• Journal of Korean Orthopaedic Sports Medicine
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• v.7 no.1
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• pp.8-14
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• 2008

Elbow joint injuries during exercise mostly occur by repeated stress to the joint than direct trauma. A pitcher who uses his arm above his head is most likely to be injured. So learning the right way to exercise and gaining the strength by maturating the body are essential for diminishing the chance of injury. On lateral ulnar tendon injury, which is most commonly injured area on elbow joint, pitchers generally complain of pain in arm movement above head and reduction of velocity, accuracy, and number of pitching. When there is pain on upper arm in harsh using, the stress fracture must be thought and epicondylar physis fracture of medial arm can occur by repeated abduction stress and contraction of flexors on forearm on children with immature skeleton. Osteochondritis dissecans of capitullum occur in young athletes who use there upper limb continuously lifting weights and gym work. And stress of abduction-extension includes damage of soft tissue and bone components, post medial crush syndrome, lateral ulnar ligament injury, extensor-abductor injury, stress of radius- capitullum are in this category.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.97-108
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• 2006

C. H. OH, S. N. CHOI, T. G. NAM, The Kinematic Analysis of the Tennis Flat Serve Motion, Korean Jiurnal of Sports Biomechanics, Vol. 16, No. 2, pp. 97-108, 2006. By the comparison and the analysis of the different factors during the tennis flat serve motion such as the required time per section, the movement displacement of the racket, the velocity of the upper limbs joints, the physical center of gravity, and the angle and the angular velocity of the upper limbs joints between an ace player and a mediocre player, these following results were drawn. First, the experiment result of the total time required per section in a tennis flat serve motion showed that an ace player was faster than a mediocre player by 0.4 seconds. This result suggested that it was required to increase the speed of the racket head by a swift swing to perform an effective flat serve motion. Second, the experiment result of the movement displacement of the racket in the tennis flat serve motion showed that an ace player greatly moved toward the left side on an x-axis. But both an ace and a mediocre player were shown to be at the similar points on a y-axis at the moment of the impact of the racket. An ace player was also shown to be located at a higher position on a z-axis by 0.23m. Third, the velocity of the center of gravity of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fourth, the velocity of the upper limb joints of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fifth, the experiment result of the speed of the racket head in tennis flat serve motion showed that a mediocre player was faster than an ace player in the first phase, but the latter was faster than the former in the second, third, and the fourth phases. Sixth, at the moment of impact of a tennis flat serve, an ace player had greater flexion of the angle of the wrist joints by an 11.8 degree than a mediocre player. An ace player also had greater extension of the angle of the elbow joint and the shoulder joint respectively by a 5.2 degree and a 1.4 degree with a mediocre player. Seventh, an ace player had greater angular velocity of the upper limb joints and the hip joints than a mediocre player at the moment of the impact of tennis flat serve. Eighth, an ace player was shown to have a greater change of the forward and the backward inclination (or the anterior and posterior inclination) of the upper body

• Physical Therapy Korea
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• v.16 no.2
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• pp.1-8
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• 2009

Anticipatory postural adjustments is an example of the ability of the central nervous system to predict the consequence of the mechanical effect of movement on posture and helps minimize a forth coming disturbance. The aim of this study was to evaluate the sequence of activation of the trunk muscles during the performance of hip and shoulder movement and to determine the relationship between anticipatory activity and subjects' motor and functional status in subjects with hemiplegia post stroke. Twenty-four poststroke hemiparetic patients enrolled in this study. Electromyographic activity of the lumbar erector spinae, latissimus dorsi, and of the obliquus internus muscles was recorded bilaterally during flexion of both arm and from the rectus abdominis, obliquus externus, and obliquus internus muscles during flexion of both hip. Onset latencies of trunk muscles were partially delayed in the subjects with hemiplegia post stroke (p<.05). With upper limb flexion, the onset of erector spinae muscle and latissimus dorsi muscle activity preceded the onset of deltoid on both side respectively (p<.05). A similar sequence of activation occurred with lower limb flexion. Also the onset of external oblique muscle and rectus abdominis muscle activity preceded the onset of rectus femoris muscle on both side (p<.05). Major impairments in the activity of trunk muscles in hemiparetic subjects were manifested in delayed onset between activation of pertinent muscular pairs. These problems were associated with motor and functional deficits and warrant specific consideration during physical rehabilitation of post stroke hemiparetic patients.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.3
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• pp.125-131
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• 2016

