• Physical Therapy Korea
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• v.7 no.2
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• pp.88-95
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• 2000

Thirty normal adults were tested to measure the electrical activity of the anterior (AD), middle (MD), and posterior portion (PD) of the deltoid muscle and sternal portion of the pectoralis major muscle (PM) during the performance of four upper extremity PNF diagonal patterns with elbow flexion angle in $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$. The PNF patterns in which these muscles function optimally have been theoretically advanced by Kabat and further described by Knott and Voss. They theorize that the MD should be most active with shoulder flexion, abduction, and external rotation (D2F); the PD with shoulder extension, abduction, and internal rotation (D1E); the AD with shoulder flexion, adduction, and external rotation (D1F); and the PM with shoulder extension, adduction and internal rotation (D2E). The patterns were performed through range of motion, with an isometric contraction performed in the shortened range. When the EMG activity of AD, MD, PD and PM in its optimal patterns was measured, it does not have significant difference among fixed elbow flexion angle $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$ (p>.05). In addition, suggestions were made for study of patients who exhibit imbalance of muscle strength and have muscle weakness.

• Clinics in Shoulder and Elbow
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• v.26 no.2
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• pp.126-130
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• 2023

Background: Arm swing plays a role in gait by accommodating forward movement through trunk balance. This study evaluates the biomechanical characteristics of arm swing during gait. Methods: The study performed computational musculoskeletal modeling based on motion tracking in 15 participants without musculoskeletal or gait disorder. A three-dimensional (3D) motion tracking system using three Azure Kinect (Microsoft) modules was used to obtain information in the 3D location of shoulder and elbow joints. Computational modeling using AnyBody Modeling System was performed to calculate the joint moment and range of motion (ROM) during arm swing. Results: Mean ROM of the dominant elbow was 29.7°±10.2° and 14.2°±3.2° in flexion-extension and pronation-supination, respectively. Mean joint moment of the dominant elbow was 56.4±12.7 Nm, 25.6±5.2 Nm, and 19.8±4.6 Nm in flexion-extension, rotation, and abduction-adduction, respectively. Conclusions: The elbow bears the load created by gravity and muscle contracture in dynamic arm swing movement.

• The Journal of Korean Physical Therapy
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• v.35 no.1
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• pp.13-18
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• 2023

Purpose: The purpose of this study was to investigate the effects of posterior oblique sling activation on the muscle activities of the gluteus maximus (GM), multifidus (MF), and biceps femoris (BF) during three different prone hip extension exercises in healthy male individuals. Methods: Twenty healthy subjects participated in this study. An electromyography device was used to measure the muscle activities of the GM, MF, and BF. Each subject was asked to perform three different prone hip extensions as follows: [1) Prone hip extension with knee flexion + hip abduction 30°; PHE1, 2) Prone hip extension with knee flexion + hip abduction 30° and shoulder abduction 125°; PHE2, 3) Prone hip extension with knee flexion + hip abduction 30° and shoulder abduction 125° with 1kg loading; PHE3, in random order. A one-way repeated measures analysis of the variance and a Bonferroni post hoc test were used to analyze the results. The statistical significance was set at α=0.01. Results: The muscle activity of the GM was significantly different between the three positions (P_adj<0.01). The muscle activity of the GM was significantly greater during PHE3 compared with PHE1 and PHE2 (P_adj<0.01). The BF muscle activity was significantly lower during PHE3 compared with PHE1 and PHE2 (P_adj< 0.01). There was no significant difference in the muscle activity of the MF (P_adj<0.01). The ratio of the muscle activity (ratio=GM/BF) during PHE3 was significantly greater compared to PHE1 and PHE2 (P_adj< 0.01). Conclusion: The GM activity and GM/BF ratio during the PHE3 exercise were significantly greater compared to that during PHE1 and PHE2. Therefore, the PHE3 exercise could be recommended as a selectively effective GM activation exercise while decreasing the muscle activity of the BF.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.8
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• pp.505-510
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• 2017

This paper presents a low-cost robotic device for shoulder rehabilitation, which is capable of treating various shoulder disabilities. A 3-DOF passive shoulder joint tracking module was designed to allow for translational motion of the shoulder joint center during arm swing, which is essential for natural shoulder movement. The weight of the user's arm and the device were compensated for by springs, to enable gravity-free shoulder motion. In order to reduce the device's cost, only one actuator was used, which can be aligned with the user's shoulder joint in various orientations. The device is capable of implementing five representative shoulder motions, including flexion/extension, abduction/adduction, horizontal abd/adduction, internal/external rotation, and oblique raise. The proposed low-cost shoulder rehabilitation robot is expected to provide effective rehabilitation for patients with various shoulder impairments.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.85-95
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• 2005

