• The Journal of Korean Physical Therapy
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• 제29권2호
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• pp.74-79
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• 2017

Purpose: The purpose of this study was to compare the effects of the FES-gait with augmented feedback training to the FES alone on the gait and functional performance in individuals with chronic stroke. Methods: This study used a pretest and posttest randomized control design. The subjects who signed the agreement were randomly divided into 12 experimental groups and 12 control groups. The experimental groups performed two types of augmented feedback training (knowledge of performance and knowledge of results) together with FES, and the control group performed FES on the TA and GM without augmented feedback and then walked for 30 minutes for 40 meters. Both the experimental groups and the control groups received training five times a week for four weeks. Results: The groups that received the FES with augmented feedback training significantly showed a greater improvement in single limb support (SLS) and gait velocity than the groups that received FES alone. In addition, timed up and go (TUG) test and six minute walk test (6MWT) showed a significant improvement in the groups that received FES with augmented feedback compared to the groups that received FES alone. Conclusion: Compared with the existing FES gait training, augmented feedback showed improvements in gait parameters, walking ability, and dynamic balance. The augmented feedback will be an important method that can provide motivation for motor learning to stroke patients.

• 한국운동역학회지
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• 제33권1호
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• pp.17-24
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• 2023

Objective: The purpose of this study was to investigate the effects of different frequency on of knee extensors muscle function during electrical muscle stimulation (EMS). Method: In this research, 40 subjects who have no musculoskeletal disorder, and less than a year workout experience were recruited in order to analyze effects of EMS with different stimulus frequency. Forty subjects were randomly divided into four groups of ten subjects in each group. A EMS training program with different frequencies (without EMS [WE], EMS with frequency 30 Hz [E30], EMS with frequency 60 Hz [E60], EMS with frequency 90 Hz [E90]) was assigned to each group. Throughout eight weeks of training, test subjects were simultaneously carried out knee extension exercises such as squat, leg extension, and leg-press while using EMS with different frequency (20 min, pulse width 250 ㎲, on-off ratio 1:1). Isokinetic knee extension strength, muscle activity of the rectus femoris (RF), the vastus medialis (VM), and the vastus lateralis (VL), and the median frequency of the RF, the VM, and the VL were collected and compared between pre and post training in order to find effects of applying EMS with different frequencies. For each dependent variable, a one-way ANOVA was to determine whether there were significant differences among four different conditions (p<.05). When a significant difference was found, post hoc analyses were performed using the contrast procedure. Results: When compared to WE and E90, E30 causes significant increase in isokinetic knee extension strength. No significant differences were found in EMG values across different EMS conditions. However, the median frequency of the VM in E30 was significantly increased than the corresponding value for WE. Conclusion: The results of this study showed that EMS training with 30 Hz frequency had positive effect on knee extensor. Based of the findings of the present study, EMS training with lower frequency may help the performer to focus on developing strength in knee extensor muscles.

• 대한물리의학회지
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• 제12권2호
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• pp.43-52
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• 2017

PURPOSE: This study aimed to compare the impact of exercise with that of functional electrical stimulation (FES) and transcutaneous electrical nerve stimulation (TENS) on muscle tone, calf muscle stiffness, and balance ability in patients with stroke. METHODS: Thirty patients with stroke were randomly divided into an FES group (n=15) and a TENS group (n=15), and a progressive task-oriented exercise was assigned to them. These exercises were performed non-synchronously from December 5, 2016 to January 31, 2017. Patients underwent TENS and simultaneously exercised for 30 minutes daily, 5 times a week for 4 weeks. To determine the effect of the interventions, muscle tone and stiffness of the medial and lateral region of gastrocnemius muscle were measured using the MyotonPRO instrument and balance was assessed using the Berg Balance Scale. RESULTS: Both groups revealed a significant decrease in muscle tone and stiffness of the medial part of gastrocnemius muscle before and after the interventions (p<.05). Berg Balance Scale scores increased significantly (p<.05). However, none of the other parameters were significantly different (p>.05). CONCLUSION: Our results prove that progressive task-oriented exercise along with FES and TENS decreases muscle tone and stiffness of the gastrocnemius muscle in patients with stroke and improves balance. TENS could serve as a complementary replacement for functional electrical stimulation for in-house training, as TENS poses less risk of muscle fatigue and has lesser contraindications than does functional electrical stimulation.

