• Journal of Preventive Medicine and Public Health
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• 제52권4호
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• pp.250-257
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• 2019

Objectives: Flatfoot, or low medial longitudinal arch, contributes to back and lower extremity injuries and is caused by weak abductor hallucis (AbdH) muscles. The purpose of this study was to investigate the effects of short foot exercise (SFE) alone or with neuromuscular electrical stimulation (NMES) on navicular height, the cross-sectional area (CSA) of the AbdH muscle, and AbdH muscle activity in flexible flatfoot. Methods: Thirty-six otherwise healthy people with flexible flatfoot were randomly assigned to a group that received SFE with placebo NMES treatment (the control group) or a group that received both SFE and NMES treatment (the experimental group). Each group received 4 weeks of treatment (SFE alone or SFE with NMES). Navicular height, the CSA of the AbdH muscle, and AbdH muscle activity were assessed before and after the intervention. Results: No significant differences were found in navicular height or the CSA of the AbdH muscle between the control and experimental groups, while AbdH muscle activity showed a statistically significant difference between the groups ($SFE=73.9{\pm}11.0%$ of maximal voluntary isometric contraction [MVIC]; SFE with $NMES=81.4{\pm}8.3%$ of MVIC; p<0.05). Moreover, the CSA of the AbdH muscle showed a statistically significant increase after treatment in the SFE with NMES group ($pre-treatment=218.6{\pm}53.2mm^2$ ; $post-treatment=256.9{\pm}70.5mm^2$ ; p<0.05). Conclusions: SFE with NMES was more effective than SFE alone in increasing AbdH muscle activity. Therefore, SFE with NMES should be recommended to correct or prevent abnormalities in people with flexible flatfoot by a physiotherapist or medical care team.

• 대한물리의학회지
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• 제13권4호
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• pp.67-74
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• 2018

PURPOSE: This study was conducted to investigate the effects of vibration frequency and amplitude on scapular winging during the knee push-up plus exercise. METHODS: A total of 26 female subjects with scapular winging were evaluated while performing the knee push-up plus exercise with no vibration, low-frequency/low-amplitude (5 Hz/3 mm) vibration, low-frequency/high-amplitude (5 Hz/9 mm) vibration, high-frequency/low-amplitude (15 Hz/3 mm) vibration, and high-frequency/high-amplitude (15 Hz/9 mm) vibration. The surface EMG of the serratus anterior (SA) muscle was compared between the vibration frequency and amplitude. The EMG amplitude was normalized using the maximal voluntary isometric contraction (MVIC). The statistical significance of the results was evaluated using one-way ANOVA. RESULTS: The SA muscle EMG values increased at low-frequency/low-amplitude vibration and at low-frequency/high-amplitude vibration compared to no vibration. Furthermore, the same values increased at high-frequency/low-amplitude vibration and high-frequency/high-amplitude vibration compared to no vibration. In general, a higher vibration frequency and amplitude was associated with higher EMG values of the SA muscle, with particularly greater increases observed during high-frequency/high-amplitude vibration. There was also a significant difference between each condition with a high-frequency/high-amplitude vibration (p<.05). CONCLUSION: This study suggests that there were remarkable clinical effect of the knee push-up plus exercise with vibration, which enhanced the SA muscle activation in persons with scapular winging. Furthermore, applying a higher vibration frequency and amplitude more effectively increased for increasing SA muscle activation.

• 한국전문물리치료학회지
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• 제28권2호
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• pp.101-107
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• 2021

