• The Journal of Korean Physical Therapy
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• v.31 no.6
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• pp.363-367
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• 2019

Purpose: This study was to investigate the effect of instability on the activation of lower limb muscles during lunge exercise. Methods: The study subjects were healthy twenties and were selected to have no orthopedic or neurological diseases. 1) Flat lunge exercise (Lunge 1, 2) Lunge exercise on TOGU (Lunge 2, 3) Holding the olympic bar and moving the lunge on TOGU (Lunge 3, 4) Holding the Surge and moving the lunge on TOGU (Lunge 4). Through the above four actions, we can see how the top-down instability influences the lower limb unlike the Bottom-up instability. EMG attachment sites were gluteus medius, vastus medialis, gastrocnemius, tibialis anterior. Results: These result suggest that exercise using Lunge 4 activity was the highest in muscle activity compared to other exercises, but vastus medialis showed the highest muscle activity in Lunge 2 exercise(p<0.05). Conclusion: This study showed the muscular activity of the lower extremities according to the lunge exercise using the instability tools.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.2
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• pp.43-50
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• 2017

Purpose : There is no validated method for measuring the toe flexor strength that can isolate the intrinsic muscles of the foot from the extrinsic muscles. This study compared the hallux flexion force (HFF) and muscle activity in the foot and ankle according to ankle position [plantarflexion (PF), neutral, and dorsiflexion (DF)]. Method : The study enrolled 17 subjects. In the sitting position, the HFF and activities of the abductor hallucis (AbdH), tibialis anterior (TA), and gastrocnemius (GCM) muscles were measured using a digital dynamometer and a wireless electromyography system, respectively. Subjects were instructed to flex the great toe maximally in three different ankle positions. Three 5-second trials were performed to measure the HFF and muscle activities in each condition. Repeated-measures ANOVA was used to compare the variables and paired t-tests with the Bonferroni correction were used for post-hoc pair-wise comparisons. The significance level was set at .016. Result : The HFF in DF was significantly greater than in any other ankle position (p<.01). The TA activity was greatest in ankle DF and that of the GCM was greatest in PF (both p<.01). However, there was no significant difference in AbdH activity according to ankle position. Conclusion : These results suggest that selective strength measurement of the foot intrinsic muscles in HFF should be performed with the ankle in the neutral position.

• Journal of International Academy of Physical Therapy Research
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• v.7 no.2
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• pp.1037-1040
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• 2016

This study aims to investigate the effects of ankle foot orthosis(AFO) on the activities of tibialis anterior(TA), soleus(Sol), rectus femoris(RF) and biceps femoris(BF) during stairs descending. The activities of TA, Sol, RF and BF were initially measured while descending 4 stairs without using AFO. The activities of the same muscles were then measured again while descending 4 stairs while using AFO. Wilcoxon signed-rank tests were used to analyze the results in order to examine the differences between the with using AFO and without using AFO. Although the activities of TA, Sol and RF were relatively lower while using AFO than without using AFO, only the differences in Sol and RF activities were significant(p<0.05). The activity of BF was relatively higher while using AFO compared to the activity of BF observed without using AFO. However, difference was not significant(p>0.05). Conclusion of this study was observed since AFO's ground reaction force absorption during stairs descending reduced the need to use So and RF that is related to shock absorption. BF activity was increased with AFO than without during standing forward to correct the trunk stability.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.2
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• pp.95-98
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• 2015

PURPOSE: This study was conducted to devise a method of preventing water infiltration into the surface electrodes during EMG measurements underwater and on the ground and to check the reliability of Electromyography (EMG) measurements when underwater. METHODS: Six healthy adults were selected as subjects in this study. The measurements in this study were conducted in pool dedicated to underwater exercise and physical therapy room in the hospital building. An MP150 (Biopac Systems, US, 2010) and a BioNomadix 2-channel wireless EMG transmitter (Biopac Systems, US, 2012) was used to examine the muscle activity of rectus femoris, biceps femoris, tibialis anterior, gastrocnemius of dominant side. The subjects repeated circulation tasks on the ground for more than 10 min for enough surface electrode attachment movement. After a 15-min break, subjects performed the circulation task underwater(water depth 1.1m, water temperature $33.5^{\circ}C$, air temperature $27^{\circ}C$), as on the ground, for more than 10 min, and the MVIC of each muscle was measured again. SPSS v20.0 was used for all statistical computations. RESULTS: The maximum voluntary isometric contraction (MVIC) values between the underwater and on the ground measurements showed no significant differences in all four muscles and showed a high intraclass correlation coefficient (ICC) of >0.80. CONCLUSION: We determined that EMG measurements obtained underwater could be used with high reliability, comparable to ground measurements.

