• 한국운동역학회지
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• 제22권3호
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• pp.349-356
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• 2012

This study aimed to assess the effects of progressive lumbar stability exercises and lumbar stability exercises on changes in the transversus abdominis muscle thickness and lower extremity muscle fatigue index in soccer players. Ten subjects were assigned to undergo training in each of the 2 groups, namely, the progressive lumbar stability exercise group and lumbar stability exercise group. Each intervention session lasted for 30 min, and 4 sessions were conducted in a week for 6 weeks for soccer players of S. University in Jeonnam, Korea. Changes in the transversus abdominis muscle thickness and lower extremity muscle fatigue index were measured using ultrasound and surface electromyogram. The results of the ultrasound measurement for the transversus abdominis muscle thickness indicated that progressive lumbar stability exercises were more effective than lumbar stability exercises. The results of the lower extremity muscle fatigue index measurements using surface electromyogram indicated that the fatigue index decreased in the progressive lumbar stability exercise group. Progressive lumbar stability exercise is believed to have put more workload during the shaking of the limbs, leading to increased stability and increased efficiency of the lower extremity muscle, thereby decreasing the fatigue index. Therefore, progressive lumbar stability exercises can be an effective measure for preventing injuries and improving the game performance of sports players by increasing the transversus abdominis muscle thickness and decreasing the lower extremity muscle fatigue index.

• 대한물리치료과학회지
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• 제24권2호
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• pp.27-35
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• 2017

Purpose: This study aimed to investigate the effect of shoes sole form on fatigue of lower extremity during treadmill gait. Method: Thirty healthy young adults (15 males and 15 females) were recruited. They performed treadmill gait in two different conditions: double sole(DS) and flat sole(FS). Result: lower extremity fatigue were signficantly decreased in double sole condition(p<.05). Conclusion: These findings suggest that double sole contributes to reduction of lower extremity muscle fatigue.

• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.323-330
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• 2002

This study purposes at applying knee joint taping to preventing muscle fatigue. Twenty six subjects between the ages of 20s and 30s were randomly sampled among healthy males, with an average age of 26yr(range, 22 to 31yr). None of the subjects had a recent or remote history of significant lower extremity injury, No subjects had a history of central nervous system equilibrium problems. To develop muscle fatigue, Isokinetic exercise, which is a repetition of flexion and extension knee joint to $180^{\circ}$/sec, was performed 50 times per person. During the exercise, change of proprioception were measured by applying taping on both knee joints. Analysis has carried out by means of one-way ANOVA with repeated measures and independent t-test at the significance level of $\alpha$=0.05 to detect statistic significance. The results of this study were as follows: First, it was found that the generation of lower extremity muscle fatigue significant affects on proprioception (p < 0.05). Second, the application of taping to knee joint after the generation of lower extremity muscle fatigue significant affect proprioception (p < 0.05). Third, while continual exercise after the generation of muscle fatigue, taping group was significant differences in proprioceptive loss than non-taping group(p < 0.05).

• 대한물리치료과학회지
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• 제27권1호
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• pp.43-50
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• 2020

Background: This study was to investigate the immediate effects of kinesio taping (KT) of quadriceps on muscle strengthening and balance ability. Design: Randomized controlled trial and conducted as a single-blind. Methods: Twenty-four subjects participated in this study. They were randomly allocated two groups: kinesio taping group (KT group, n=12), placebo kinesio taping group (PKT group, n=12). The participants were tested with lower extremity muscle strengthening and balance ability pre-post intervention. Results: After training, the change values of the lower extremity muscle strengthening and balance ability in the KT group were significantly greater than the PKT group (p<0.05). Conclusion: The results indicated that kinesio taping were effective the promoting the lower extremity muscle strengthening and balance ability.

