• Physical Therapy Korea
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• v.15 no.1
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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.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.1
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• pp.47-57
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• 2016

In this paper, we measured human body signals in order to verify a active harness system that we developed for gait and balance training. The experimental procedure was validated by tests with 20 healthy male subjects. They conducted motions of Activities of Daily Living(ADL)(Normal Walking, Stand-to-Sit, Sit-to-Stand, Stair Walking Up, and Stair Walking Down) according to body weight support rates (0%, 30%, 50% of subjects' body weight). The effectiveness of the active harness system is verified by using the results of foot pressure distribution. In normal walking, the decrease of fore-foot pressure, lateral soleus muscle and biceps femoris muscle were remarkable. The result of stand-to-sit results motion indicated that the rear-foot pressure and tibialis anterior muscle activities exceptionally decreased according to body weight support. The stair walking down show the marked drop of fore-foot pressure and rectus femoris muscle activities. The sit-to-stand and stair walking up activities were inadequate about the effect of body weight support because the velocity of body weight support system was slower than male's activity.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.227-235
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• 2009

The purpose of this study was to analyze differences of 45minutes up-hill walking depending on hiking poles and steady walking time. Seven healthy men volunteered for this experiment. Each of them performed up-hill walking with hiking poles and without hiking poles at speed of 3.5km/h during 45minutes on a treadmill. The treadmill was set 25% up-hill inclination. The lower extremity 4 muscles activity including rectus femoris, tibialis anterior, gastrocnemius, biceps femoris was recorded and assessed by using EMG. And Heart rate(HR) and Rating of perceived exertion(RPE) were recorded and analyzed by 15minutes interval. The statistical analysis was two-way ANOVA with repeated measures to compare effects of hiking poles and steady walking time. The level of statistical significance for all tests was P<.05. The results of this study were following : Integrated EMG about four individual muscles doesn't have statistical significancy. However, the sum of IEMG of the four muscles was decreased some with poles than without poles(p<.0l) and IEMG about four muscles was rut different on steady walking time. Second, HR was increased significantly as time up(P<.01). RPE was decreased some with poles than without poles(P<.05) and RPE was increased significantly as time up(P<.01).

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.347-357
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• 2009

The purpose of this study was to compare EMG and GRF during a free throw. Seven pairs of surface electrodes were attached to the right-hand side of the body to monitor the flexor carpi radialis (FC), extensor carpi radialis longus (EC), biceps brachii (BB), triceps brachii (TB), rectus femoris (RF), tibialis anterior (TA) and medial gastrocnemius (GM). GRF data from two force platform were collected during a free throw. The results showed that the muscle activities in the unskilled group must be highly activated prior to the moment of release. This means that a skilled participant can shoot a free throw more efficiently while producing less muscle activeness than an unskilled participant. The DCP of unskilled group in the medio-lateral direction were greater than the corresponding values in skilled group. This showed that the unskilled group were not able to shoot the free throws stably. Thus, when a teacher or instructor teaches students how to shoot free throw, it is considered that the teacher show the learner how to use not only the upper limbs but also lower limbs on the basis of the efficent connecting movement and the flexibility in a stable procedure.

• Sleep Medicine and Psychophysiology
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• v.4 no.2
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• pp.164-171
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• 1997