• PNF and Movement
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• v.10 no.4
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• pp.25-31
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• 2012

Purpose : The purpose of present study was to investigate the effects of proprioceptive neuromuscular facilitation (PNF) lifting on contralateral leg muscle activities in a seated position. Methods : Twenty healthy subjects were recruited for this study. Lifting was performed from each of the three position. An surface electromyogram (EMG) was used to record the EMG activities from vastus medialis (VM), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius medialis (GM) in contralateral leg muscle. The data were analyzed using a repeated measures of one-way analysis of variance (ANOVA) with post-hoc Bonferroni's correction to determine the statistical significance. Results : The results of this study were summarized as follows: In comparison to the start position, percentage maximal voluntary isometric contraction (%MVIC) values of the VM, TA and GM demonstrated a significantly higher activities in the end position(p<.05). Conclusion : The result shows that contralateral leg muscles activities significantly more increase in the end position when PNF lifting was applied. Therefore, this study will be used to prove effect of indirect approach for the stability and strengthening in patients with leg impairments.

• Journal of Biomedical Engineering Research
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• v.28 no.5
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• pp.590-600
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• 2007

We performed experimental studies on the muscle activities in the lower limbs for the different movement patterns on an unstable platform. A training system for postural control using an unstable platform that we previously developed was applied for the experiments. This unstable platform provides 360 degrees of movement allowing for training of posture in various directions and provides simultaneous excitations to visual sensory, somatic sensation and vestibular organs. Compare with the stable platform, keeping body balance on the unstable platform requests more effective sensation from vision, vestibular sense and somatic sense. Especially, the somatosensory inputs from the muscle proprioceptors and muscle force are crucial. To study the muscle activities for the different movement patterns and find the best training method for improving the ability of postural control through training and improving the lower extremity muscular strength, fifteen young healthy participants went through trainings and experiments. The participants were instructed to move the center of pressure following the appointed movement pattern while standing on the unstable platform. The electromyographies of the muscles in the lower limbs were recorded and analyzed in the time and the frequency domain. Our experimental results showed the significant differences in muscle activities for the different movement patterns. Especially, the spectral energy of electromyography signals in muscle for the movement pattern in anterior-posterior direction was significantly higher than those occurred in the other patterns. The muscles in the lower leg, especially tibialis anterior and gastrocnemius were more activated compared to the others for controlling the balance of body on the unstable platform. The experimental results suggest that, through the choice of different movement pattern, the training for lower extremity strength could be performed on specific muscles in different intensity. And, the ability of postural control could be improved by the training for lower extremity strength.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4598-4603
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• 2012

The purpose of this study is to compare and evaluate the balance and muscle activity after having performed balance exercise at different ground conditions. The subjects were divided into 3 groups; Sand Group(SG)(N=30) and Balance Form group(BFG)(N=30), Hard Ground Group(HGG)(N=30). The period of intervention was for six weeks. EMG for Tibialis anterior(TA), Soleus(So), Biceps femoris(BF) muscle activity, Air-balance system 3D were used as evaluation tools for this study. the change of balance ability and TA, So muscle activity was greater in the SG, BFG than HGG which may imply that sand can be used for the balance exercise like any other ground.