The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle during One Hand Backhand Stroke and Two Hand Backhand in tennis. For the movement analysis three dimensional cinematographical method(APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVIEW 6.1 graphical programming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and racket head direction were defined. 1. In three dimensional maximum linear velocity of racket head the X axis and Y axis(horizontal direction) showed $-11.04{\pm}2.69m/sec$, $-9.31{\pm}0.49m/sec$ before impact, the z axis(vertical direction) maximum linear velocity of racket head did not show at impact but after impact this will resulted influence upon hitting ball. It could be suggest that Y axis velocity of racket head influence on ball direction and z axis velocity influence on ball spin after impact. The stance distance between right foot and left foot was mean $75.4{\pm}5.86cm$ during one hand backhand stroke and $72.6{\pm}4.67cm$ during two hand backhand stroke. 2. The three dimensional anatomical angular displacement of trunk in interna rotation-external rotation showed most important role in backhand stroke. and is follwed by flexion-extension. the three dimensional anatomical angular displacement of trunk did not show significant difference between one hand backhand stroke and two hand backhand stroke but the three dimensional anatomical angular displacement of trunk was bigger than one hand backhand stroke. 3. while backhand stroke, the flexion-extension and adduction-abduction of right shoulder joint showed significant different between one hand backhand stroke and two hand backhand stroke. the three dimensional anatomical angular displacement of right shoulder joint showed more flex and abduct in one hand backhand stroke. 4. The three dimensional anatomical angular displacement of left shoulder showed flexion, adduction, and external rotation at impact. after impact, The angular displacement as adduction-abduction of left shoulder changed motion direction as abduction. angular displacement of left shoulder as flexion-extension showed bigger than the right shoulder.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.8
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• pp.769-776
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• 2007

This paper proposes the human arm motion tracking algorithm based on the signal processing for surface EMG (electromyogram) sensors attached on both upper arm and shoulder. The signals acquired by using surface EMG sensors are processed with choosing the maximum in a short period, taking the absolute value, and filtering noises out with a low-pass filter. The processed signals are directly used for the motion generation of virtual arm in real time simulator. The virtual arm of simulator has two degrees of freedom and complies with the flexion and extension motions of elbow and shoulder. Also, we show the validity of the suggested algorithms through the experiments.

• Journal of the Korean Society of Physical Medicine
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• v.2 no.1
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• pp.11-20
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• 2007

Purpose : The purpose of this study was to evaluate effects of shoulder girdle stability exercise on upper extremity muscle strength. Methods : Subjects were consist of 20 people who had no disorder of upper extremity from 20 to 27 years of age during 6 weeks from April 3, 2006 to May 14. Ten of all subjects exercised muscles which stabilize to shoulder girdle for 30 minutes during 6 weeks. Biodex was used to measure upper extremity muscle strength. Results : There are increasing of shoulder flexion and extension on average torque but no statistically significant difference between pre-exercise and post-exercise. Conclusion : There are no severe difference between exercise group and non-exercise group on muscle strength.

• PNF and Movement
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• v.10 no.1
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• pp.9-17
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• 2012

Purpose : This study's purpose is consideration about change of the hand grip strength according to different posture and shoulder flexion angle. The shoulder joint permits the greatest mobility and carries out the important function of stabilization for hand use. Hand grip activity is important to evaluate while assessing loads of shoulder in hand mobilities. Methods : Thirty(15 male, 15 female) college students with unknown shoulder dysfunction participated subject in five different positions of elbow extension with sitting and standing posture, different positions is followed : (1) shoulder $0^{\circ}$ flexion (2) shoulder $45^{\circ}$ flexion (3) shoulder $90^{\circ}$ flexion (4) shoulder $135^{\circ}$ flexion (5) shoulder $180^{\circ}$ flexion. Results : On the average, in the hand grip strength, the standing posture is higher than sitting posture. Sitting posture showed a most high level at the man's $0^{\circ}$ and woman's $135^{\circ}$. And standing posture showed a most high level at the man's $135^{\circ}$ and woman's $90^{\circ}$. Conclusion : The paired t-test was used to determine the different in grip strength between sitting and standing posture by shoulder angle change. There was no significant difference between the five position by sitting and standing posture. In man, correlation analysis revealed significant connection for all five position by sitting and standing posture. And in woman, correlation analysis revealed connection for all five position by sitting and standing posture.

• Clinical Pain
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• v.19 no.2
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• pp.124-128
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• 2020

Motor paralysis is a less common neurologic complication of herpes zoster. Until now, a few cases have been reported, and most of these cases showed brachial plexopathy involving one or two segments. We report a patient with pain and weakness on upper extremity diagnosed as brachial plexopathy after herpes zoster infection. An 88-year-old female patient complained not only tingling sense, pain, and swelling on right whole arm, but also weakness on this right upper extremity. On physical examination, weakness is seen in right shoulder abduction·shoulder flexion·elbow flexion·elbow extension· wrist extension (grade 4), finger flexion·finger abduction·finger extension·finger DIP flexion (grade 3). In electrodiagnostic study and magnetic resonance imaging study, she was diagnosed as the brachial plexopathy, whole branch involved. This is the only case of post-herpetic brachial plexopathy involving whole branch in domestic.

• Journal of the Korean Orthopaedic Association
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• v.55 no.5
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• pp.426-430
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• 2020

Magnetic resonance imaging and static ultrasound imaging do not indicate some cases of partial thickness tears of the supraspinatus tendon. The authors observed a partial thickness tear of the supraspinatus tendon that was not found using other imaging tools but was observed by resisted scaption in shoulder extension position dynamic ultrasound in several cases. This paper outlines this technique is reported by describing two cases.