• 한국전문물리치료학회지
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• 제15권1호
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• pp.38-45
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• 2008

This study investigated gait characteristics, kinematics, and kinetics in the lower extremities between two different shoe conditions (high heeled shoes (7 cm), and high heeled shoes with a total contact insert (TCI)) after lower extremity muscle fatigue. Although TCI shave been applied in high heeled shoes to increase comfort and to decrease foot pressure, no study has attempted to identify the effects of TCI in fatigue conditions. The purpose of this study was to determine the effects of walking in high heeled shoes with TCI after lower extremity muscle fatigue was induced. This study was carried out in a motion analysis laboratory at Hanseo University. A volunteer sample of 14 healthy female subjects participated. All in fatigue conditions, the subjects were divided into two groups. The muscle fatigue was induced by 40 voluntary dorsi- and plantar-flexion exercises and 40 heel-rise exercises of the dominant foot. Surface electromyography was used to confirm the localized muscle fatigue using power spectral analysis of three muscles (tibialis anterior, gastrocnemius medialis and lateralis). The results were as follows: (1) In muscle fatigue conditions, the use of TCI decreased the peak flexion angle of the hip joint significantly in the early stance phase (p<.05) and increased the peak hip flexion moment in the terminal stance phase (p<.05). (2) In muscle fatigue conditions, the application of TCI also increased peak hip power generation in the early stance phase and peak hip power absorption in the terminal stance phase (p<.05). (3) In muscle fatigue conditions, the use of TCI reduced the impact force significantly and increased the secondary peak vertical GRF. These findings suggest that the TCI may provide beneficial effects when muscle fatigue occurs for a high heeled shoe gait. Future research employing the patient population and various types of TCI materials are required to clarify the effects of TCI.

• 대한물리의학회지
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• 제14권3호
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• pp.127-133
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• 2019

PURPOSE: The aim of this study was to obtain detailed and quantified data concerning the effects of plantarflexor fatigue induced to the non-paretic side on muscle activities of the bilateral lower extremities during walking in chronic stroke patients. METHODS: In this study, chronic stroke patients were evaluated for six months after the onset of stroke. To induce the non-paretic plantarflexor fatigue, 20 chronic stroke patients were asked to perform their given fatigue affecting assignments, which were presented in a forced contraction fatigue test method, until the range of motion of the plantarflexor was reduced to less than 50%. The muscle activities of the rectus femoris, tibialis anterior and gastrocnemius in the paretic and non-paretic lower extremities were measured using a wireless surface EMG before and after muscle fatigue induction. RESULTS: The findings showed that after plantarflexor fatigue was induced on the non-paretic side, a significant decrease in muscle activities of the rectus femoris on the paretic side was noted (p<.05). The muscle activities of the tibialis anterior and gastrocnemius were also observed to decrease, but, these results were not statistically significant (p>.05). In the non-paretic side, there was a significantly decrease in the muscle activities of the rectus femoris, tibialis anterior, and gastrocnemius (p<.05). CONCLUSION: These finding suggest that the muscle fatigue of the non-paretic plantarflexor affects not only the muscle activity of the ipsilateral lower extremity but also the muscles activity of the contralateral lower extremity. This highlights the necessity of performing exercise or training programs that do not cause muscle fatigue in clinical aspects.

• Safety and Health at Work
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• 제10권3호
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• pp.321-326
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• 2019

Background: Performing cognitive tasks and muscular fatigue have been shown to increase muscle activity of the lower extremity during quiet standing. A common intervention to reduce muscular fatigue is to provide a softer shoe-surface interface. However, little is known regarding how muscle activity is affected by softer shoe-surface interfaces during static standing. The purpose of this study was to assess lower extremity muscular activity during erect standing on three different standing surfaces, before and after an acute workload and during cognitive tasks. Methods: Surface electromyography was collected on ankle dorsiflexors and plantarflexors, and knee flexors and extensors of fifteen male participants. Dependent electromyography variables of mean, peak, root mean square, and cocontraction index were calculated and analyzed with a $2{\times}2{\times}3$ within-subject repeated measures analysis of variance. Results: Pre-workload muscle activity did not differ between surfaces and cognitive task conditions. However, greater muscle activity during post-workload balance assessment was found, specifically during the cognitive task. Cognitive task errors did not differ between surface and workload. Conclusions: The cognitive task after workload increased lower extremity muscular activity compared to quite standing, irrespective of the surface condition, suggesting an increased demand was placed on the postural control system as the result of both fatigue and cognitive task.

