• Journal of the Korean Academy of Clinical Electrophysiology
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• v.3 no.1
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• pp.49-59
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• 2005

This study assigns each 8 of 24 normal persons to control group(Group I), strength increase group(Group II) and endurance increase group(Group III) to analyze differences in changes of strength and endurance with surface electromyography and kinetics according to application modes of neuromuscular electrical stimulation(NMES). Group I had not any treatment, group II performed 15 repeated contraction with 60% intensity of maximal voluntary isometric contraction(MVIC) by setting 10-sec on time and 50-sec off time and group III conducted 30 repeated contraction with 30% intensity of MVIC by setting 10-sec on time and 20-sec off time. For neuromuscular electrical stimulation, 2,500 Hz of Russian current, 35 pps of pulse rate and 200 of pulse width. Neuromuscular electrical stimulation was conducted by five times for total 4 weeks. Before and after experimentmotor unit action potential of vastus medialis, rectus femoris and vastus lateralis were measured with sEMG, median frequency(MDF) was analyzed, and thus the following results were obtained. There was significant difference in the period of measuring vastus medialis and rectus femoris in change of MDF and interaction among groups with analysis of surface electromyography before and after neuromuscular electrical stimulation(p<.001) and in particular, there was a remarkable change among groups according to the period of measurement. In conclusion, NMES influenced changes of strength and endurance according to its application modes and in particular, it was found that strength increment application had a significant influence on strength increment in applying short-time NMES.

• The Research Journal of the Costume Culture
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• v.21 no.4
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• pp.606-611
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• 2013

It has been reported that tight sportswear could have complicated influence on physiological function of human body. The purpose of this present study was to investigate the effect of wearing gradient compression tights (GCT) on muscle strength and EMG activity during repeated isokinetic muscle contractions. Four healthy male undergraduate students performed maximal voluntary isokinetic concentric muscle contractions on biomechanical test and training systems with GCT and loose pants as control (Cont) respectively. During each test, the peak torque of extensor and flexor contractions and the surface electromyography (sEMG) of the rectus femoris and medial gastrocnemius was recorded simultaneously, the peak torque was recorded as an indicator of muscle strength, and the average amplitude and mean power frequency of sEMG were calculated as indicators of EMG activity. The results showed that: the peak torque decreased gradually during continuous muscle contractions both when the Cont and GCT were worn, average sEMG and mean power frequency declined along with the repetitions of muscle contractions for both wearing conditions, and the change tendency was consistence with that of peak torque. There was no obvious difference between the peak torque recorded wearing the Cont or wearing GCT, but when GCT were worn, average sEMG was lower and mean power frequency was higher than the Cont condition. In 24 samples obtained from four subjects, 80% of results showed the same trend. So we could make a conclusion that wearing GCT had no obvious effect on the improvement of muscle strength, but it would affect the EMG activity positivly.

• Journal of the Korea Convergence Society
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• v.10 no.5
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• pp.79-84
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• 2019

The purpose of this study was to examine the effects of treadmill exercise on the aerobic function of dance majors in their 20s. The subjects consisted of 10 female Korean dance majors in their 20s as an experimental group and 10 normal female college students as a control group, and both groups conducted treadmill gait training. Their heart rate recovery (HRR), maximal oxygen uptake (MOU), maximal voluntary ventilation (MVV), and lactate recovery rate (LRR) were measured before and after the experiment. The comparison of changes in the subjects' aerobic function before and after the experiment showed that the experimental group gained more significant effects on HRR and LRR than the control group. Therefore, treadmill gait training may help Korean dance majors to improve their basic physical strength by enhancing their aerobic function, and the findings of this study are likely to provide basic data to support scientific exercise prescriptions.

• Journal of Korean Physical Therapy Science
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• v.7 no.2
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• pp.711-725
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• 2000

