• Journal of International Academy of Physical Therapy Research
• /
• v.3 no.2
• /
• pp.422-428
• /
• 2012

The present study purposed to examine the effects of transcutaneous electrical nerve stimulation, self-stretching and functional massage on the recovery of muscle contraction force for muscle fatigue caused by sustained isotonic contraction. The subjects of this study were 45 healthy students. They were divided into transcutaneous electrical nerve stimulation group(n=15), self-stretching group(n=15) and functional massage group(n=15), and using Primus RS. We observed the pattern of changes in maximal voluntary isometric contraction force(MVIC) after causing muscle fatigue in quadriceps femoris muscle through sustained isotonic contraction. Maximal voluntary isometric contraction force(MVIC) were greatly increased after transcutaneous electrical nerve stimulation, self-stretching and functional massage. In the comparison of recovery rate of muscle contraction force for muscle fatigue caused by sustained isotonic contraction among the treatment groups, it did not show any significant differences. However, it showed that each treatment may be effective in recovery of muscle fatigue caused by sustained isotonic contraction.

• Physical Therapy Korea
• /
• v.14 no.3
• /
• pp.9-15
• /
• 2007

The purpose of this study was to investigate electromyographic activities of the flexor digitorum superficialis (FDS) and the flexor carpi ulnaris (FCU) by the shape of the ultrasound head. Twelve healthy subjects participated and performed ultrasound therapy with a round head and a long handled head during each 5-minute application. Electromyographic activities of the FDS and FCU were recorded by surface electrodes and normalized by maximal voluntary isometric contraction (MVIC) values. There was no difference in the muscular fatigue of FDS and FCU as determined by the shape of the ultrasound head (p>.05). Without the shape of head, the mean power frequency decreased with the time. There also was no difference in %MVIC of the FDS and FCU as determined by the shape of the ultrasound head (p>.05), but the force exerted exceeded 20%MVIC. There was however a significant difference in the amount of cumulative workload of the FDS and FCU as determined by the shape of ultrasound head (p<.05). The workload was however not affected by the shape of the ultrasound head. Constant static grasp of ultrasound transducer head during ultrasound therapy is considered a high risk factor of work-related musculoskeletal disease.

• Journal of Society of Preventive Korean Medicine
• /
• v.12 no.3
• /
• pp.115-128
• /
• 2008

Purpose : This study was performed to distinguish the muscle activation of vastus medialis and biceps femoris through open and closed kinetic chain exercise. Methods : 31 healthy male and female students in Daegu Health College were participated in this study. All subjects were conducted three types open and closed kinetic chain exercises to examine muscle activity during the last four seconds using the sEMG system. Collected EMG data were normalized using the maximal voluntary isometric contraction(MVIC). Results : MVIC of each muscle was showed significantly increased(p<0.5). In the case of open chain exercise, the type 3 exercise most increased than type 2 and 3 exercise in vastus medialis than biceps femoris muscle. The closed chain exercise presented type 6 exercise most increased than type 4 and 5 exercise in biceps femoris than vastus medialis. Conclusion : This study finally proved that muscle activity which maintains stability of knee differ from depending on the types of exercises. Therefore, the combination of the two chain exercises is believed to greatly contribute to increments in muscle activity.

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

• Journal of the Korean Society of Physical Medicine
• /
• v.10 no.2
• /
• pp.63-71
• /
• 2015

PURPOSE: The purpose of this study to investigate the effects of exercise on lumbar stabilization in muscle activity and isokinetic muscle strength of female with chronic low back pain. METHODS: The candidates was chose to twenty women in their 30s and 40s complaining back pain for over 12 weeks and consist of 10 people for lumbar stabilization and general physical therapy group(PL group), another 10 people for general physical therapy group(GP group). Lumbar stabilization exercise was conducted for 8 weeks and was comprised of 60 minutes for two times a week. In order to examine the effects of lumbar stabilization, results in the present study were analyzed maximal voluntary isometric contraction (MVIC) using electromyogram to measure muscle activity and isokinetic performance including peak torque and average power at the pre to post. RESULTS: The following are results in this study. The MVIC and isokinetic muscle strength were gradually increased in all group. As the result of the test of the MVIC and isokinetic muscle strength, the difference of lumbar stabilization and general physical therapy group is statistically more significant than that of general physical therapy group. CONCLUSION: In the present study, results indicate that lumbar stabilization helps to improve the muscle activity and isokinetic muscle strength.

• PNF and Movement
• /
• v.9 no.3
• /
• pp.1-9
• /
• 2011

Purpose : The purpose of this study was to find the effects of the transverse abdominis/internal abdominal oblique (TrA/IO), multifidus (MF) muscles while stabilization exercise was performed in a four-point kneeling position on the unstable surface. Methods : Twenty healthy adults volunteered to participate in this study. Each subject was instructed regarding maximum voluntary isometric contractions (MVIC) and stabilization exercise in four-point kneeling on the unstable surface. While MVIC and stabilization exercise of individual muscles were being performed, activation of the muscles was measured using surface electromyography (EMG). Activation of the muscles while performing stabilization exercise in four-point kneeling on the unstable surface was normalized to a percentages of the MVIC. Results : TrA/IO, MF muscles showed no significant differences among the surfaces. Conclusion : Activation of the trunk muscles while performing stabilization exercise in four-point kneeling does not effect on the surface.

• Journal of the Korea Convergence Society
• /
• v.7 no.2
• /
• pp.43-52
• /
• 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 International Academy of Physical Therapy Research
• /
• v.9 no.4
• /
• pp.1608-1613
• /
• 2018

The purpose of this study was to investigate the effects of sling exercise on muscle activity and balance on football players with chronic ankle instability. Eight subjects performed Biodex and sling exercises for four weeks and compared the muscle activity and balance ability of the uninjured and injured feet. Stable and unstable foot % MVIC did not change significantly after treatment in all muscles. The total balance ability was not significantly different between the two groups, however, increased only in the unstable side. The anterior/posterior balance ability also represented no significant difference between the groups and was significantly improved only in the unstable side. The medial/lateral balance ability was not significantly different between the groups and was significantly improved only in the unstable side. This study suggests that sling exercise contributes to improving % MVIC, total balance ability, anterior/posterior balance ability, and medial/lateral balance ability of the unstable side.

• Korean Journal of Applied Biomechanics
• /
• v.21 no.4
• /
• pp.467-477
• /
• 2011

This study was performed to investigate the effects of tibial rotation while going up stair on muscle activity of vastus medialis oblique and vastus lateralis, and on patellar displacement. The subjects included 30 people (male: 15; female: 15) who were randomly assigned to the tibial internal-rotation, neutral-rotation, and external-rotation groups. The subjects went up the stair while performing the assigned rotations, and the rotation of the hip and the displacement of the patella were measured using a 3D motion analyzer. In addition, the maximum voluntary isometric contraction (MVIC) of the vastus medialis oblique and vastus lateralis were measured using surface electromyogram. On the tibial internal rotation, the hip rotation significantly appeared in the same direction and so did on the tibial neutral and external rotations(p<.001). Although the MVIC of the vastus medialis oblique and vastus lateralis did not significantly differ by tibial rotation during the stair ascent, the MVIC of the vastus medialis oblique was higher than that of the vastus lateralis during the internal and neutral rotations (p<.05). In addition, during the stair ascent, the displacement of the patella was more significant during the tibial external rotation than during the tibial internal and neutral rotations(p<.001). Thus, patients with patellofemoral pain are required to be considered the effects of tibial rotation for their rehabilitation.

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