• Journal of the Institute of Convergence Signal Processing
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• v.25 no.2
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• pp.67-76
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• 2024

Various types of assistive devices have been developed for upper limb amputees over the years, with myoelectric prosthesis particularly aimed at improving user convenience by enabling a range of hand gestures beyond simple grasping, tailored to the size and shape of objects. In this study, we developed a five-finger myoelectric prosthesis mimicking human hand size and finger movements, utilizing motor and worm gear mechanisms for stable and independent operation. Based on this, we designed a control system for independent finger control through electromyographic signal input, proposed a state transition-based hand gesture conversion algorithm by selecting representative eight hand gestures and defining conversion condition parameters. We introduced training and usability evaluation methods, and conducted usability assessments among upper limb amputees using dedicated tools, confirming the potential for commercial application of the algorithm and observing adaptive capabilities and high performance through iterative evaluations.

• Physical Therapy Rehabilitation Science
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• v.11 no.2
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• pp.145-153
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• 2022

Objective: The purpose of this study was to evaluate the Electromyography (EMG) of the upper limb during reaching tasks according to two heights in the sitting position. Design: Cross sectional design Methods: Fifteen hemiplegia, fifteen elderly, and fifteen healthy subjects have participated in this study. The targets (90% length of the subject's arm) were located at the two heights (the eye and xiphoid process). We have recorded EMG signals of seven upper limb muscles (anterior deltoid (AD), posterior deltoid (PD), pectoralis major (Pec), infraspinatus (Inf), supraspinatus (Sup), biceps brachii (Bi), triceps brachii (Tri)). The dependent variables were movement time(s), modulation ratio, working ratio, and the co-contraction ratio of the hemiplegia, elderly, and healthy at the reaching task. Two-way repeated-measures ANOVA (2-heights) was analyzed with the LSD post hoc test. Results: The study results were as follows: (1) The movement time to the target during reaching movement was significantly longer for the hemiplegia and elderly groups compared to the healthy group. (2) The modulation rate was significantly higher at eye height than the xiphoid height in AD, PD, Pec, Inf, Bi muscles, and the hemiplegia group and elderly group were significantly lower than the healthy group. Additionally, the modulation ratio showed a significant interaction between heights and groups. Conclusions: It is expected that the variables using the muscle contraction characteristics, the evaluation method of this study, can be used as an electromyography-based feedback method that can be objectively evaluated and quantified in clinical practice.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.11
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• pp.960-966
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• 2016

This paper proposes a new concept of a soft and wearable upper-limb exoskeleton. A novel actuation principle, called the twisted string actuation principle, is implemented to make it lightweight, soft, and therefore easily wearable. Its power transmission mechanism and harness are designed to be soft and wearable, yet have enough control accuracy for rehabilitation. In addition to force transmission optimization, a speed enlargement mechanism is newly introduced in order to increase the contraction speed of the twisted string actuation mechanism by sacrificing the unnecessarily large gear reduction ratio of the twisted string mechanism. A prototype has been tested for mirroring therapy, and the feasibility of the proposed mechanism has been shown through a sufficiently accurate tracking performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.292-299
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• 2019

This study was conducted to investigate the effects of therapeutic climbing training on upper limb function and quality of life of stroke patients and to suggest possibilities for clinical intervention. This study investigated 14 stroke patients who were assigned to either a treatment climbing training group or a control group (n=7 each). The experimental groups performed general physical therapy and occupational therapy. In addition, therapeutic climbing training using the Potsdam model was conducted for 30 minutes three times a week for 6 weeks. The control group performed general physical therapy and occupational therapy. A manual function test was used to evaluate upper limb function, and a short form 36-item questionnaire was used to evaluate quality of life. The results showed that there was a significant difference in upper limb function of the experimental group according to time (p<0.05). There was also a significant difference in the quality of life according to time in the experimental group, and a significant difference in quality of life between the experimental group and the control group (p<0.05). Therapeutic climbing training by stroke patients positively affected quality of life by increasing the SF-36 scores and upper limb function. Taken together, these findings confirmed that training using therapeutic climbing is valuable for rehabilitation and clinical intervention of stroke patients.