• 한국전문물리치료학회지
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• 제3권3호
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• pp.32-43
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• 1996

The purpose of this case study was to introduce functional electrical stimulation(FES) for paraplegic patients. FES provides the ability to rise from sitting to standing, maintenance of a standing position, and the ability to walk with a reciprocal gait. Six channels of electrical stimulation are sufficient for synthesis of a simple reciprocal gait pattern in these patients. During the double-stance phase, knee extensor muscles of both knees are stimulated, providing sufficient support for the body. Only one knee extensor muscle group is excited during the single-stance phase. The swing phase of the contralateral lower extremity is accomplished by eliciting the synergic flexor muscle response through electrical stimulation of afferent nerves. The transition from the double-stance phase to the swing phase is controlled by two hand switches used by the therapist or built into the handles of the walking frame for using by the patient. A twenty-five years old male was with a T9/T9 spinal cord injury due to a traffic accident and admitted to Yonsei Rehabilitation Hospital for comprehensive treatment. After 30 days of training using the Parastep(R) he was able to stand for 10 minutes. After 43 days, he was able to walk and at discharged he could walk for 100 meters.

• 한국소음진동공학회논문집
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• 제21권1호
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• pp.31-40
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• 2011

This paper examines the dynamic characteristics of a human carpal muscle through theoretical analysis and experiment. The carpal muscle was modeled as a 1-DOF vibration system and vibration response due to a ramp function force was calculated. The electromyogram signal corresponding to the muscle excitation force was measured, and the excitation force function of an envelope curve from the electromyogram signal was extracted. The ramp input function of electrical stimulation to the carpal muscle was applied by using a device for functional electrical stimulation, and the angular displacements corresponding to steady state response were measured. Theoretical calculations of the vibration response displacements were compared with the experimental results of the angular displacements, and have shown a good agreement with the result that is linearly proportional to the excitation force magnitude. As a result, the relationship between the input current of the electrical stimulation and the excitation force magnitude was inferred. The result was shown that it can be applied to develop rehabilitation training devices.

• 대한의용생체공학회:의공학회지
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• 제38권6호
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• pp.308-312
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• 2017

Skeletal muscle function plays a very important role in quality of life. However, skeletal muscle causes functional decline under aging or some diseases. Exercise and muscle training are good solutions to delay sarcopenia, but there are limitations to those who are uncomfortable in exercise. For this reason, alternative interventions for muscle sarcopenia are required, and many studies proved the increase of skeletal muscle mass by electrical stimulation. In conventional studies, however, mouse skeletal muscle cells have been mostly used in experiments to identify electrical stimulation conditions while human derived cells have not been frequently utilized in these studies. Stimulation used for rehabilitation has been uniformly treated without the consideration of aging. In addition, many studies have been used with conventional petri dish usually requiring many numbers of cells, which is not appropriate for rare. Moreover, they are not usually condition uniformity of electrical field. In this study, we have developed an electrical stimulation device which consumes a small amount of cells and can form a uniform electrical field. With the system, we analyzed the skeletal muscle differentiation and Myotube thickness depending on the electrical stimulation condition.

• 한국전문물리치료학회지
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• 제29권3호
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• pp.187-193
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• 2022

Background: Neuromuscular electrical stimulation (NMES) is a physical modality used to activate skeletal muscles for strengthening. While voluntary muscle contraction (VMC) follows the progressive recruitment of motor units in order of size from small to large, NMES-induced muscle contraction occurs in a nonselective and synchronous pattern. Therefore, the outcome of muscle strengthening training using NMES-induced versus voluntary contraction might be different, which might affect balance performance. Objects: We examined how the NMES training affected balance and proprioception. Methods: Forty-four young adults were randomly assigned to NMES and VMC group. All participants performed one-leg standing on a force plate and sat on the Biodex (Biodex R Corp.) to measure balance and ankle proprioception, respectively. All measures were conducted before and after a training session. In NMES group, electric pads were placed on the tibialis anterior, gastrocnemius, and soleus muscles for 20 minutes. In VMC group, co-contraction of the three muscles was conducted. Outcome variables included mean distance, root mean square distance, total excursion, mean velocity, 95% confidence circle area acquired from the center of pressure data, and absolute error of dorsi/plantarflexion. Results: None of outcome variables were associated with group (p > 0.35). However, all but plantarflexion error was associated with time (p < 0.02), and the area and mean velocity were 37.0% and 18.6% lower in post than pre in NMES group, respectively, and 48.9% and 16.7% lower in post than pre in VMC group, respectively. Conclusion: Despite different physiology underlying the NMES-induced versus VMC, both training methods improved balance and ankle joint proprioception.

