• 한국전문물리치료학회지
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• 제18권2호
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• pp.60-66
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• 2011

Foot posture is important in the development of the musculoskeletal structure in the lower limbs because it can change the mechanical alignment. Although foot orthotics are widely used for the correction of malalignments in the lower extremities, the biomechanical effects of wedges have not yet been cleared. The aim of this study was to investigate whether medial wedges affect the electromyographic (EMG) activity of the knee and hip joints in healthy adults that are performing one leg standing. Seventeen healthy volunteers performed the one leg standing under two foot conditions: A level surface, and a $15^{\circ}$ medial wedge. The subjects' EMG data for the gluteus maximus (Gmax), gluteus medius (Gmed), tensor fasciae latae (TFL), biceps femoris (BF), vastus lateralis (VL), and vastus medialis oblique (VMO) were recorded, along with the surface EMG, and all were analyzed. The EMG activity of the Gmed and TFL had significantly decreased under the medial wedge condition during one leg standing. Further study is needed in order to investigate whether medial wedges influence the EMG activity and kinematic data of the knee and hip joints as well as the ankle joints in adults with flexible flatfoot, while they are performing one leg standing.

• The Journal of Korean Physical Therapy
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• 제22권5호
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• pp.57-61
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• 2010

Purpose: The purpose of this study was to identify the effect of active foot arch support on the muscles of lower extremity electromyographic activity during squat exercise in persons with pronated foot. Methods: The study subjects were 16 persons with pronated foot. They have no history of surgery in lower extremity and trunk and limitation of range of motion or pain when performing squat exercise. Each subject was measured the navicular drop (ND) to determine the pronated foot. And then the subjects were asked to perform three repetitions of a $90^{\circ}$ knee flexion squat in both conditions which are 1) preferred squat and 2) squat with active foot arch support. Results: Paired t-test revealed that squat with active foot arch support produced significantly greater EMG activities in abductor hallucis (p=0.00), proneus longus (p=0.03) and gluteus medius (p=0.04) than preferred squat. But the EMG activities of tibialis anterior, vastus medialis oblique and vastus lateralis were not showed significantly different between the both squat conditions. Conclusion: The findings of this study suggest that active foot arch support during squat increase the activities of lower extremity muscles which are the abductor hallucis, proneus longus and gluteus medius. Also, the abductor hallucis which is one of the planter intrinsic muscle and peroneus longus play a role in support of the foot arch and active foot arch support induced the increase of the activity of gluteus medius. Therefore active foot arch support can change the lower extremity biomechanics as well as passive foot support such as foot orthotics and taping.

• 대한물리의학회지
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• 제8권4호
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• pp.647-653
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• 2013

PURPOSE: The purpose of this study was to compare the lower extremities muscle activation between squatting exercise with gym ball and wall for improving muscle strengthening in lower extremities. METHODS: Participants were 21 university students (males 10, females 11) who didn't have any problem with orthopedic surgery. Participants performed squatting exercise with gym ball and wall. Squatting exercise with gym ball were performed using by gym ball behind back, and the gym ball were fixed in back and wall. We asked participants to push back the gym ball slightly to prevent fall of ball. Wall squatting exercise, we ask participants to contact their back in wall slightly in order to prevent trunk flexion during performed squatting exercise. Each squatting exercise had performed until knee joint were flexed at 60 degree, and maintained five seconds. We collected data from E.M.G of Biceps femoris, Gastrocnemius, Vastus medialis and lateralis, Tibialis anterior of lower extremity in isometric phase of knee joint angle 60 degree of each squatting exercise. We analysed data using by ANOVA and independent t-test of SPSS PC ver.20.0 in order to compare the muscle activation between squatting exercise with gym ball and wall. RESULT: All of lower extremities muscle activation showed more higher value in squatting exercise with gym ball than squatting exercise with wall, especially there was significantly difference of muscle activation in vastus medialis, tibialis anterior between squatting exercise with gymball and with wall. CONCLUSION: On comprehensively considering the results of the present study, we suggested that squatting exercise with gym ball was more effective method improving lower extremity muscle strengthening.