• Therapeutic Science for Rehabilitation
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• v.11 no.3
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• pp.37-50
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• 2022

Objective : This study aimed to investigate the use of electromyography (EMG) to evaluate upper limb movement or function in stroke patients. Methods : We reviewed papers published in journals between January 2018 and December 2021 using PubMed, EMBASE, Scopus, RISS, and KISS. The main keywords of databases were ('stroke' OR 'hemiplegia') AND ('EMG' OR 'electromyography' OR 'electromyogram' OR 'muscle activity') AND ('Upper limb' OR 'Hand'). Results : Fifteen studies were selected, most of which evaluated muscle activity. Interventions performing tasks related to activities of daily living (ADLs), using assistive technology, and interventions that provide repetitive training were most frequently applied. Conclusions : When evaluating upper limb functions using electromyography, it is meaningful to present an evaluation that can be used according to the purpose of the study and to provide a basis for setting up interventions that can utilize electromyography during evaluation.

• Physical Therapy Rehabilitation Science
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• v.5 no.3
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• pp.149-154
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• 2016

Objective: The arm swing is associated with gait ability in healthy young adults. The purpose of this study was to examine the effects of arm swing during gait in healthy young adults. Design: Cross-sectional study. Methods: Forty-five subjects without any orthopedic or neurological injuries participated in this study. All subjects performed all three conditions according to the arm swing type as follows: first procedure (condition 1), walking as usual without arm swing constraint; second procedure (condition 2), constraint of dominant arm swing walking as usual; third procedure (condition 3), constraint of both arm swing walking as usual. Gait parameters such as gait velocity, stride length, cadence, step time, single limb support, and double limb support were measured in all arm swing conditions performed randomly, with the mean value obtained from three measurements. A rest period of 5 minutes was given to prevent repetition of each condition and learning effect. All data was analyzed using repeated measures ANOVA to notice the changes between arm swing conditions. Results: Within walking conditions, significant difference of gait velocity, stride length, cadence, and double limb support was noticed (p<0.05), except step time and single limb support. Gait velocity and stride length were significant reduced, and in cadence and double limb support were increased (p<0.05). Condition 3 had the most significant decrease of gait ability compared with condition 1 (p<0.05). Conclusions: These finding suggested that constraint arm swing conditions reduced gait ability in healthy young adults. Also, these findings can be utilized as a reference to future studies that not only pelvic, knee and ankle, but also upper limb affect to gait ability.

• Therapeutic Science for Rehabilitation
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• v.8 no.4
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• pp.7-18
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• 2019

Objective : This systematic review aimed to investigate the impact of transcranial direct current stimulation combined with constraint-induced movement therapy (CIMT) in patients with stroke Methods : PubMed and NDSL databases were employed to review literature published between January 2009 and December 2018. The main search terms were "Transcranial direct current stimulation" or "tDCS," "Constraint-induced movement therapy" or "CIMT," "Upper extremity function," "Upper limb," and "Stroke." Based on the inclusion and exclusion criteria, 6 articles were selected. Furthermore, intervention effects on upper extremity function, activities of daily living, and cortical activity were assessed. Results : The current intensity, application time, and protocol of the CIMT varied the between studies. However, the intervention procedures to perform CIMT immediately after transcranial direct current stimulation was the same. Transcranial direct current stimulation combined with CIMT was effective in improving upper limb function and activities of daily living in patients with stoke and had a significant effect on cerebral cortex activation. Conclusions : This study provides information on transcranial direct current stimulation combined with CIMT for use by clinical therapists. Further studies are needed to standardize the stimulation time, current intensity, and electrode attachment position. Furthermore, randomized controlled trials, including long-term follow up, are needed for larger populations using the most appropriate CIMT protocol.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.3
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• pp.253-259
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• 2017