The purpose of this study was to determine the effects of knee flexor isokinetic training on the mean peak torque of knee muscles and hamstrings-to-quadriceps ratio(H/Q ratio) in hemiplegia able to walk independently for more than 10 meters, to analyze the effect of torque increasing on functional aspects; fatigability and ambulation times, also. Forty-one adult subjects with hemiplegia secondary to a stroke partipated in this study. All participants were in/out patients at the College of Medicine, Pocheon CHA University, Pundang CHA General Hospital. The patients were allocated to two groups: one group exclusively for isokinetic maximal voluntary knee flexor training at $150^{\circ}$/sec(n=20) and the other exclusively for isokinetic maximal voluntary knee flexor training from $30^{\circ}$/sec to $150^{\circ}$/sec (n=21) gradually. The allocation was performed according to patient age, sex, affected side to minimize imbalance between the two training groups. Training was carried out from February 14th, 2000 to April 15th, 2000. Analysis of the data was done by means of t-test, x2-test, paired t-test, ANOVA, and multiple regression analysis. The results of this study were as follows: 1. There were no significant differences between the two groups in mean peak torque of knee muscles and relative decreases in knee extensor mean peak torque with increased knee flexor velocities before training (P<.05). 2.There was no significant differences between the two groups in the H/Q ratio, and no relative increases with increased knee flexor velocities before training. 3. there were significant changes in mean peak torque in group A after training(P<.05), but no significant differences as the velocity increased 4.there were significant changes in mean peak torque in group B after training(P<.05), but no significant differences as the velocity increased 5.there were no significant differences between the two groups, and no significant differences in mean peak torque increase rate between the groups with increased knee flexor velocities after training 6.H/Q ratio increased with increased knee flexor velocities between the two groups, but not statistically And there was no significant differences between the groups with increased knee flexor velocities 7.After training, Ambulation time and its decreasing rate decreased significantly in group B (P<.05) 8Before and after training, there was no significant differences between the groups in the fatiguability 9. In the multiple regression analysis, mean peak torque increase rate of the knee extensor and flexor were higher in group B than A(P<.05), and significantly higher with increased knee flexor velocities (P<.05) Also, training method influenced on Ambulation times decreases significantly(P<.05). Results indicated that knee flexor isokinetic training was effective to knee extensor and flexor mean peak torque increase in the hemiplegia able to walk independently for more than 10 meters. Therefore, we were able to conclude that gradual training from low to high velocity was more effective in the increase of mean peak torque of knee joint and decrease of Ambulation times than training only at high velocity.

• Journal of the Korea Convergence Society
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• v.7 no.2
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• pp.43-52
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• 2016

The purpose of this study was to suggest the effective squat exercise position to strengthening vastus medialis oblique, and vastus lateralis in quadriceps. Subjects were twenty patients with patellofemoral pain syndrome (PFPS) volunteered to participate in this study. All subjects were applied to static squat convergence exercise with knee flexed $45^{\circ}$, $60^{\circ}$, and $90^{\circ}$ for 30 seconds total 5 times. Measurement variables were maximal voluntary isometric contraction (MVIC) of the quadriceps, Q angle and length of thigh. Those were measured before and after the squat exercise on knee joint angle, change rate of which were used for statistical analysis. As a result, squat exercise with knee flexed $90^{\circ}$ increase significantly among knee joint angle in the MVIC change rates of quadriceps (p<.05), however the rates of Q-angle and length change of thigh showed no significant difference. Therefore, this findings suggest that squat exercise with knee flexed $90^{\circ}$ strengthen quadriceps effectively in patients with PFPS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4418-4426
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• 2010

Muscle fatigue often induces deterioration of postural balance and muscle contraction, such as strength or maximal voluntary contraction(MVC). This study was to investigate the effects of transcutaneous electrical stimulation(TENS) applied to the fatigued muscles on postural imbalance and decline in muscle strength following fatigue of triceps surae. For the 4 months from March, 2010, twenty healthy subjects without vestibular disease and visual disturbance were recruited and induced muscle fatigue of triceps surea performed by repeated voluntary contraction. TENS was applied to gastocnemius immediately after development of muscle fatigue. Postural sway length, velocity and MVC were recorded under these conditions: pre-fatigue, post-fatigue, and TENS application to fatigued muscle during post-fatigue. Muscle fatigue increased postural imbalance as expressed by sway length and velocity and decreased muscle contraction(p<.05), while TENS improved the postural imbalance and MVC following muscle fatigue during stance(p<.05). The results suggested that fatigue on plantar flexor is associated with postural balance and muscle contraction, and TENS application to fatigued muscle was effective in improving postural imbalance and decline in muscle strength following muscle fatigue. TENS will be an effective method in exercise, working environment and daily life.

• Physical Therapy Korea
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• v.27 no.2
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• pp.93-101
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• 2020

Background: For performing various movements well, cooperation between the muscles around the scapula and shoulder has been emphasized. Taping has been widely used clinically as a helpful adjunct to other physiotherapy methods for shoulder pathology and dysfunction treatment. Previous studies have evaluated the effect of taping techniques using dynamic tapes on shoulder function and pain. However, no study investigated the electromyographic (EMG) changes in the shoulder muscles. Objects: This study aimed to investigate the effect of the upper limb offload taping technique using a dynamic tape on EMG activities of the upper trapezius (UT), lower trapezius, serratus anterior (SA), and middle deltoid (MD) muscles during scaption plane elevation. Methods: A total of 26 healthy subjects (19.85 ± 6.40 years, male = 20) volunteered to participate in this study. The subjects were instructed to perform scaption elevation with and without dynamic taping on the shoulder. Shoulder elevation strength tests were performed at 100%, 75%, 50%, and 25%, for the maximal isometric contraction force. Results: There were statistically significant interaction effects between the taping application and shoulder scaption elevation force in EMG activities in the UT (p < 0.05) and MD (p < 0.05). EMG activities in the UT showed significant increases in 50%RVC (reference voluntary contraction, p < 0.05) and 25%RVC (p < 0.01). Furthermore, the EMG activity of the SA significantly increased in 50%RVC (p < 0.01) and 25%RVC (p < 0.01) after dynamic taping. For the MD, the EMG activity level significantly decreased in 100%RVC (p < 0.05). Conclusion: These results indicated that upper limb offload dynamic taping application affects the muscle activities of some shoulder muscles depending on different scaption elevation strength levels. Therefore, we suggest that the upper limb offload dynamic taping can be applied to the shoulders when patients need middle deltoid inhibition or upper trapezius facilitation, such as patients with shoulder impingement syndrome.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.83-92
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• 2017

