• Physical Therapy Korea
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• v.28 no.1
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• pp.84-91
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• 2021

Background: A hip fracture may occur spontaneously prior to the hip impact, due to the muscle pulling force exceeding the strength of the femur. Objects: We conducted falling experiments with humans to measure the activity of the hip muscles, and to examine how this was affected by the fall type. Methods: Eighteen individuals fell and landed sideways on a mat, by mimicking video-captured real-life older adults' falls. Falling trials were acquired with three fall directions: forward, backward, or sideways, and with three knee positions at the time of hip impact, where the landing side knee was free of constraint, or contacted the mat or the contralateral knee. During falls, the activities of the iliopsoas (Ilio), gluteus medius (Gmed), gluteus maximus (Gmax) and adductor longus (ADDL) muscles were recorded. Outcome variables included the time to onset, activity at the time of hip impact, and timing of the peak activity with respect to the time of hip impact. Results: For Ilio, Gmed, Gmax, and ADDL, respectively, EMG onset averaged 292, 304, 350, and 248 ms after fall initiation. Timing of the peak activity averaged 106, 96, 84, and 180 ms prior to the hip impact, and activity at the time of hip impact averaged 72.3, 45.2, 64.3, and 63.4% of the peak activity. Furthermore, the outcome variables were associated with fall direction and/or knee position in all but the iliopsoas muscle. Conclusion: Our results provide insights on the hip muscle activation during a fall, which may help to understand the potential injury mechanism of the spontaneous hip fracture.

• Journal of Fashion Business
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• v.27 no.2
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• pp.39-51
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• 2023

The purpose of this study was to effectively improve the thigh muscles of adult women working from home due to COVID-19. In this study, ten adult women working from home performed 1) an electromyography test, 2) a static balance test on a balance board, and a 3) dynamic balance test by squatting on a Bosu ball four times: before electric muscle stimulation (EMS), after EMS, after high-intensity circuit training (HICT), and after EMS plus HICT. For this test, EMS was attached to a medical knee support to manufacture an EMS knee band that could be easily worn regardless of the location. For the experiment, EMS(electric muscle stimulation) was attached to the medical knee protector to manufacture an EMS knee band that can be easily worn regardless of location, and was measured based on the right foot. The study results confirmed that in all tests (electromyography test, static balance test on the balance board, and dynamic balance test by squatting on a Bosu ball), thigh strength improved in the order of treatment before EMS, after EMS, after HICT, and after EMS plus HICT. The study showed that people working from home or with activity restrictions due to COVID-19 had better exercise effects when wearing the EMS knee band and performing HICT, even in a small space.

• Journal of muscle and joint health
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• v.9 no.1
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• pp.28-39
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• 2002

Objective. The 12 forms of Sun-style Tai Chi exercise has been developed specifically for arthritis patients in order to reduce their symptoms and to improve physical functioning. This quasi-experimental study examined the changes in pain, balance, muscle strength and physical functioning in women with osteoarthritis at the completion of the 12 week Tai Chi exercise program. Methods. The patients with osteoarthritis who signed the consent form were screened by their primary physician according to the inclusion criteria and invited to the study. Total of 66 osteoarthritis women with an average age of 63 years were participated in the Tai Chi exercise. At the completion of 12 weeks, 34 patients completed both pretest and posttest measures with 48% of overall dropout rate. Outcome measures were physical symptoms, balance, muscle strength, physical functioning, and depression. Paired t-test was utilized to examine differences between pre and post-measures. Results. After participating in the Tai Chi exercise program, the women with osteoarthritis showed significant improvements in their physical fitness measures, and consequently in their physical functioning. In physical fitness test, there were significant improvements in balance, flexibility, muscle strengths of knee, grip, and back muscles after the Tai Chi exercise. However, No significant differences were found in pain and stiffness of their knee joints and depression measure. Conclusion. The 12 forms of Tai Chi exercise has been found safely applicable to the older women with osteoarthritis for 12 weeks, and effective in improving balance, flexibility, and muscle strengths, and consequently lessening difficulties of performing their activities of daily life.