• Journal of the Korean Society of Physical Medicine
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• v.3 no.4
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• pp.215-224
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• 2008

Purpose : The purpose of this study was to evaluate the effects of the Hahoe mask dance on the gait and muscle activity in the elderly who lived at a elderly welfare facility. Methods : Dancing group was consisted of 20 subjects(over 70 years). The time of measurement was assigned in pre measurement, after 1 month, after 2 months. Subjects was received the Hahoe mask dance for three times a week during 8 weeks. The control group was consisted of 20 the elderly (similar age) who didn't received dancing. Assessment of gait function included the gait velocity, step time, stride, step length, it was analyzed in activity for 4 muscles (rectus femoris, biceps femoris, tibialis anterior, and lateral gastrocnemius). Results : Activities for muscles of control group was decreased in rectus femoris, bieps femoris, however, those of experimental group was increased significantly(p<.05). While control group showed decrease in the gait velocity per second (p<.05), experimental group showed statistically significant increase(p<.05). Control group had a significant long time than that of control group in gait time of right and left foot(p<.05). Control group was a little longer than control group in stride time of right and left foot(p<.05). Step length for control group was shorter than that for experimental group both foots(p<.05). Conclusion : In conclusion, this study confirmed that activities for 4 muscles by EMG have showed significant increases, so we will use a programme of muscle improvement in elderly community welfare faculty. We recommend that further research should explore the degree of muscle activity by larger sample sizes and longer follow-up periods.

• Korean Journal of Applied Biomechanics
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• v.27 no.1
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• pp.35-43
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• 2017

Objective: The purpose of this study was to determine how gaze angle affects muscle activity and kinematic variables during treadmill walking and to offer scientific information for effective and safe treadmill training environment. Method: Ten male subjects who have no musculoskeletal disorder were recruited. Eight pairs of surface electrodes were attached to the right side of the body to monitor the upper trapezius (UT), rectus abdominis (RA), erector spinae (ES), rectus femoris (RF), bicep femoris (BF), tibialis anterior (TA), medialis gastrocnemius (MG), and lateral gastrocnemius (LG). Two digital camcorders were used to obtain 3-D kinematics of the lower extremity. Each subject walked on a treadmill with a TV monitor at three different heights (eye level; EL, 20% above eye level; AE, 20% below eye level; BE) at speed of 5.0 km/h. For each trial being analyzed, five critical instants and four phases were identified from the video recording. For each dependent variable, one-way ANOVA with repeated measures was used to determine whether there were significant differences among three different conditions (p<.05). When a significant difference was found, post hoc analyses were performed using the contrast procedure. Results: This study found that average and peak IEMG values for EL were generally smaller than the corresponding values for AE and BE but the differences were not statically significant. There were also no significant changes in kinematic variables among three different gaze angles. Conclusion: Based on the results of this study, gaze angle does not affect muscle activity and kinematic variables during treadmill walking. However, it is interesting to note that walking with BE may increase the muscle activity of the trapezius and the lower extremity. Moreover, it may hinder proper dorsiflexion during landing phase. Thus, it seems to reasonable to suggest that inappropriate gaze angle should be avoided in treadmill walking. It is obvious that increased walking speed may cause a significant changes in biomechanical parameters used in this study. It is recommended that future studies be conducted which are similar to the present investigation but using different walking speed.

• Korean Journal of Applied Biomechanics
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• v.20 no.2
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• pp.221-230
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• 2010

The purpose of this study was to analyze biomechanical factors of trail running shoes applied to korean shoe-lasts. 10 healthy male subjects with an average age of 37.2 years(SD=8.28), weight of 69.6 kg(SD=10.56) and a height of 171 cm(SD=4.93) were recruited for this study. Ten males walked on a treadmill wearing four different shoes. Foot pressure data was collected using a Pedar-X mobile system(Novel Gmbh., Germany) operating at the 1000 Hz. Surface EMG signals for tibialis anterior, gastrocnemius, vastus lateralis and biceps femoris were acquired at 1000 Hz using Noraxon TeleMyo DTS system(Noraxon Inc., USA). Foot pressure and leg muscle fatigue were measured and calculated during walking. The results are as follows: After walking 60 minutes, Type A showed a lower MPF. MPF values were significantly different from each muscle(p<.05). Therefore, Type A shoe might decrease muscle fatigue in the legs while walking. In addition, Type It showed that Type A shoe has the highest contact area and the lowest maximum pressure. As a result of the analysis, Trail running shoes will use a new design to reduce muscle fatigue and are expected to increase comfort and fitting.