PURPOSE: The purpose of this study was to investigate the effect of the elastic band and stretching exercise program on ankle joint maximal voluntary isometric contraction (MVIC) and plantar pressure in high-heel wearing women in their 20s. METHODS: Twenty women in their twenties were randomly assigned to the experimental group (n=10) and the control group (n=10). The experimental group (n=10) performed the elastic band exercise program, while the control group (n=10) performed the stretching exercise program. Both exercise programs were performed three times a week for a total of four weeks. The BTE Primus RS was used in order to measure the ankle joint MVIC during dorsiflexion, plantar flexion, inversion, and eversion. Maximum pressure ($N/cm^2$), average pressure ($N/cm^2$) were measured using the Pedoscan. SPSS v. 21.0 software was used for all statistical analyses in this study. RESULTS: The measurement of the ankle joint's MVIC revealed that in inversion, a significant change in both feet was seen in both the experimental and control groups. In eversion, there was a significant change in both feet only in the experimental group. In terms of the rest of the results, no significant changes were visible. With regard to the plantar pressure, no significant results were seen for either foot in the comparison between or within the groups. CONCLUSION: Exercise program using elastic band and exercise program using stretching were effective on MVIC of ankle joint muscles, although it had no effect on changes of plantar pressure.

• Physical Therapy Korea
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• v.20 no.1
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• pp.28-35
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• 2013

The purpose of this study was to determine the effects of warm-up and cool-down exercises on pain and muscle activation of delayed onset muscle soreness after intense exercise. Delayed onset muscle soreness was caused by the eccentric exercise in the elbow flexor muscle of the non-dominant upper limb. Forty-four subjects volunteered to participate in this study and were randomly assigned to one of the following groups: warm-up and cool-down group, only warm-up group, only cool-down group, or control group with no intervention. The level of perceived pain using the visual analogue scale and electromyographic activation change in maximal voluntary isometric contraction were measured 4 times at the following times: 10 min, 24 hr, 48 hr, and 72 hr after the exercise. The results revealed the main effect between the groups and interaction effect between the group and measurement session (p<.05). The warm-up and cool-down group showed most favorable results with respect to reduced perceived pain level and increased muscle strength in most measurement sessions, and the only warm-up group showed significantly more decreased pain level than the control group at 24 hr and 48 hr and more increased muscle activation than the cool-down group at 48 hr (p<.05). However, there were no significant differences in pain level and muscle activation between the only cool-down group and control group at all measurement sessions (p>.05). The findings suggest that the warm-up exercise performed before an intense exercise had beneficial effects on the symptoms of delayed onset muscle soreness, whereas cool-down exercise performed after the intense exercise did not.

• Physical Therapy Rehabilitation Science
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• v.10 no.3
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• pp.244-250
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• 2021

Objective: The purpose of this study was to investigate the effect of sprinter pattern bridging exercise using theraband on activation of lower extremity and abdominal muscle and to find out postures that can effectively improve abdominal and lower extremity muscle strength and increase abdominal stability. Methods: This study was designed as a cross-sectional study. The following research was done with applicants attending S university in Seoul to compare the difference in muscle activity between one-leg-Support bridging exercise and sprinter-pattern bridging exercise using theraband. For 48 study participants, we first measured their MVC. Then, we applied one-leg-support bridging exercise and sprinter-pattern bridging exercise at random order. These data were expressed as the percentage of maximal voluntary contraction (%MVC).Electromyography analysis was performed by measuring the external obliques, internal obliques, biceps femoris, and gluteus maximus. Results: There was a statistically significant increment of muscle activity in external and internal oblique muscle(p<0.001)by sprinter-pattern bridging exercise using theraband. On the lower body, statistically significant increment of muscle activity in biceps femoris and gluteus maximus was found(p<0.05). On the other hand, on erector spinae, there was statistically significant decrease in muscle activity(p<0.05). Conclusions: Efficient treatment is expected when sprinter-pattern bridging exercise using theraband is applied clinically.For patients with chronic knee and ankle pain who have difficulty bearing weight, including low back pain and internal rotation of the femur, starting with a low weight bearing, we think it will be helpful in planning systematic training aimed at progressively strengthening the lower extremities.