• The Journal of Korean Physical Therapy
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• v.11 no.2
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• pp.1-4
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• 1999

The purpose of this study was to analyze the changes of the muscle strength and length according to the changes of evaluation postures. Subjects of this study were 13 male and 13 female students. 6 evaluation postures were selected for this study(K90H90, K90H45, K90H0, K70H90, K70H45, K70H0 ; K90=knee $90^{\circ}$ flexion, K70=knee $70^{\circ}$ flexion, H90=hip $90^{\circ}$ fleion, H45=hip $45\circ}$ flexion. H0=hip $0^{\circ}$ ). The peak torque and hamstring muscle length(from fibula head to ischial tuberosity) were measured at each postures. The peak torque level was evaluated by make use of the KIN-COM. The results were as follows : 1. The peak torque in male was significantly increased with changes of hip flexion angle but not in female(($90^{\circ}\;>\;45^{\circ}\;>0^{\circ}$). 2. The hamstring length and peat torque in male and female was significantly changed according to the alteration of evaluation postures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.538-546
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• 2017

The purpose of this study was to investigate the effect of neuromuscular electrical stimulation (NMES) and transcutaneous electrical nerve stimulation (TENS) on muscular strength, pain, range of motion and fear-avoidance in anterior cruciate ligament reconstruction (ACLR) patients. The subjects of this study who received ACLR after arthroscopic injury were divided into two groups: NMES (n=14) and TENS (n=14). Each group received intervention after routine physical therapy. Each electrotherapy intervention was applied regularly for a total of 12 times, 3 times a day (30 minutes) for 4 weeks. The evaluation by intervention method included isokinetic muscle strength in flexion and extension of the knee joint, pain, range of motion of the knee joint, and fear-avoidance beliefs. The results showed significant improvement in pain, range of motion, and fear-avoidance beliefs in both groups (p<0.05). However, there was a significant improvement in isokinetic knee flexion and extension strength only in the NMES group (p<0.05). There was no significant difference between the two electrotherapy methods in muscle strength, pain, range of motion, and fear-avoidance beliefs. These study results suggest that NMES and TENS can be effective intervention methods for pain, range of motion, and fear-avoidance response in patients with ACLR, but to improve muscle strength NMES may be more effective.

• Physical Therapy Korea
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• v.17 no.2
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• pp.1-9
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• 2010

To develop effective training methods for strengthening a weakened quadriceps femoris muscle in hemiplegic patients, we examined the effects of maximal isometric contraction of the nonparalyzed knee joint on the electromyographic activities of the paralytic muscle. An electromyogram (EMG) was used to record the electromyographic activities of the paralytic quadriceps femoris muscle in 27 hemiplegic patients. The maximal isometric contraction was measured for each subject to normalize the electromyographic activities. The maximal isometric extension and flexion exercises were randomly conducted when the knee joint angles of the nonparalyzed knees were $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$. The patients were encouraged to maintain maximal isometric contractions in both knee joints during each measurement, and three measurements were taken. A one-minute rest interval was given between each measurement to minimize the effects of muscle fatigue. An average from the three values was taken as being the root mean square of the EMG and was recorded as being the maximal isometric contraction. The electromyographic activity obtained for each measurement was expressed as a percentage of the reference voluntary contraction, which was determined using the values obtained during the maximal isometric contraction. The results of this study are summarized as follows: First, when the knee joint angle of the nonparalyzed knee was $0^{\circ}$, the electromyographic activities of the paralytic medial aspect of rectus femoris were related to measurement by a maximal isometric flexion exercise than by an extension exercise (p<.05). Second, when the knee joint angle of the nonparalyzed knee was $90^{\circ}$, the electromyographic activities of the paralytic lateral aspect of rectus femoris were related to measurement by a maximal isometric flexion exercise than by an extension exercise (p<.05). The results show that myoelectrical activities of paralytic quardriceps were not related to measurement angles and exercise directions of the nonparalized knee joint. Studies on various indirect intervention to improve muscular strength of patients with nervous system disorders of the weakened muscle should be constantly conducted.