Background: Studies suggest that induced emotional changes can affect the sensory-motor system involved in the practice of muscle activity and movement in physical aspects. Previous studies have shown focused on effects just feedback on muscle activity associated with emotions but rarely have focused induced emotional change on gross motor function such as muscle activity. Objects: The purpose of this study was to compare biceps activity and emotion that before and after viewing a video was induced positive or negative emotion. Methods: The study enrolled 34 healthy male and female who scored at normal points on the Center for Epidermiological Studies-Depression Scale. The study measured over two weeks, showing subjects pleasant and sad videos one by one in a week. We performed to measure the biceps brachii activity which is maximal voluntary isometric contraction (MVIC) and the visual analog mood scale (VAMS) scores before and after one week. The significance level was set to α = 0.05. Results: There was no significant difference in muscle activity of the biceps brachii before and after each video was viewed (p > 0.05). However, the visual analogue mood scale showed an increase in VAMS after viewing each video (p < 0.05). Conclusion: We figured out induced emotional changes are cause actual emotional changes but there are no differences in muscle activity. In this research, watching the video with a short time looks like insufficient to change muscle activity. Nevertheless, there might be different when we check various muscles with sufficient time for viewing the video. Further study is needed to measure a variety of muscles with more time for viewing the video.

• Physical Therapy Rehabilitation Science
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• 제9권4호
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• pp.287-294
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• 2020

Objective: This study aimed to investigate the effects of an ultrasound-based bar graph proportional to the quadriceps muscle thickness as a real-time visual feedback training tool in the elderly. Design: Cross-sectional study. Methods: Twenty-four elderly persons participated in this study and were randomly divided into three groups: oral training group (n=8, group 1), ultrasound imaging group (n=8, group 2), and graph group (n=8, group 3). In the pre condition, all participants performed maximal voluntary isometric contraction (MVIC) of the quadriceps with knee extension three times with oral training. In the post condition, group 1 performed MVIC of the quadriceps with oral training, group 2 performed MVIC of the quadriceps with real-time visual feedback using ultrasound imaging, and group 3 performed MVIC of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness, three times for all groups. Muscle thickness, activity (mean, peak), tone, stiffness, logarithmic decrement, relaxation, and creep were measured in both conditions in all participants. Results: Visual feedback with a bar graph showed significant effects on muscle thickness, mean muscle activity, and peak muscle activity compared with oral training and visual feedback with ultrasound imaging (p<0.05). Conclusions: Isometric training of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness may be more effective than other methods in improving muscle thickness and muscle activity. This study presented a tool that can help increase muscle thickness in the elderly.

• PNF and Movement
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• 제20권2호
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• pp.179-187
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• 2022

Purpose: The purpose of this study was to determine the asymmetrical difference between the use of leg muscles on the surgical and non-surgical sides during initial lower extremity ergometer exercise after unilateral knee arthroplasty. Methods: Twelve elderly patients diagnosed with degenerative arthritis of the knee and who underwent unilateral arthroplasty were included in this study. The leg length of each subject was taken into account when setting the application distance of the lower extremity ergometer. The same pedal resistance, strength, and speed were used for all the subjects. The total angle of use of the ergometer (360°) was analyzed by dividing it into an extension section and a flexion section. Using a surface electromyography system, the activities of the muscles of the surgical and non-surgical sides were converted into maximal voluntary isometric contraction (MVIC) and analyzed using the paired t-test. Results: When the activities of the muscles on the surgical and non-surgical sides were compared, it was found that the rectus femoris and biceps femoris had significant differences in the flexion and extension sections (p < .05), and that the tibialis anterior significantly differed in the flexion section (p < .05). There was no significant difference in the extension section of the tibialis anterior muscle, or in the flexion and extension sections of the gastrocnemius (p >.05). Conclusion: The results of this study confirm that the rectus femoris, tibialis anterior, biceps femoris, and gastrocnemius on the surgical side act in an opposite manner to those on the non-surgical side during pedaling in the same section.

• Physical Therapy Rehabilitation Science
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• 제11권4호
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• pp.526-534
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• 2022