• The Journal of Korean Physical Therapy
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• 제34권5호
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• pp.205-211
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• 2022

Purpose: This study investigated the effects of an intervention that combined the abdominal drawing-in maneuver and frequency-specific neuromuscular electrical stimulation on changes in trunk muscle activity, muscle fatigue, and balance in stroke patients. Methods: Thirty stroke patients were randomly assigned to two groups. Fifteen subjects were assigned to group I which performed the abdominal drawing-in maneuver combined with low-frequency neuromuscular electrical stimulation and the other 15 subjects to group II where the abdominal drawing-in maneuver was combined with high-frequency neuromuscular electrical stimulation. Muscle activity and fatigue were measured using surface electromyography before the intervention. Balance was measured using the Trunk Impairment Scale and re-measured after six weeks of intervention for comparative analysis. Results: Both groups showed a significant increase in muscle activity and balance (p<0.05), and there was no significant difference between the groups (p>0.05). In the changes in muscle fatigue, only the experimental group II showed a significant increase in muscle fatigue (p<0.05). The difference between the groups was statistically significant (p<0.05). Conclusion: It was confirmed that among stroke patients, the combination of the abdominal drawing-in maneuver and low-frequency neuromuscular electrical stimulation was more effective in changing the muscle activity and balance of the trunk by minimizing the occurrence of muscle fatigue compared to the combination of the abdominal drawing-in maneuver and high-frequency stimulation. These results can be used as basic data for clinical trunk stabilization training.

• 재활치료과학
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• 제7권1호
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• pp.63-77
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• 2018

목적 : 본 연구는 기능적 전기 자극을 병행한 과제 지향적 훈련이 불완전 경수 손상 환자의 손 기능에 미치는 영향을 알아보고자 하였다. 연구방법 : 대상자는 불완전 경수 손상 진단을 받은 성인 3명으로, ABA 설계를 사용하였으며, 연구기간 동안 기초선(A1) 5회기, 중재기(B) 20회기, 재기초선(A2) 5회기로 총 30회기 실시하였다. 중재기(B) 동안 기능적 전기 자극을 병행한 과제 지향적 훈련이 제공되었고, 모든 회기에는 손 기능을 평가하기 위해 상자와 나무토막 검사(Box and Block Test), 떨어지는 막대 잡기(Grip the falling bar)와 먹기 흉내 내기(Simulated feeding)를 측정하였으며, 기초선(A1) 전, 재기초선(A2) 후로 Canadian Occupational Performance Measure(COPM), Jebsen-Taylor Hand Function Test(JTHFT)와 Wolf Motor Function Test(WMFT)를 실시하여 중재 효과를 살펴보았다. 결과 : 모든 대상자는 상자와 나무토막 검사(Box and Block Test), 떨어지는 막대 잡기(Grip the falling bar)와 먹기 흉내 내기(Simulated feeding)를 통해 기초선(A1)보다 중재기(B)에서 우세 손 기능이 향상되었고, 재기초선(A2)에서 그 효과가 유지되었다. 재기초선(A2) 후 COPM, JTHFT와 WMFT의 결과, 우세 손 기능의 향상과 과제 수행도와 만족도의 향상을 보였다. 결론 : 기능적 전기 자극을 병행한 과제 지향적 훈련은 경수 손상 환자의 손 기능뿐만 아니라, 대상자가 선택한 훈련 과제의 과제 수행도와 만족도 향상에 효과적이다.

• 대한의용생체공학회:의공학회지
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• 제28권1호
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• pp.29-35
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• 2007

This study was designed to investigate the feasibility to utilize the electromyogram (EMG) for estimating the muscle torque. The muscle torque estimation plays an important role in functional electrical stimulation because electrical stimulation causes muscles to fatigue much faster than voluntary contraction, and the stimulation intensity should then be modified to keep the muscle torque within the desired range. We employed the neural network method which was trained using the major EMG parameters and the corresponding knee extensor torque measured and extracted during isometric contractions. The experimental results suggested that (1) our neural network algorithm and protocol was feasible to be adopted in a real-time feedback control of the stimulation intensity, (2) the training data needed to cover the entire range of the measured value, (3) different amplitudes and frequencies made little difference to the estimation quality, and (4) a single input to the neural network led to a better estimation rather than a combination of two or three. Since this study was done under a limited contraction condition, the results need more experiments under many different contraction conditions, such as during walking, for justification.