• Archives of Orthopedic and Sports Physical Therapy
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• v.14 no.2
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• pp.45-53
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• 2018

Purpose: The purpose of this study was to investigate the effects of muscle activity and muscle strength according to verbal command volume during isokinetic and isometric quadricep exercises. Methods: To measure muscle activity and muscle strength, surface electrodes were attached to the participants, as they sat on a Biodex chair. The isometric exercise was performed three times, with maximum exercise at $30^{\circ}$ bending angle, based on a maximum extension state of the knee at $0^{\circ}$. The average holding time was unified to three seconds. In addition, the isokinetic exercise was performed three times, at $60^{\circ}/sec$. The verbal command ranged between 0∾60 dB and 0∾75 dB. Muscle activity was measured using surface electromyography (4D-MT, Relive, Gimhae, Korea). The Biodex System 4 was used to measure the isometric and isokinetic strength of the nodal line, and 4D-MT was used to measure muscle activity. Results: There were significant improvements in the maximal and relative muscle strengths, when the 0∾ 60 dB and 0∾75 dB verbal commands were applied with isokinetic extension/flexion (p<.05). The isokinetic exercise (0∾75 dB) group showed a significant difference in the vastus medialis oblique muscle activity change (p<.05), while the isometric exercise (0∾75 dB) group showed a significant difference in the rectus femoris muscle activity change (p<.05). Conclusions: Our results reveal that verbal commands effectively improve muscle activity and muscle strength during isokinetic and isometric quadricep exercises.

• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.85-93
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• 2014

The purpose of this study was to investigate a relationship among Taekwondo, soccer and gymnastic athletes their balance ability and lower extremity muscle strength, muscle endurance and also whether these variables show differences by sports type. For this purpose, 10 Taekwondo athletes, 10 soccer athletes and 10 gymnastic athletes that is a high school in I area were selected and their balance ability, isokinetic muscle strength and muscle endurance were measured by using force platform (AMTI) and isokinetic measurement (HUMAC NORM). Then the following results were obtained by conducting pearson product-moment correlation analysis and one-way ANOVA. In case of both right and left foot one-leg standing with open-eyes, there was a relation between both knee extension maximal muscle strength of Taekwondo, soccer, gymnastic athletes and balance ability, and in case of right foot one-leg standing with open-eyes, there was a relation between that is right plantar flexion and dorsi flexion maximum muscle strength and muscle endurance of Taekwondo, soccer, gymnastic athletes and their balance ability. Furthermore, in case of left dorsi flexion maximum muscle strength, there were significant differences in order of Taekwondo, gymnastics and soccer, and for isokinetic plantar flexion maximum muscle endurance, both right and left showed significant differences in order of Taekwondo, gymnastic and soccer.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.30 no.2
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• pp.13-26
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• 2024

Background: The most common form of injury in soccer is a hamstring strain. Eccentric bias exercises are crucial for reducing injury risk and improving sprinting performance. The purpose of this study was to compare a 4-week hip-dominant hamstring strengthening exercise program (HDE) with a knee-dominant hamstring strengthening exercise program (KDE) in youth soccer players. Method: The sample (n=31) was randomly divided into two groups: HDE (n=17) and KDE (n=14), with soccer players in HDE performing hip joint-dominant hamstring strengthening exercises and those in KDE performing knee joint-dominant hamstring strengthening exercises. Each intervention was conducted three times per week for four weeks. The outcome measures included the hamstring strength test (isometric strength test, eccentric strength test), knee joint range of motion (90/90 active knee extension; AKE) test, lower limb function test Y-balance test and Agility T-test. Results: Following the intervention, both groups showed significant improvement in isometric and eccentric hamstring strength on both dominant and non-dominant sides (p<.05). The AKE test showed significant improvement in the dominant leg (p<.05) and non-dominant leg only in KDE. The agility test significantly improved in HDE (p<.05). There was a slight improvement in the Y-balance test score; however, the difference was not statistically significant. There were no differences between the two groups in the values before, and after the intervention for all items. Conclusion: The hip-dominant and knee-dominant hamstring strengthening exercise should be coordinated and used based on the environment during hamstring injury prevention training.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.4
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• pp.675-683
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• 2010

Purpose : The purpose of this study was to evaluate the effect of Whole body vibration exercise(WBVE) in patient with chronic stroke. Methods : Thirty patients were divided into two groups by randomly experimental group(14 subject) and control group(16 subject) in a single blinded, randomised study. experimental group was conducted for the 6-weeks WBVE program and had a structured exercise program for 16 minutes, 5 days per week and control group was conducted for the shame exercise program. Outcome variables included the knee extensor strength, Berg balance scale, Timed up and go test at 0 and 6 weeks. Results : The experimental group tended to improve more than the control group in balance(Berg balance scale) and walking ability(Timed up and go test). There were no trends in differences in change scores by the knee extensor strength. Conclusion : WBVE program may be helpful to improve knee extensor strengthening, dynamic balance and walking ability for patients with chronic patients.