PURPOSE: The objective of this research is to investigate the effectiveness of mental practice on function and muscle activation of upper extremity (UE) in stroke patients. METHODS: The mental practice was conducted on 12 subjects for 10 minutes and the related existing work treatment for 20 minutes. The evaluation for the function of UE proceeded with Fugl-Meyer assessment of motor function (FMA) and muscle activity analysis instrument. Furthermore we analyzed patients' reaching activity by two stages, reaching phase and returning to original position phase. RESULTS: According to the research results, the subjects' upper limb function improved in all of the measured items and the total scores after the mental practice (p<.05). In muscle activity, CCR value was used to efficiently analyze the patients' reaching activity in the two stages of reaching stage and returning to the original position phase. While the elbow movement only had a bit of positive change (1.1%) in the reaching stage, both the shoulder (-12.3%) and elbow (-18.2%) movements had a positive change in the returning to original position phase. CONCLUSION: This research confirmed that the mental practice is effective for the enhancement of UE function for stroke patients. The result of this research can contribute to the progress of mental practice in clinical environment.

• PNF and Movement
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• v.14 no.1
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• pp.49-52
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• 2016

Purpose: The purpose of the present study was to examine the effects of the area of the base of support formed by the human body on the maximal voluntary isometric contraction of upper limb muscles. Methods: The study was conducted with 20 normal adults. To identify changes in the base of support, the maximal voluntary isometric contraction of the biceps muscle was measured in a standing position, a sitting position, and a lying position for each subject. The sizes of the base of support formed in the standing, sitting, and lying positions were set to 1, 2, and 3 respectively, based on the sizes, to analyze the correlations. The maximal voluntary isometric contraction of the biceps muscle was measured using surface electromyograms (EMGs) (Noraxon DTS, Germany). Results: The results showed negative correlations in which, as the size of the base of support increased, the maximal voluntary isometric contraction of the biceps muscle decreased. Conclusion: Changes in the base of support of the body affect the maximal voluntary isometric contraction of the upper limbs. Therefore, when resistance exercises are applied for muscle strengthening, the positions should be changed considering the changes in muscle activity according to those positions. In addition, when EMGs are used to measure the maximal voluntary isometric contraction, the measurements should be conducted in the same positions, considering muscle activity that changes according to the base of support and positions, for data quantification.

• PNF and Movement
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• v.16 no.3
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• pp.415-424
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• 2018

Purpose: This study aimed to determine the effects of various wheelchair handling directions on the upper limb muscle activities of wheelchair attendants while climbing a ramp. Methods: For the study participants, healthy males over 20 years of age were chosen, and the order of the direction of wheelchair handle grip was determined using a randomized method. The handling directions for pushing the wheelchair up a ramp included a general grip with ulnar deviation, a medial grip with wrist pronation, and a neutral grip with a neutral wrist. The muscle activities in the participants' upper limbs were measured using surface electromyography. For statistical data processing, SPSS 18.0 was used to perform repeated measures ANOVA in order to compare the muscle activity among the intervention groups. A contrast test was also conducted among the participants. The significance level (${\alpha}$) was set to 0.05. Results: There was a significant difference between groups using a general grip and a medial grip in the biceps brachii, triceps brachii, and flexor carpi radialis muscles (p<0.05). There was also a significant difference between using a general grip and a neutral grip in the biceps brachii and flexor carpi radialis muscles (p<0.05), and there was a significant difference between using a medial grip and a neutral grip in the biceps brachii and extensor carpi radialis brevis muscles (p<0.05). Conclusion: In this study, the wheelchair assistants' wrist muscle activity was the lowest with a neutral grip while ascending a ramp. Accordingly, this study proposes that wheelchair assistants push wheelchairs up ramps with a neutral grip.

