• 한국운동역학회지
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• 제19권4호
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• pp.655-661
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• 2009

본 연구는 기합소리를 세 가지 유형에 따라 인체내부의 근력의 차이를 비교하기 위해 H-reflex방법과 대퇴직근의 MVIC측정을 하여 추후 충격력과 운동수행에 미치는 효과를 규명하고 최적의 기합소리의 방법을 찾는데 도움을 주고자 설계하였다. 가자미근 H반사는 정강신경이 지나가는 오금에 전기자극을 주어 유발하였고, 표면근전도를 통하여 자료를 수집한 결과 기합 없이 측정한 결과 보다 기합을 지르면서 측정 시 28%증가하였고, 기합을 짧게 지른 직후 측정한 결과 29%가 증가한 것을 볼 수 있었다. 근전도 측정은 오른쪽 하지의 대퇴직근(Rectus femoris)에 표면전극을 부착해 MVIC를 측정한 결과 기합의 유형에 따라 10%와 1%의 증가를 보였다. 이러한 연구 결과에 비추어 기합이 운동신경효율성(H-reflex)과 MVIC의 크기를 변화시키는 것으로 보았을 때 근력증대에 긍정적인 요인을 미치는 것으로 사료되지만 근력증대의 변인 중 기합소리뿐만 아니라 호흡과 관련된 연구, 뇌파와 관련된 연구 등 일반화시킬 수 있는 많은 변인들에 관한 포괄적인 연구가 이루어 져야 할 것으로 사료된다.

• 한국전문물리치료학회지
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• 제13권4호
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• pp.1-9
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• 2006

The purpose of this research was to analyze the effects of the increase of the femoral anteversion angle on the unbalanced quadriceps femoris muscle causing the increase of the valgus force on the knee joints and patellofemoral pain syndrome by comparing with the group that shows the smaller femoral anteversion angle. The method for the research was to compare the femoral muscle's activity while the subjects were maintaining the knee joint flexed isometrically for 10 seconds. The evaluation tool for femoral muscle's activity was QEMG-4 (model LXM 3204). The results were as followings. Firstly, in case of the experimental group, the muscle strength of the vastus lateralis muscle was strong while the rectus femoris and vastus medialis were weak. In these facts, we can see the statistically meaningful difference in vastus medialis muscle activity. Secondly, in the muscle activity analysis for vastus lateralis and medialis of the two groups, we could see the vastus lateralis muscle was strong in anteversion wider for experimental group while the vastus medialis muscle contracted far more stronger in anteversion smaller for control group. From these results, we can see the significant differences in muscle recruitment between the two groups. Above results show that if the anteversion becomes wider, vastus medialis muscle will become seriously weaker, on the other hand, vastus lateralis act stronger.

• 로봇학회논문지
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• 제18권4호
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• pp.385-391
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• 2023

In the elderly population, sarcopenia occurs due to physical aging, leading to movement restrictions and loss of function. This results in dependence on daily activities and limitations in participation, ultimately decreasing the overall quality of life. In this study, we propose an algorithm designed to enable patients with sarcopenia to perform sit-to-stand and stand-to-sit movements seamlessly in their daily lives. The algorithm incorporates a wearable robot for muscle support and includes algorithms for standing and seated muscle strength support. To validate the algorithm's performance, EMG sensors were attached to the Rectus Femoris and Biceps Femoris muscles. The participants underwent two scenarios: one without wearing the device and one with the device providing muscle strength support, performing sit-to-stand and stand-to-sit motions for one minute in each case. The results showed a 16% increase in the EMG peak value of the Rectus Femoris muscle during standing motion (p=0.009). On the right side, there was a roughly 20% decrease (p=0.018) during standing and a 21% decrease (p=0.014) during sitting motion. In the future, we aim to gather additional data to further refine the algorithm. Our goal is to develop an optimal muscle strength support algorithm based on this data, making it applicable for real-life use by patients with sarcopenia.