• The Journal of Korean Physical Therapy
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• 제26권5호
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• pp.290-295
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• 2014

Purpose: The purpose of this study was to assess the effects of robo-horseback riding with changes of pelvic tilting and speeds on muscle activities of trunk and lower limb in healthy adults. Methods: Thirty healthy adults were recruited for this study. Subjects performed robo-horseback riding at three pelvic postures (anterior tilting pelvic posture: AP, neutral pelvic posture: NP, posterior pelvic posture: PP) and different speeds (moderate and fast speed). Muscle activities were recorded from the trunk muscles (rectus abdominis [RA], T2 paraspinalis [T2 PS], L2 paraspinalis [L2 PS]) and lower limb muscles (rectus femoris [RF], vastus medialis [VM], vastus lateralis [VL], biceps femoris [BF], gastrucnemius [GCM]). Results: Significantly higher RA activities were observed under the PP condition than under the AP and NP conditions at both speeds. Significantly higher L2 PS activities were observed under the AP condition than under the PP and NP conditions at both speeds. Significantly higher T2 PS activities were observed under the AP condition than under the PP and NP conditions at fast speed. However, the muscle activities of the VM and GCM did not show significant changes with changes in pelvic posture at both speeds. All muscle activities were significantly higher under the fast speed than under the moderate speed in three pelvic postures. Conclusion: There were significant differences in the changes of pelvic tilting on muscle activities of trunk and lower limb were observed in healthy adults. NP condition can be introduced the most efficienct posture for muscle activities of trunk and lower limb in robo-horseback riding.

• 대한물리의학회지
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• 제14권4호
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• pp.55-62
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• 2019

PURPOSE: This study examined the muscle activity while stepping over obstacles with various heights and widths to provide basic data for training and preventing falls. METHODS: Fifteen normal young adults (seven males and eight females) were recruited. The participants walked on a 5m walkway with six obstacles. The heights of obstacles were 0%, 10%, and 40% of the subject's leg length, and the width of the obstacles was 7cm and 14cm. The participants traversed the course twice per obstacle. The muscle activities of the soleus, tibialis anterior (TA), vastus medialis (VM), and vastus lateralis (VL) were measured using surface electromyography. A Mann-Whitney test and Kruskal-Wallis test were used to examine the differences between obstacles. RESULTS: The muscle activities of the VL and the soleus of the stance leg and lead leg after crossing over the obstacles increased with increasing width, and there were significant differences in muscle activities between obstacle width (p<.05) except for the muscle activity of TA of the stance leg after crossing over the obstacles. A significant difference in muscle activities was observed according to the height of the obstacles with 14 cm (p<.05) except for the muscle activity of the VL, soleus of the leading leg, and TA of the stance leg CONCLUSION: The role of the VL and Soleus increased with increasing obstacle width, and the overall muscle activities of the lower extremities increased with increasing obstacle height. These results can be used to suggest a program to prevent falls.

• 대한의용생체공학회:의공학회지
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• 제28권5호
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• pp.636-646
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• 2007

Adequate postural control depends on the spatial and temporal integration of vestibular, visual, and somatosensory information. Especially, the musculoskeletal function is essential to maintain the postural control. The experimental studies was performed on the muscular activities in the lower extremities during maintaining and moving exercises on an unstable platform with Magneto Rheological(MR) dampers. The unstable platform of the developed system was controlled by electric currents to the MR dampers. A subject executed the maintaining and moving exercises which are presented through the display monitor. The electromyographies of the eight muscles in lower extremities were recorded and analyzed in the time and the frequency domain: the muscles of interest were rectus femoris(RF), biceps femoris(BF), tensor fasciae latae(TFL), vastus lateralis(VL), vastus medialis(VM), gastrocnemius(Ga), tibialis anterior(TA), Soleus(So). The experimental results showed that the muscular activities differed in the four moving exercises and the nine maintaining exercises. For the anterior-posterior pattern, the TA showed highest activities; for the left-right pattern, the TFL; for the 45, $-45^{\circ}$ pattern, the TFL and TA. Also, the rate of the increase in the muscular activities were affected by the condition of the unstable platform with MR dampers for the maintaining and moving exercises. The experimental results suggest that the choice of different maintaining and moving exercises could selectively train different muscles in various intensity. Futhermore, the findings suggested that the training using this system can improve the ability of postural control.

• 한국항행학회논문지
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• 제15권6호
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• pp.1152-1162
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• 2011

본 논문에서는 등장성 수축(isotonic contraction)시 연령에 따른 변화의 추이 등을 알아보기 위해 일상생활에서 주로 사용하는 대퇴사두근의 근 활성도(muscle activity)와 근 피로도(muscle fatigue) 해석에 관한 연구를 하였다. 실험은 남자 20대와 50대 각 10명씩을 대상으로 무릎 확장운동으로 각 피 실험자가 할 수 있는 최대 부하(1RM)를 측정한 다음 그 부하의 20-90%부하를 차례로 증가 시키면서 대퇴사두근(Quadriceps Femoris :QF)은 내측광근(vastus medialis : VM), 대퇴직근(rectus femoris : RF), 외측광근(vastus lateralis : VL) 등을 각각 근전도 신호를 추출하고, 수축, 이완모드에서 각속도를 측정하였다. 20대와 50대의 속도를 비교분석한 결과 대퇴사두근의 20대 근육에서는 (p < 0.89)로 50대에서는 (p < 0.70)로 유의차가 없는 것으로 나타났다. 생체 동역학 연구와 체육 분야의 선수 훈련방법, 산업분야에서 상해방지와 근육부상방지, 재활의약분야의 부상치료 등에 응용할 수 있을 것으로 사료된다.

