daily session, five times a week for a month. Outcome measure was cortical activations by measuring the relative changes of oxygenated hemoglobin concentration between ipsilesional-/contralesional hemisphere during passive ankle movement using functional near-infrared spectroscopy(fNIRS)(Figure 1). All assessments was conducted before and after the training. Significance level was 0.05. Results: fNIRS images showed that ipsilesional oxyhemoglobin concentration increased around primary sensorimotor cortex (SMC) area in both control and experimental groups at the baseline ( P <0.05). After the ankle training, the ipsilesional oxyhemoglobin concentration significantly increased around somatosensory area for both control and experimental groups ( P <0.05, Figure 2). Conclusions: The results of this study showed significant ipsilesional cortical activation in SMC during biaxial ankle movement before and after the ankle training. Further study on the analysis according to the direction of ankle movement for both ipsilesional and contralesional brain area is needed.

Background Post stroke had both ankle sensory and motor impairments that affect ankle motor control. The purpose of this study was to investigate the effect of passive biaxial ankle movement training coupled with electrical stimulation (AMT-EST) on ankle proprioception, ankle strength, balance, and gait in chronic stroke. Methods Thirty-five stroke subjects were randomized to an experimental or control group, and 30 subjects completed the trials. The experimental group received AMT-EST on the affected ankle for 30 minutes a day, 5 times a week for 4 weeks, for a total of 20 sessions. The control group received electrical stimulation therapy on the affected ankle. The primary outcome measures were ankle proprioception, passive range of motion, and strength. The secondary outcome measures were balance and gait-related functional abilities. ResultsThe experimental group showed significant post-training improvement in ankle proprioception of eversion, the ankle passive range of motion (inversion and eversion), ankle strength (dorsiflexion, plantarflexion, inversion, and eversion) Fugl–Meyer Assessment (FM-A), Berg Balance Scale (BBS), Timed Up and Go test, Fall Efficacy Scale, and walking speed (p < 0.05). Significant group×time interactions were observed in ankle passive range of motion (inversion and eversion), ankle strength (dorsiflexion), and FM-A (p < 0.05). All ankle proprioception moderately correlated with ankle passive range of motion (eversion), ankle strength (dorsiflexion and eversion), the BBS, and FM-A (p < 0.05). Conclusions The findings suggest that AMT-EST can be proposed as an ankle rehabilitation program for people with chronic stroke with ankle sensorimotor impairment.Trial Registration  KCT0004688. Registered 01 Jan 2020

Background: This study was conducted to investigate the effect of passive biaxial ankle movement training synchronized with electrical stimulation therapy (AMT-EST) on ankle proprioception, ankle strength, balance, and gait in chronic stroke patients. We observed the changes in ankle sensorimotor function after stroke. Methods: Thirty-five stroke patients were randomized to an experimental or control group, and 30 patients completed the trials. The experimental group received AMT-EST on the affected ankle for 30 minutes a day, 5 times a week for 4 weeks, for a total of 20 sessions. The control group received electrical stimulation therapy on the affected ankle. The primary outcome measures were ankle proprioception, passive range of motion, and strength. The secondary outcome measures were balance and gait-related functional abilities. Results: Compared with those in the control group, the participants in the experimental group who received AMT-EST showed significant post-training improvement in ankle proprioception of eversion (P<0.05). The ankle passive range of motion (inversion and eversion), ankle strength (dorsiflexion, plantarflexion, inversion, and eversion), and functional abilities (Fugl–Meyer Assessment, Berg Balance Scale, Timed Up and Go test, Fall Efficacy Scale, and walking speed) significantly improved in the experimental group (P<0.05). Significant group×time interactions were observed in ankle passive range of motion (inversion and eversion), ankle strength (dorsiflexion), and Fugl–Meyer Assessment (P<0.05). All ankle proprioception moderately correlated with ankle passive range of motion (eversion), ankle strength (dorsiflexion and eversion), the Berg Balance Scale, and Fugl–Meyer Assessment (P<0.05). Conclusions: Biaxial AMT-EST effectively increased ankle proprioception, range of motion, strength, and functional abilities in chronic stroke patients. These findings suggest that AMT-EST can be proposed as a novel ankle rehabilitation program for chronic stroke patients with ankle sensorimotor impairment. Trial registration: This study was approved by the Institutional Review Board at a rehabilitation hospital (NRC-2017-04-035, National Rehabilitation Center, Seoul, South Korea) and retrospectively registered at a clinical trial registry on January 31, 2020 (CRIS, KCT0004688, https://cris.nih.go.kr/).