https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/390 2026-07-24T09:13:27Z 2026-07-24T09:13:27Z Yun, Yeo Joon Jang, Seong Ho Park, Jae Hyeon Choi, Seung Yoon Lee, Ji Woo Han, Seung Hoon https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/213294 2026-06-16T05:30:35Z 2026-05-01T00:00:00Z

Title: Lesion-Specific Clinical Implications of Oral Hesitation After Stroke: A Comparative Study of Frontal Versus Parietal Lobe Lesions Authors: Yun, Yeo Joon; Jang, Seong Ho; Park, Jae Hyeon; Choi, Seung Yoon; Lee, Ji Woo; Han, Seung Hoon Abstract: Background and Objectives: Whether post-stroke oral hesitation carries different clinical implications by lesion location is unclear. We compared oral hesitation and its relationship with chewing, cognition, and aspiration risk between frontal and parietal lobe stroke. Materials and Methods: We retrospectively analyzed 242 patients (35 frontal, 207 parietal) from 946 consecutive stroke admissions (2016–2020) with isolated lesions and videofluoroscopic swallowing study within one month. Oral hesitation, chewing, Clinical Dysphagia Scale (CDS), and Mini-Mental State Examination (MMSE) were recorded. Penetration-Aspiration Scale (PAS) scores were categorized as Normal (1), Penetration (2–5), or Aspiration (6–8). Multivariable logistic regression adjusting for age, sex, stroke type, and lesion side was performed. Firth’s penalized estimation was used for models with quasi-separation. Results: Groups were demographically comparable in age (68.1 ± 15.0 vs. 71.7 ± 12.2 years; p = 0.206) and female sex (48.6% vs. 42.0%; p = 0.590). Oral hesitation was significantly more prevalent in the frontal group (liquid: 80.0% vs. 23.2%, p < 0.001; semisolid: 68.6% vs. 26.6%, p < 0.001). Frontal patients scored worse on six of seven CDS subcomponents (p < 0.01), yet chewing was uncorrelated with oral hesitation or residue (p > 0.3), unchanged after MMSE adjustment. In parietal patients, chewing correlated with all outcomes (ρ = 0.19–0.30, p < 0.01). In parietal stroke, oral hesitation was linked with liquid aspiration (64.3% vs. 35.7%; OR = 3.25, p = 0.001) and semisolid airway invasion (OR = 2.70, p = 0.005); these associations remained significant after multivariable adjustment and FDR correction. No such association was detected in the frontal group, although this finding is limited by the smaller sample size. Conclusions: Oral hesitation may carry different clinical implications by lesion site. In parietal stroke, it was associated with chewing impairment and higher aspiration risk, suggesting a possible sensorimotor contribution. Frontal group findings were underpowered and should be considered exploratory. Lesion-specific interpretation warrants larger-cohort confirmation.

2026-05-01T00:00:00Z Yun, Yeo-joon Park, Jae Hyeon Jang, Minkyu Choi, Ji-woong Jang, Seongho https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/219205 2026-07-16T05:00:19Z 2026-03-01T00:00:00Z

Title: Immediate effects of ankle–foot orthosis on gait coordination and kinematics in subacute stroke Authors: Yun, Yeo-joon; Park, Jae Hyeon; Jang, Minkyu; Choi, Ji-woong; Jang, Seongho Abstract: Background: Ankle–foot orthoses (AFOs) are commonly prescribed after stroke, yet their immediate effects on bilateral hip–knee coordination and joint-specific contributors to functional gains are unclear. Research question: What are the immediate effects of AFO use on bilateral coordination and joint-level kinematics, and which changes relate to performance gains? Methods: Forty-eight individuals with subacute stroke (mean age 57.9 ± 13.9 years; 28 men/20 women; FAC median 3.0) performed overground 10-m trials under pre-AFO and immediate post-AFO conditions (no acclimatization); eight had two measurements (56 pre–post sets). A prefabricated semi-rigid AFO (UD-Flex, anterior shell) was fitted on the paretic limb. Seven inertial-measurement units recorded spatiotemporal metrics, phase-specific (stance/swing) peak angles, and hip–knee cyclogram metrics. Condition differences were expressed as Δ = post − pre. Elastic-net selection followed by ordinary least squares identified predictors of Δ velocity, Δ cadence, and Δ hip/knee ROM. Results: AFO use was associated with a small increase in walking speed (+0.01 m/s; p = 0.01), below MCID, whereas cadence and stride time were unchanged On the paretic limb, swing-phase peak hip flexion (−3.1°), knee flexion (−4.4°), and ankle dorsiflexion (−2.3°) decreased; contralateral peaks showed no significant change. Cyclogram geometry was largely preserved. Predictive models linked faster walking to greater non-paretic hip/knee excursions and paretic-ankle change (adjusted R²=0.36). Cadence related positively to non-paretic knee and paretic hip excursions and negatively to paretic-ankle change. Significance: AFO use was associated with reduced paretic swing-phase peak flexion and ankle stabilization, coinciding with a modest, sub-MCID speed gain. Findings support training that pairs paretic-ankle stability with non-paretic propulsion, while recognizing the limited clinical magnitude of the immediate effect.