Introduction : Periodic limb movement disorder (PLMD) is shown to common in patients with OSA and may become evident or worsened when treated with nasal continuous positive airway pressure (CPAP). Whether this is due to im proved sleep continuity. adverse nocturnal body positioning, uncovered by CPAP, or due to the CPAP stimulus is still debat-ed. We hypothesized that the increase in PLM activity following CPAP is associated with more supine-sleeping tendencies when being treated with CPAP. In the present work, we compared differences in the PLMD index (PLMI) and sleeping position of patients with sleep disordered breathing before and after CPAP treatment. Method : We studied 16 patients (mean age 46 yr, 9M, 7F) with OSA (11 patients) or UARS (5 patients) who either had PLMD on initial polysomnogram (baseline PSG) or on nasal CPAP trial (CPAP PSG). All periodic leg movements were scored on anterior tibialis EMG during sleep according to standard criteria (net duration; 0.5-5.0 seconds, intervals; 4-90 seconds. 4 consecutive movements). Paired t-tests compared PLMD index (PLMI), PLMD-related arousal index (PLMD-ArI), respiratory disturbance index (RDI), and supine sleeping position spent with baseline PSG and CPAP PSG. Results : Ten patients (63%) on baseline PSG and fifteen patients (94%) on CPAP PSG had documented PLMD ($PLMI{\ge}5$) respectively with significant increase on CPAP PSG(p<0.05). Ten patients showed the emergence (6/10 patients) or substantial worsening (4/10 patients) of PLMD during CPAP trial. Mean CPAP pressure was $7.6{\pm}1.8\;cmH_2O$. PLMI tended to increase from baseline PSG to CPAP PSG, and significantly increase when excluding 2 outlier (baseline PSG, $19.0{\pm}25.8/hr$ vs CPAP PSG, $29.9{\pm}12.5/hr$, p<0.1). PLMD-ArI showed no significant change, but a significant decrease was detected when excluding 2 outlier (p<0.1). There was no significant sleeping positional difference (supine vs non-supine) on baseline PSG, but significantly more supine position (supine vs non-supine, p<0.05) on CPAP PSG. There was no significant difference in PLMI during supine-sleeping and nonsupine-sleeping position on both of baseline PSG and CPAP PSG. There was also no significant difference in PLMI during supine-sleeping position between baseline PSG and CPAP PSG. With nasal CPAP, there was a highly significant reduction in the RDI (baseline PSG, $14.1{\pm}21.3/hr$ vs CPAP PSG, $2.7{\pm}3.9/hr$, p<0.05). Conclusion : This preliminary data confirms previous findings that CPAP is a very effective treatment for OSA, and that PLMD is developed or worsened with treatment by CPAP. This data also indicates that supine-sleeping position is more common when being treated with CPAP. However, there was no clear evidence that supine position is the causal factor of increased PLMD with CPAP. It is, however, suggested that the relative movement limitation induced by CPAP treatment could be a contributory factor of PLMD.

• Journal of Korean Physical Therapy Science
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• v.18 no.1
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• pp.11-19
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• 2011

Purpose: The purpose of this study is to understand the effect of balance and gait when simultaneous application of Kinesio Taping on the lower extremities is done to improve the pattern of hemiplegic patients asymmetric lower extremity. Methods: This study was performed with 7 patients who have hemiplegia symptoms due to stoke. The taping on the paralyzed side was done on tibialis anterior, gluteus medius, gluteus maximus and psoas major and the taping on the unparalyzed side was done on the calf muscle and quadriceps. Berg Balance Scale(BBS) and Time Up and Go Test(TUG) was used to assessment the balance and gait of the patient after the kinesio taping was done on the lower extremities. The results of the test was analyzed by Wilcoxon Signed Rank Test on SPSS(Ver. 10.1). Results: When the taping was done on the paralyzed side, there was a significant improvement of balance and gait in BBS and TUG. When the taping was done on the lower extremities, it showed significant improvement of balance and gait, compared to when the taping was only done on the paralyzed side, according to BBS and TUG. Conclusion: The result of this study shows that the simultaneous taping of the lower extremities of the hemiplegic patients improves balance and gait by improving the pattern of patients lower extremities.

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.139-149
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• 2014

The purpose of this study was to evaluate the effect of angle change of forefoot's adhesive outsole on the electromyographic activity (EMG) of the erector spinae and selected lower limbs muscle during downhill walking over $-20^{\circ}$ ramp. Thirteen male university students (age: $25.4{\pm}3.9$ yrs, height: $176.2{\pm}5.1$ cm, weight: $717.4{\pm}105.0$ N) who have no musculoskeletal disorder were recruited as the subjects. To assess the myoelectric activities of selected muscles, six of surface EMG electrodes with on-site pre-amplification circuitry were attached to erector spinae (ES), rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), lateral gastrocnemius (LG), and medial gastrocnemius (MG). To obtain maximum EMG levels of the selected muscles for normalization, five maximum effort isometric contraction were performed before the experimental trials. Each subject walked over $0^{\circ}$ and $20^{\circ}$ ramp with three different forefeet's EVA outsole (0, 10, $20^{\circ}$) in random order at a speed of $1.2{\pm}0.1$ m/s. For each trial being analyzed, five critical instants and four phases were identified from the recording. The results of this study showed that the average muscle activities of MG and LG decreased in $20^{\circ}$ shoes compared to $0^{\circ}$ and $10^{\circ}$ ones in the initial double limb stance (IDLS). In initial single limb stance (ISLS) phase, the average muscle activities of ES increased with the angle of forefoot's adhesive outsole, indicating that the increment of shoes' angle induce upper body to flex anteriorly in order to maintain balance of trunk. In terminal double limb stance (TDLS) phase, average muscle activities of TA significantly increased in $20^{\circ}$ outsole compared to $0^{\circ}$ and $10^{\circ}$ ones. There was no external forces acting on the right foot other than the gravity during terminal single limb stance (TSLS) phase, all muscles maintained moderate levels of activity.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.8
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• pp.771-782
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• 2017