• 수산해양교육연구
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• 제27권1호
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• pp.63-73
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• 2015

The purpose of this study was to examine EMG activities and VMO/VL ratio of the vastus medialis oblique, and vastus lateralis during step up exercise according to ankle and knee positions in soccer players with patellofemoral pain syndrome. Methods: Subject(patellofemoral pain syndrome, PFPS: n=8 and without PFPS, non PFPS; NPFPS: n=8) perfomed step up exercise at each knee and ankle position(knee flexion $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$, ankle internal rotation $30^{\circ}$, neutral, and external rotation $30^{\circ}$) while EMG activity was collected. The EMG signals were expressed by the % maximal voluntary isometric Contraction(%MVIC) values. Statistical analysis consisted of two way repeated measures analysis of variance with post hoc analysis. Results: Main results were as follows: 1) EMG of VMO, and VL was tend to be lower in PFPS compared to NPFPS. 2) EMG of VMO and VL with knee flexrion $60^{\circ}$ was significantly higher the results with knee flexion $30^{\circ}$, and $90^{\circ}$. VMO and VL with ankle external rotation $30^{\circ}$ was significantly higher the results with internal rotation $30^{\circ}$ and neutral position. Conclusion: Considering the EMG activity was reduced due to the to the PFPS and that performing step up with knee flexion $60^{\circ}$ with ankle external rotation $30^{\circ}$ position may provide the most effective condition for patients with patellofemoral pain syndrome.

• 국제물리치료학회지
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• 제4권2호
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• pp.595-599
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• 2013

The purpose of this study is to identify the bridge exercise posture for the efficient exercise by comparing the muscle activity of the lower limbs according to the changes in muscle length because of knee angle in bridge exercise. The subjects of this study were 9 randomly selected males in their 20s living in D city from those who satisfied inclusion criteria. The measured muscles were Vastus medialis oblique, Vastus lateralis, Semitendinosus, Biceps femoris, Gluteus maximus, Gluteus medius, Tensor faciae latae, and Adductor longus. Data were analyzed through paired comparison test. In the result, ST, BF, and TFL muscle activities were high when knee joint flexion angle was $90^{\circ}$ Although in most cases higher muscle activity was shown at $90^{\circ}$ than $60^{\circ}$ there was no statistical significance. Interestingly, it was lower at $90^{\circ}$ than $60^{\circ}$ in VL. In ST, BF, and TFL, it was significantly higher at $90^{\circ}$ than $60^{\circ}$ (p<.05). Conclusively, knee angles in bridge exercise may affect the muscle activity, and in particular when the activity of two joint muscles such as semimenbranosus muscle, biceps femoris muscle, and tensor fasciae latae muscle increase as the angle gets higher. Therefore, it is considered that this study will provide helpful tips to develop muscular strength enforcement program for the patients with damages in the lower limbs through bridge exercise in clinical situations.

• 대한정형도수물리치료학회지
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• 제19권2호
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• pp.61-66
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• 2013

Background: This study tried to identify the bridge exercise posture for efficient exercise application by comparing muscle activity of buttocks and thighs according to internal-external rotation and pronation & supination in bridge exercise. Method: Nine males in their 20s living in D city were randomly selected as subjects. Muscles such as vastus medialis oblique (VMO), vastus lateralis (VL), semitendinosus (ST), biceps femoris (BF), gluteus maximus (GMAX), gluteus medius (GMED), tensor fasciae latae(TFL), and adductor longus (ADL) were measured using eight channel surface electromyogram (MyoSystem 1400A, Noraxon, USA) to measure muscle activity. Statistics process was performed through paired t test. Results: In the changes in electromyogram signals according to internal-external rotations according to internal-external rotation of shinbones, in most cases muscle activity was higher in external rotation than in internal rotation, but there was no statistical significance (p>.05). In particular, it was lower in TFL and ADL. There was no statistical significance in the comparison between two groups (p>.05). In the changes in electromyogram signals according to internal-external rotations according to pronation & supination of thighs, GMED showed significantly higher value in supination than in pronation (p>.05), and in ADL pronation is significantly higher than supination (p<.05). Conclusion: In internal-external rotation of shinbone and pronation & supination of thighs in bridge exercise, changes in muscle length can make effects on muscle activity of buttocks and thighs. Therefore, muscle strength enforcement program on buttocks and thighs through bridge exercise can make effects on patients with lower limb functional damages in clinical situations.