• 대한통합의학회지
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• 제7권4호
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• pp.33-41
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• 2019

Purpose : The muscle strength of iliopsoas (IL) was measured commonly in sitting position with hip and knee flexed 90°. However, there is no study to determine the muscle strength of IL in various test positions. Therefore, the purpose of this study was to compare the muscle strength of IL and muscle activity of rectus femoris (RF) according to test position and knee flexion angle. Methods : Twenty healthy subjects were participated for this study. The muscle strength of IL and muscle activity of RF were measured by hand-held dynamometer and surface electromyography during maximum voluntary isometric contraction (MVIC) of IL, respectively. The muscle strength of IL and muscle activity of RF was measured in 4 conditions as follows; 1) knee flexion angles 90 ° in supine, 2) 130 ° in supine position, 3) 90 ° in sitting, 4) 130 ° in sitting. Each condition were performed randomly by three repetitions. Results : The muscle strength of the IL was the main effect on the test position and knee flexion angle (p<.05), and the muscle activity of RF was the main effect only on the knee flexion angle (p<.05). There was also no interaction between the factors (p>.05). In supine position, the muscle strength of IL in knee flexion 130 ° was significantly less than that in knee flexion 90 ° (p<.0125). In knee flexion 90 °, the muscle strength of IL in supine position was significantly greater than that in sitting position (p<.0125). The muscle activity of RF in knee flexion 130 ° was significantly less than that in knee flexion 90 ° in supine and sitting positions (p<.0125). Conclusion : When the muscle strength of IL was measured in clinic and sports fields, the supine position with knee flexion 130 ° was recommended to prevent the muscle activation of RF and to maintain the trunk stability.

• The Journal of Korean Physical Therapy
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• 제23권1호
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• pp.7-11
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• 2011

Purpose: Driving is essential to maintain independent living status in modern times. Many patients want to know when they can drive again, but it's only possible if they have the ability to control lower extremity muscles. In this study, we compared the effects of velocity on onset time of lower extremity muscles during driving tasks. Methods: Twelve participants (5 male, 7 female) were enrolled. EMGs were used to test the onset time of lower extremity muscles; tibialis anterior, soleus, rectus femoris. To analyze the data, we used two way ANOVA. Results: According to brake pedaling velocity, there was a significant difference in brake response time (p<0.05). Further, when comparing the lower extremity muscles, there was a significant difference in onset time (p<0.05). The order of muscle recruitment was tibialis anterior, rectus femoris, and soleus for achieving maximal velocity, but the order was rectus femoris, tibialis anterior, soleus for achieving submaximal velocity. Conclusion: Brake pedaling velocity has significant effects on onset time of muscle contractions in the lower extremities. We suggested that a future study needs more subjects and more detailed research such as evaluat-ions of visuo-motor coordination and fine motor dexterity.

• 대한물리의학회지
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• 제4권3호
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• pp.165-174
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• 2009

Purpose：This study was performed for effects of gait training on treadmill and stable surface which influenced on the lower limbs muscular activity needed in gait, plantar foot pressure with hemiplegic patients caused by cerebrovascular accident. Methods：Two groups of adult hemiplegia(n=20) were allocated randomly in this study: treadmill gait training group and control group. The gait training program was provided to experimental groups for 8 weeks (5 times a week). Measurements of pre and post experiment were plantar foot pressure. For measuring muscular activation rectus femoris, biceps femoris, tibialis anterior, gastrocnemius were detected. Results：The results of this study showed that in comparison of pre and post changes of gait training, the treadmill gait training group has noticeable changes than other groups in activity of rectus femoris and tibialis anterior, the control group revealed statistically significant differences in plantar foot pressure Toe2-5, M1, M3, M5, MF area, activity of gastrocnemius. Conclusion：These results mean gait training resulted by treadmill, stable surface provides effective muscle activation and plantar foot pressure with stroke.

• 신경치료
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• 제22권3호
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• pp.31-36
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• 2018

Purpose The purpose of this study was to investigate the effects of contact handorientation response(CHOR) during sit-to-stand(STS) in people with stroke. Methods The subjects of the study were Thirty hemiplegia participated (Rt. hemiplegia/Lt. hemiplegia: 15/15, mean age: $65.82{\pm}8.53$) in this study. The analysis of muscles activation (rectus femoris, biceps femoris, tibialis anterior, gastrocnemius) distribution was conducted by the EMG, and the analysis of foot pressure distribution was conducted by the resistive pressure sensor. Hemiplegic stroke patients were instructed to perform STS three times with the non-affected side hand and affected side hand on the table. Results There was a significant positive correlation between rectus femoris, tibialis anterior muscle activation and affected side hand contact during STS(p<0.05). The STS correlated with the foot pressure in the affected side hand contact(p<0.05). Conclusion AS a result, CHOR during STS is related to muscle activation and the characteristics of foot pressure. This information was observed in the affected side hand contact on the table, suggestion that rehabilitation programs should be implemented.