2026-03-01T00:00:00Z Park, Yong Seok Yu, Yeon Woo Cha, Hari Lee, Joon Seok Yoon, Chan Kim, Byung-Hoon Park, Jae Hyeon Lee, Ki-Kwang https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/211130 2026-03-10T02:00:19Z 2026-02-01T00:00:00Z

Title: Verification of Markerless Gait Analysis: Multi-Camera and Single-Camera Approaches in Comparison to Marker-Based Gait Analysis Authors: Park, Yong Seok; Yu, Yeon Woo; Cha, Hari; Lee, Joon Seok; Yoon, Chan; Kim, Byung-Hoon; Park, Jae Hyeon; Lee, Ki-Kwang Abstract: Background and Objectives: This study aimed to verify the validity of markerless gait analysis using both single-camera markerless system (S-ML) and multi-camera markerless system (M-ML) approaches by comparing them with a gold-standard marker-based system (MB). Materials and Methods: Sixteen healthy adults walked at their gait speed, and their gaits were simultaneously analyzed using three systems: S-ML, M-ML, and MB. Intraclass correlation coefficients were used to assess the reliability of the spatiotemporal parameters, and the root mean squared error (RMSE) was calculated to quantify the kinematic differences relative to the MB systems. Results: Both S-ML and M-ML demonstrated good-to-excellent reliability in spatiotemporal parameters, including step length, stance time, and gait speed, whereas stride length and swing time measured by S-ML revealed moderate reliability. In terms of joint kinematics, S-ML demonstrated a performance comparable to that of M-ML, particularly at the hip and knee in the sagittal plane. For certain parameters, such as knee abduction/adduction in the frontal plane, the S-ML demonstrated lower RMSE values than M-ML. In contrast, the ankle joint angles estimated using S-ML exhibited reduced agreement. Conclusions: In conclusion, markerless gait analysis can serve as an alternative to conventional gait analysis. However, certain parameters need to be improved.

2026-02-01T00:00:00Z Jang, Seongho Lee, Shi-Uk Yun, Yeo Joon https://scholarworks.bwise.kr/hanyang/handle/2021.sw.hanyang/213060 2026-06-05T06:00:12Z 2026-02-01T00:00:00Z

Title: Deep Convolutional Neural Network Analysis of Biomechanical Gait Improvements Following Ankle-Foot Orthosis Use in Stroke Patients Authors: Jang, Seongho; Lee, Shi-Uk; Yun, Yeo Joon Abstract: Background & Objective: Advanced computational approaches, such as deep convolutional neural networks (DCNN), provide new opportunities for objectively classifying and interpreting complex biomechanical gait improvements following Ankle-Foot Orthosis (AFO) use in stroke rehabilitation. This study aimed to evaluate the efficacy of DCNN models in distinguishing affected versus control gait patterns and identifying subtle biomechanical improvements after AFO use, utilizing Gradient-weighted Class Activation Mapping (Grad-CAM) for interpretability.Materials and Methods: Gait data from 48 stroke patients (56 datasets) were collected pre- and post-AFO using inertial measurement units. Additionally, an extensive control dataset comprising 5,826 gait samples from 828 healthy individuals, previously validated was included to train and validate the DCNN model. Raw IMU sensor data underwent rigorous preprocessing including normalization, alignment, and segmentation into fixed-length sequences. Multi-plane hip-knee cyclogram data were transformed into numerical arrays representing sagittal, coronal, and transverse joint angles. Clinical covariates including age, sex, height, and weight underwent Z-score normalization for standardization.The DCNN model was developed and validated for two primary tasks: (1) distinguishing affected stroke gait from normal gait patterns, and (2) detecting subtle biomechanical gait improvements post-AFO. Grad-CAM visualizations identified critical gait phases significantly enhanced by AFO use.Results: The DCNN model achieved exceptional accuracy (99.9%), precision (100%), recall (100%), and F1-score (100%). Grad-CAM visualizations highlighted key biomechanical improvements, particularly increased hip and knee flexion during initial swing, improved knee extension and hip stability at terminal swing to initial contact transition, and enhanced joint stability during mid-stance phases. Notably, only two of 28 patients exhibited gait patterns approaching normal following AFO use, indicating a need for individualized rehabilitation strategies beyond orthotic support.Conclusion: The DCNN analysis successfully identified and visualized clinically relevant biomechanical gait improvements, underscoring its utility for precision medicine and individualized stroke rehabilitation strategies.

2026-02-01T00:00:00Z