• 한국운동역학회지
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• 제18권2호
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• pp.115-124
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• 2008

본 연구는 행군 시 발보장구 착용이 하지 근육 활동에 미치는 영향을 알아보는데 목적이 있다. 과회내족과 정상족을 선정하여 트레드밀에서 4.5km/h의 속도로 걷게 하였고 이때 근전도기를 이용하여 하지근육의 근육신호를 수집, 분석하였다. 수집한 데이터를 평균적분근전도와 스펙트럼 분석을 통해 근활성도와 피로도를 알아보았고 SPSS 12.0을 이용하여 통계분석하였다. 실험 결과는 과회내족이 정상족보다 행군 시 근 활성이 큰 것으로 나타났고, 보장구 착용 시 근 활성과 피로도가 줄어드는 경향을 나타냈다. 특히 전경골근과 장비골근의 근육활성 감소와 피로도 감소가 통계적으로 유의한 차이를 나타냈다. 결과적으로 과회내족은 장시간 행군 시 발보장구 착용이 피로도 감소에 효과적이며 이는 잠재적인 하지 근골격계 상해 예방에 도움이 될 것으로 사료된다.

• 산업경영시스템학회지
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• 제23권60호
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• pp.37-46
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• 2000

A biomechanical model of lower extremity in seated postures was developed to assess muscular activities of lower extremity involved in a variety of foot pedal operations. The model incorporated four rigid body segments with the twenty-four muscles to represent lower extremity This study deals with quasi-static movement to investigate dynamic movement effect in seated foot operation. It is found that optimization method which has been used for modeling the articulated body segments does not predict the forces generated from biarticular muscles and antagonistic muscles reasonably. So, the revised nonlinear optimization scheme was employed to consider the synergistic effects of biarticular muscles and the antagonistic muscle effects from the stabilization of the joint. For the model validation, three male subjects performed the experiments in which EMG activities of the nine lower extremity muscles were measured. Predicted muscle forces were compared with the corresponding EMG amplitudes and it showed no statistical difference. For the selection of optimal seated posture, a physiological meaningful criterion was developed for muscular load sharing developed. For exertion levels, the transition point of type F motor unit of each muscle is inferred by analyzing the electromyogram at the seated postures. Also, for predetermined seated foot operations exertion levels, the recruitment pattern is identified in the continuous exertion, by analyzing the electromyogram changes due to the accumulated muscle fatigue.

• 대한산업공학회지
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• 제24권2호
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• pp.261-278
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• 1998

The paper represented the lower extremity muscle model as four rigid-body segments: trunk, shank, and foot. We transformed their tibial data into our shank data by rotating their tibial X and Y axes by 5.483 degrees, so the revised coordinate data used to translating the origin of their tibial reference frame to our shank reference frame. According to weight of subject, physiological cross-setional area(PCSA) of each lower extremity muscle was calculated by scaling those data by Brand. The objectives of this paper are to investigate the variations of the recruitment patterns of the lower extremity muscles, and to analyze the changes of the role assigned to each muscle during the seated foot operation. For exertion levels, the transition point of type F motor unit of each muscle is inferred by analyzing the electromyogram at the seated postures. Also, for predetermined seated foot operations exertion levels, the recruitment pattern and the changes of the role assigned are identified in the continuous exertion, by analyzing the electromyogram changes due to the accumulated muscle fatigue. This study can be used to design and to assess the pedals and foot-related equipments design.