Objective: The purpose of this study was to compare muscle activities of stroke patients and healthy participants during bimanual tasks. Design: A cross sectional study. Methods: A total of 25 participants (13 hemiparetic stroke patients and 12 healthy participants) were recruited. The muscle activities using electromyogram (EMG) during bimanual tasks were collected from the following muscles: extensor carpi radialis longus (ECRL), biceps brachii (BB), and triceps brachii (TB). The bimanual tasks included eight tasks consisted of (1) raising the wrists up and down, (2) supinating and pronating the palms, (3) touching the shoulder with fingertips, (4) drawing vertical dot, (5) reaching for a cup and bring it in to drink, (6) drawing a circle outward and (7) inward, and (8) grasping the fingers. The EMG data collected from the muscles of paretic and non-paretic sides of stroke patients and the average from both sides of healthy subjects were normalized and compared after calculating the percentage of maximal isometric voluntary contraction. Results: The ECRL, BB and TB of the paretic side of the stroke patients showed relatively greater muscle activity compared to the non-paretic side as well asaverage of the healthy subject duringall tasks (p<0.05). In addition, the ECRL showed the highest muscle activity during most of the tasks. All of the non-paretic side musclesfrom stroke patients showed higher muscle activity compared to those of healthy subjects. Conclusions: The current study showed that muscle activities of upper extremity varied between paretic and non-paretic sides of stroke patients during bimanual tasks. Interestingly, the non-paretic side muscle activities were also different from those of normal participants.

• 대한의용생체공학회:의공학회지
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• 제44권5호
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• pp.336-345
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• 2023

The present study was designed to evaluate changes in neuromuscular properties and the structural and qualitative characteristics of muscles during submaximal isometric contractions at low-to-relatively vigorous target forces and to determine their influence on force steadiness (FS). Thirteen young adult males performed submaximal isometric knee extensions at 10, 20, 50, and 70% of their maximal voluntary isometric contraction using their non-dominant legs. During submaximal contractions, we recorded force, EMG signals from vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF), and ultrasound images from the distal RF (dRF). Force and EMG standard deviation (SD) and coefficient of variation (CV) values were used to measure FS and EMG steadiness, respectively. Muscle thickness (MT), pennation angle (PA), echo intensity (EI), and texture features were calculated from ultrasound images to assess the structural and qualitative characteristics of the muscle. FS, neuromuscular properties, and texture features showed significant differences across different force levels. Additionally, there were significant differences in EMG_CV among the quadriceps at the 50% and 70% force levels. The results of correlation analysis revealed that FS had a significant relationship with EMG_CV in VM, VL, and RF, as well as with the texture features of dRF. This study's findings demonstrate that EMG steadiness and texture features are influenced by the magnitude of the target force and are closely related to FS, indicating their potential contribution to force output control.

• The Journal of Korean Physical Therapy
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• 제36권2호
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• pp.71-77
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• 2024

Purpose: The prolonged use of digital devices has led to the widespread adoption of poor postures, particularly rounded shoulder posture (RSP), associated with shoulder impingement and pain. This study investigates the effects of neuromuscular electrical stimulation (NMES) on RSP in healthy adults. Methods: Thirty adults with RSP were randomly assigned to NMES only, exercise only, or NMES with exercise groups. NMES was applied to the lower trapezius, which was the target muscle in this study, for a total of 2 weeks, 5 times per week, 20 minutes per session. The exercise program included pectoralis minor stretching, wall-slide exercise, dynamic hug exercise with band, and Brugger stretching for upper body with band, which were performed for a total of 2 weeks, 5 times per week, 20 minutes per session. Outcome measures, including the Supine Method (SM) for posture and surface electromyography (EMG) of the lower trapezius for muscle activity, were assessed before the intervention, after 5 sessions, and after 10 sessions. Results: All the groups showed significant changes in the SM and % maximal voluntary isometric contraction (%MVIC) over time (p<0.05). The NMES group had significantly reduced SM at 1 week, while the exercise and combined groups had reduced SM at 2 weeks (p<0.017). All the groups had increased %MVIC at 2 weeks (p<0.017), with no significant differences observed between groups. Conclusion: NMES alone can be as effective as exercise in improving RSP. NMES combined with exercise also showed positive outcomes, thus offering diverse treatment options for this condition.