Conventional upper extremity rehabilitation paradigm after brain injury has several shortcomings that is monotonous, simple, and repetitive in exercises over a long period of time, thereby causing training efficiency to decline as a consequence of low interest and participation. To resolve this issue, this paper proposes a new rehabilitative program integrating a wearable device integrated with EMG and motion sensor and a mobile game for the upper limbs' rehabilitative training. The developed wearable device is manufactured in the form of band, making it easy to wear. The mobile game is designed to enable rehabilitative training through games reflective of flexion, extension, abduction, and adduction identified by motion sensors along with grasp motion recognized by EMG signals measured from the wearable device. It also provides a tailored rehabilitative environment suitable for individual patients based on difficulty adjustments. As a consequence of applying the developed program to 14 brain injury in need of the upper limb rehabilitation and taking surveys on the utility of the developed rehabilitative program, the responses indicated that the developed rehabilitative program is far much more interesting and fun than the conventional rehabilitative program, further to the desire of those surveyed to reuse the developed program in the future.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.3
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• pp.123-130
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• 2018

Purpose : The purpose of this study was to investigate the effects of mirror therapy with functional electrical stimulation to improve upper extremity motor function and activities of daily living (ADL) in stroke patients. Method : Thirty patients were randomly assigned to the experimental and control groups 15 patients in each. All subjects received the general occupational therapy consisting of five 30 min sessions per week for 8 weeks, in addition to 30 min of mirror therapy with functional electrical stimulation for the experimental group and 30 min of functional electrical stimulation for the control group for each session. To measure the functions of the upper limb and performance capacities in ADL, the Fugl-Meyer Assessment (FMA), and Manual Function Test (MFT), Modified Barthel Index (MBI) were used before and after the interventions. Results : Both the experimental and control groups showed a statistically significant increase in post-treatment FMA, MFT and MBI scores compared to their pre-treatment scores (p<.05). In addition, intergroup comparisons revealed a statistically significant increase in the scores of all assessments for the experimental group compared to those for the control group (p<.05). Conclusion : Based on these results, it is reasonable to conclude that mirror therapy with functional electrical stimulation is an effective intervention for improving upper limb motor function and ADL performance in stroke patients.

• Journal of Biomedical Engineering Research
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• v.43 no.4
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• pp.241-250
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• 2022

It is known that chronic pain and injury of upper limb joint tissue in manual wheelchair users is usually caused by muscle imbalance, and the propulsion speed is reported to increase this muscle imbalance. In this study, kinematic variables, electromyography, and ultrasonographic images of the upper limb were measured and analyzed at two different propulsion speeds to provide a quantitative basis for the risk of upper extremity joint injury. Eleven patients with spinal cord injury for the experimental group (G_E) and 27 healthy adults for the control group (G_C) participated in this study. Joint angles and electromyography were measured while subjects performed self-selected comfortable and fast-speed wheelchair propulsion. Ultrasound images were recorded before and after each propulsion task to measure the acromiohumeral distance (AHD). The range of motion of the shoulder (14.35 deg in G_E; 20.24 deg in G_C) and elbow (5.25 deg in G_E; 2.57 deg in G_C) joints were significantly decreased (p<0.001). Muscle activation levels of the anterior deltoid, posterior deltoid, biceps brachii, and triceps brachii increased at fast propulsion. Specifically, triceps brachii showed a significant increase in muscle activation at fast propulsion. AHD decreased at fast propulsion. Moreover, the AHD of G_E was already narrowed by about 60% compared to the G_C from the pre-tests. Increased load on wheelchair propulsion, such as fast propulsion, is considered to cause upper limb joint impingement and soft tissue injury due to overuse of the extensor muscles in a narrow joint space. It is expected that the results of this study can be a quantitative and objective basis for training and rehabilitation for manual wheelchair users to prevent joint pain and damage.