• PNF and Movement
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• 제17권1호
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• pp.93-101
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• 2019

Purpose: This study aimed to investigate lower extremity muscle activation to the variable weight shift on the affected side of patients with hemiplegia. Methods: Eighteen patients with chronic hemiplegia volunteered to participate in this study. All participants performed three types of weight shift (sideways, forward, and backward) in limits of stability on the affected side. Muscle activation in a paralyzed leg was measured with electromyography on the gluteus medius, tensor fasciae latae, rectus femoris, and biceps femoris; furthermore, the attached area was recommended by SENIAM projects. Each weight shift was performed three times, and then the mean value of the three measurements was analyzed. The data were analyzed by measuring the symmetrically standing position with the reference voluntary contraction (RVC) and was standardized with the percentage of RVC method. Results: No significant difference in lower extremity muscle activation occurred according to the three types of variable weight shift. However, significant differences in lower extremity muscle activation did occur with each weight shift position. In addition, activation increased at the rectus femoris and decreased at the gluteus medius and tensor fasciae latae. Conclusion: Hip abductor muscle strength training and variable weight shifts on the affected side must increase to improve patients'balance and limits of stability.

• The Journal of Korean Physical Therapy
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• 제34권1호
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• pp.45-50
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• 2022

Purpose: The purpose of this study was to compare the spatiotemporal and kinematic gait parameters and muscle activity of the lower extremities between forward walking on sand (FWS) and backward walking on sand (BWS) in normal adults. Methods: This study was conducted on 13 healthy adults. Subjects performed FWS and BWS and the spatiotemporal and kinematic gait parameters of stride time, stride length, velocity, cadence, step length, stance, swing, double support, and hip range of motion (ROM), knee ROM were measured by a wearable inertial measurement unit system. In addition, the muscle activity of the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius (GA) was measured. Results: The stride length, stride velocity, cadence, and step length in the BWS were significantly lower than FWS (p<0.05), and stride time was significantly greater (p<0.05). However, there was no significant difference in the ratio of stance, swing, and double support between the two (p>0.05). The kinematic gait parameters, including hip and knee joint range of motion in BWS, were significantly lower than FWS (p<0.05). The muscle activity of the RF in BWS was significantly higher than FWS (p<0.05), but the muscle activity of the BF, TA, GA did not show any significant differences between the two movements (p>0.05). Conclusion: A strategy to increase stability by changing the gait parameters is used in BWS, and this study confirmed that BWS was a safe and effective movement to increase RF muscle activity without straining the joints. Therefore, BWS can be recommended for effective activation of the RF.

• The Journal of Korean Physical Therapy
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• 제26권2호
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• pp.74-81
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• 2014

Purpose: The purpose of this study is to compare kinematics and kinetics on the knee joint between stair gait with unstable shoes and barefoot in healthy adult women. Methods: Seventeen healthy adult women were recruited for this study. The subjects performed stair ascent and descent with unstable shoes and barefoot. The experiment was repeated three times for each stair gait with unstable shoes and barefoot. Measurement and analysis of the movements of the knee joint were performed using a three-dimensional analysis system. Results: Statistically significant differences in the knee muscle force of semimembranosus, biceps femoris-long head, biceps femoris-short head and sartorius, patellar ligament, medial gastrocnemius, and lateral gastrocnemius were observed between unstable shoes and barefoot gait during stair ascent. Statistically significant differences in the knee muscle force of sartorius, rectus femoris, medial gastrocnemius, and lateral gastrocnemius were observed between unstable shoes and barefoot gait during stair descent. Statistically significant differences in the knee flexor moment of semitendinosus, biceps femoris-long head, biceps femoris-short head, sartorius, rectus femoris, vastus intermedialis, medial gastrocnemius, and lateral gastrocnemius were observed between unstable shoes and barefoot gait during stair ascent. Conclusion: Therefore, wearing unstable shoes during stair gait in daily life is considered to influence knee joint kinematics and kinetics due to the unstable shoes, and thus suggest the possibility that reducing the risks of pain, and knee osteoarthritis, stabilizing the knee joint caused by changes in the loading of the knee joint.