• 한국응용과학기술학회지
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• 제36권3호
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• pp.1028-1040
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• 2019

본 연구는 내리막 달리기(downhill running, DR) 후 초음파 영상분석을 이용해 대퇴사두근 무리(quadriceps group, QG) 내 근손상의 국소화 여부를 검증하고, DR 동안 운동 강도가 운동유발성 근손상(exercise-induced muscle damage, EIMD) 및 근육 반향세기 변화에 미치는 영향을 규명하려는 목적으로 수행되었다. 규칙적인 신체활동이 없는 건강한 남성 11명이 무작위 교차설계에 따라 서로 다른 강도[low-intensity DR session($50%HR_{max}$), LDR; high-intensity DR session($70%HR_{max}$), HDR]의 DR 운동을 수행하였다. DR 후 EIMD의 심각성은 혈청크레아틴 키나아제(creatine kinase, CK) 활성 수준 변화와 함께 신경근 기능 지수로서 무릎 신전근의 최대 수의적 등척성 수축(maximal voluntary isometric contraction, MVIC) 및 관절가동범위(range of motion, ROM) 변화를 통해 결정되었다. 회색조 분석을 적용한 근육 반향세기 평가는 DR에 따른 QG 내 국소 근육별(rectus femoris, RF; vastus lateralis, VL; vastus medialis, VM; vastus intermedius, VI) 손상 양상을 탐지하기 위해 활용되었다. 모든 세션에서 혈청 CK 활성 수준과 VL 및 VM의 근통증 정도는 운동 후 24시간째(RF의 경우 각각 LDR 24시간째와 HDR 48시간째) 최대에 이르렀으며, 혈청 CK 수준에서 운동 강도에 따른 유의한 차이(p<.05)가 나타난 반면 근통증에서 세션 간 통계적 차이는 없었다. 무릎 관절을 이용한 MVIC 및 ROM과 같은 신경근 기능 지표 및 VM을 제외한 모든 QG 근육 반향세기는 운동 직후 극적으로 감소 또는 증가 후 72시간까지 점진적 회복 양상을 나타내었다. 그러나 신경근 기능 지표에서 운동 강도에 따른 통계적 차이는 없었으나 RF 및 VL 반향세기에서 세션 내 및 세션 간 유의한 차이(p<.01)를 나타내었다. 본 연구의 결과로 ECC를 함유한 DR 운동 시 운동 강도는 DOMS 및 신경근 기능 지표에 부분적으로 영향을 미칠 가능성이 있으며, 특히 혈청 CK 수준과 함께 RF 및 VL의 근육 반향세기는 운동 강도의 영향을 직접적으로 반영한다는 사실을 알 수 있다. 또한, 현재 연구결과는 DR 동안 ECC를 겪는 QG 내 국소 근육 간 근손상 정도가 다를 수 있으며 초음파 근육 반향세기가 국소 근육의 EIMD 심각성을 차별화할 수 있는 유용한 평가기법임을 뒷받침하고 있다.

• 한국전문물리치료학회지
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• 제6권2호
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• pp.16-31
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• 1999

The purpose of this study was to assess the fatigue in lumbar and abdominal muscles in patients with chronic low back pain compared with normal subjects using spectral analysis with mean power frequency and median power frequency. The experimental group consisted of twenty subjects who had experienced chronic low back pain for over one year after the onset day. A control group consisted of twenty normal subjects with no history of low back pain. All subjects stood in an apparatus to perform sustained contraction in the lumbar and abdominal muscles for 30 seconds with 60% maximal voluntary isometric contraction (MVIC). The resulting electromyographic (EMG) recorded time serial data were transformed into frequency serial data by Fast Fourier Transformation (FFT). The results were as follows: 1) lumbar muscles measured, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group group (p<0.05). In measured two abdominal muscles (inferior rectus abdominis, obliquus externus abdominis) except superior rectus abdominis, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group (p<0.05). 2) In all three (longissimus thoracis, iliocostalis lumborum, multifidus) lumbar muscles measured, the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). In the two (inferior rectus abdominis, obliquus externus abdominis) abdominal muscles measured (superior rectus abdominis not included), the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). These results suggest that in patients with chronic low back pain there is a trend for more fatigue to occur in both lumbar and abdominal muscles than in the normal control group. This would seem to suggest that in treatment programs for patients with chronic low back pain, improvement of endurance in all trunk muscles should be considered.