• Journal of the Ergonomics Society of Korea
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• v.28 no.1
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• pp.9-19
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• 2009

Repetitive movement, inadequate working posture, overuse of force, physical contact with sharp edge, vibration and temperature were well known risk factors of WMSDs (Work-related Musculoskeletal Disorders). Many researchers have investigated the relationship between inadequate working postures and incidences of WMSDs of the upper extremities, whereas relatively few researchers have tried to evaluate workload associated with the lower-body postures. The effects of lower-limb postures including various knee flexion angles on the subjective discomfort, heart rate and EMG of lower-limb muscles were investigated in this study. Thirty graduate students were asked to maintain thirteen different body postures, and heart rate and EMG data of five muscle groups (electro spine, biceps femoris, vastus medialis, gastrocnemius and tibialis anterior) from each posture were collected during fifteen minutes sustaining tasks. All participants were also asked to report their discomfort ratings of body parts. Results showed that high subjective discomfort ratings and heart rates were reported at the postures of knee angles of $60^{\circ}$ and $90^{\circ}$, whereas low discomfort ratings were founded at the postures of chair heights with 20cm, 40cm, and sitting with crossed legged. The change of median frequency for each muscle group during fifteen minutes tasks was investigated for each body posture to evaluate the relationship between muscle fatigue and body posture. It was found that the trends of changes of median frequency were different based on muscle group as well as lower-limb body posture from this study.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.139-147
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• 2007

The aim of this study was to evaluate effects of short-tenn repetitive-bilateral excercise on the activation of motor network using functional magnetic resonance imaging (fMRI). The training program was performed at 1 hr/day, 5 days/week during 6 weeks. Fugl-Meyer Assessments (FMA) were performed every two weeks during the training. We compared cerebral and cerebellar cortical activations in two different tasks before and after the training program: (1) the only unaffected hand movement (Task 1); and (2) passive movements of affected hand by the active movement of unaffected hand (Task 2). fMRI was performed at 3T with wrist flexion-extension movement at 1 Hz during the motor tasks. All patients showed significant improvements of FMA scores in their paretic limbs after training. fMRI studies in Task 1 showed that cortical activations decreased in ipsilateral sensorimotor cortex but increased in contralateral sensorimotor cortex and ipsilateral cerebellum. Task 2 showed cortical reorganizations in bilateral sensorimotor cortex, premotor area, supplemetary motor area and cerebellum. Therefore, this study demonstrated that plastic changes of motor network occurred as a neural basis of the improvement subsequent to repetitive-bilateral excercise using the symmetrical upper-limb ann motion trainer.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.3
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• pp.2140-2146
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• 2020

Background: Stroke patients exhibit arm global synkinesis (GS), involuntary movement due to muscle weakness and irregular muscle tension. But currently there are few studies examined the effects of GS on activates of daily living in stroke patients. Objectives: To investigate the effects the effects of task-oriented bilateral movements, which promote brain plasticity and are based on neurological theory, using the unaffected arm and the affected arm. Design: Quasi-randomized trial. Methods: Twenty stroke patients were randomly assigned to experimental group I (n=10) and experimental group II (n=10). Before the intervention, arm GS was measured using surface electromyography, and the Motor Activity Log evaluated the quantitative and qualitative uses of the affected arm in daily life. The same items were measured four weeks later. Results: The changes in the GS of the arm of experimental group I showed statistically significant differences only in bending motions (P<.05). Both groups showed statistically significant differences in the amount of use (AOU) and the quality of movement (QOM) scores (P<.01). Comparing the groups, statistically significant differences in GS appeared during bending motions (P<.05), and in the AOU (P<.01) and the QOM scores (P<.05). Conclusion: The intervention in GS reduced the abnormal muscle tension of the affected side by increasing the use of the ipsilateral motor pathway, indicating its effectiveness in improving upper limb functions with smooth contraction and relaxation of the muscles.

• Korean Journal of Applied Biomechanics
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• v.25 no.2
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• pp.207-218
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• 2015

Objective : The purpose of this study was to investigate the characteristics of Gam-ki (double-arm winding) depending on the emotion being expressed. Gam-ki is one of the basic movements of Korean traditional dance. Method : We selected three Korean traditional dancers who belong to National Dance Company of Korea. They were asked to express four different emotions (anger, joy, sadness, and neutral) while performing Gam-ki. We analyzed elapsed time and time ratio, size of movement, ground reaction forces and ground impulses. Results : During Gam-ki the elapsed time for each phase as well as for one cycle was longest when "sadness" was expressed then followed by "neutral" and then "angry" and "joy." Except for the ankle in/eversion, the ROMs of the lower limb joints seem not to be an emotion-characteristic factor. The ROMs of the upper limb joints were largest when "anger" was expressed. Neck rotation is associated with expressing negative emotions ("angry" and "sadness"). For medial-lateral GRF "angry"> "joy" > "neutral" > "sadness" was in order. Therefore, it can be regarded as a factor indicating the activity of the emotion.