This paper describes the development of a wearable robot to assist ankle power for the elderly. Previously developed wearable robots have generally used motors and gears to assist muscle power during walking. However, the combination of motor and reduction gear is heavy and has limitations on the simultaneous control of stiffness and torque due to the friction of the gear reducer unlike human muscles. Therefore, in this study, Mckibben pneumatic muscle, which is lighter, safer, and more powerful than an electric motor with gear, was used to assist ankle joint. Antagonistic actuation using a pair of pneumatic muscles assisted the power of the soleus muscles and tibialis anterior muscles used for the pitching motion of the ankle joint, and the model parameters of the antagonistic actuator were experimentally derived using a muscle test platform. To recognize the wearer's walking intention, foot load and ankle torque were calculated by measuring the pressure and the center of pressure of the foot using force and linear displacement sensors, and the stiffness and the torque of the pneumatic muscle joint were then controlled by the calculated ankle torque and foot load. Finally, the performance of the developed ankle power assistive robot was experimentally verified by measuring EMG signals during walking experiments on a treadmill.

• 재활복지
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• v.21 no.3
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• pp.147-163
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• 2017

The purpose of this study was to examine how horse-riding exercise would be effective on the stroke patients' muscle thickness of lower extremity. The 30 stroke patients who were hospitalized in a hospital located in G metropolitan city were selected for this study. These subjects were randomly placed in a horse-riding exercise group (n=15) and a control group (n=15). The horse-riding exercise group received three 20-minute exercises a week for a total of 6 weeks. An ultrasound imaging equipment was used to measured The thicknesses of the rectus femoris (RF), tibialis anterior (TA), medial gastrocnemius (MG), and gluteus medius (GM). After the completion of a 6-week exercise program, same measurement was conducted for all study subjects. The data were analyzed using a paired t-test and independent t-test to determine the statistical significance. As a result, muscle thickness was significantly differentiated before and after the intervention in each group. The thicknesses of all the four muscles significantly increased after exercise in the horse-riding exercise group. The thicknesses of the RF, GM, and TA significantly increased after exercise in the control group. In conclusion, horse-riding exercise increased the thickness of the lower extremity skeletal muscles by stabilizing the knees and activating the extensor muscles of the lower extremities.

• Journal of Convergence for Information Technology
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• v.11 no.3
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• pp.250-260
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• 2021

The purpose of this study is to investigate muscle function and symmetry index during whole body vibration exercise using lower extremity training posture for throwing athletes. For throwing athletes in their 20s(6 males, 4 females, age: 24.60±0.92years, height: 177.90±7.40cm, weight: 92.90±22.97kg), lower extremity training postures with squat, carphrase, and lunge movements. Whole body vibration exercise training was performed using. Tensiomyography(TMG) variables Time Delay(Td), Time Contraction(Tc), Time Sustain(Ts) Time Relaxation(Tr), and Displacement Maximumal(Dm) in the lower extremity joint muscles(biceps femoris(BF), gastrocnemius lateral(GL), gastrocnemius medial(GM), rectus femoris(RF), tibialis anterior(TA), lateral vastus(LV), medial latissimus(ML)), were measured to compare and analyze muscle activity, muscle fatigue, and left-right symmetry. The results of the study are left RF, VL, right VM (p<.05) in Td, VM (p<.05) in Tc, GM in Ts (p<.05), left RF in Tr, and right TA (p<. 05) showed a change. Therefore, it has been proven that various whole-body vibration training is an effective exercise with changes in muscle contraction, and stability of the core is secured by symmetry of the left and right muscles. For this reason, the whole body vibration exercise will have a positive effect on rehabilitation training, and it is believed that it will be able to improve performance.