• Journal of Biomedical Engineering Research
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• v.30 no.2
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• pp.142-146
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• 2009

The purpose of this study is to investigate the angular velocity of forearm pronation/supination movement in Parkinson's disease patients, as a quantitative measure of the bradykinesia. Thirteen Parkinson's disease patients ($64{\pm}11.0$ yrs, male:6, female:7) participated in the experiments. The subjects' both right and left forearms were scored by a rater according to rapid alternating movement of hands category in the UPDRS (unified Parkinson's disease rating scale) and the angular velocity of forearm pronation/supination was measured at the same time. As analysis parameters, RMS (root mean square) angular velocity and RMS angle were used. The parameters showed negative correlation with the clinical score (RMS angular velocity: r= - 0.914, RMS angle: r= -0.749). The RMS angular velocity of all clinical scales were significantly different one another except for the non significant difference between those of scale 3 and 4. RMS angle of scale 0 was significantly different from those of scale 2, 3, 4 and that of scale 1 was significantly different from those of scale 3 and 4. This suggests that RMS angular velocity can be used for a quantitative measure of bradykinesia in motor examination.

• Korean Journal of Computational Design and Engineering
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• v.17 no.3
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• pp.149-155
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• 2012

The ankle over-pronation causes the mechanical overloading transferred to proximal areas (i.e. knees or hips) over time. Thus, the over-pronation is recognized as a contributory factor in a wide variety of musculo-skeletal pathologies in lower extremities. Commonly, over-pronated ankles are treated using specially designed insoles that support medial heels and correct the posture of lower limbs. However, the biomechanical effects of the insoles are not yet fully understood, so there still are controversies whether such insoles really have clinical significance. In this study, in order to verify the effects of insoles and determine the best shape of the insoles, we examined how the medio-lateral knee joint reaction force changes due to insole conditions through a case study about a subject. As a result, it is revealed that the medial heel post, which drastically reduced the peak medio-lateral knee joint reaction force, has significant effects on the gait of the over-pronated patients. However, in case that the arch support is combined together, the positive effect of the medial heel post may rather decrease.

• Korean Journal of Applied Biomechanics
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• v.16 no.1
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• pp.65-79
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• 2006

The purpose of this study was firstly to investigate correctional function of custom semi-rigid foot orthotics for excessively pronated people during gait by observing comfort, navicular movement and leg muscles' activity according to short-term and mid-term wearing duration and secondly to understand positive and/or negative point of view of a recently proposed paradigm related to foot orthotics more profoundly. Sixteen subjects who showed excessive pronation at navicular drop test were recruited for this study. Custom semi-rigid foot orthotics were made fitting for foot characteristics of the subjects by podiatry division of Otto Bock Korea company. While wearing the foot orthotics for two months, comfort of wearing were questioned and vertical navicular movement and electromyography of leg muscles during gait were measured at the condition of both immediately after and 2 months after including a control condition, respectively. The subjects were required to walk on a treadmill at the speed of 1.5m/s and four digital video camera filmed the movement of navicular process at the speed of 60 frames/s. In conclusion, in excessively pronated group continuous increase of comfort from short-term to mid-term wearing of custom foot orthotics is assumed to be closely related with short-term and mid term correctional action, of which are consisted the decrease of the range of navicular drop and navicular raisins- the faster timing of minimum navicular position occurring, and the decrease of leg muscles' activities. This conclusion could lead to positively accept new paradigm related to foot orthotics suggested by Nigg and the author suggest that in the future study the variable which could observe navicular movement would be one of major variables to study preferred path of skeleton in the paradigm.

• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.405-411
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• 2013

Objective: Product design process without considering the strength of the user can cause the excessive burden on musculoskeletal system of human body. Since the muscle strength will vary depending on the body posture, the design of product should consider the characteristics of body posture. This study was performed to investigate the effects of forearm postures on the push and pull strength. Background: Overexerted force has been identified to cause musculoskeletal disorders. It is important to know the push and pull strength exerted by human when designing so that exerted force does not exceed the safety limits. Method: Maximum isometric push and pull strength of left, right and both hands were measured according to forearm postures with pronation, neutral and supination. For the study, 66 male and 30 female undergraduate students were participated as subjects. All subjects were normal and healthy with no clinical history. Results: The results showed that the push strength of male and female were 93.3% and 85.4% of pull strength. It showed that the strength of one-hand was 72.1~81.0% of the strength of two-hands, and the strength of left hand was 93.1~95.8% of the strength of right hand. The strength of female was 62% of the one of male. It was found that the strength with pronation $90^{\circ}$ was reduced up to 20% compared to the strength with neutral posture. Conclusion: Push and pull strength of male and female were reduced when forearm was rotated extremely. Application: The results of this study will be used for the prevention of work related musculoskeletal disorders and design of industrial equipment.

• PNF and Movement
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• v.19 no.1
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• pp.147-152
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• 2021

Purpose: This study was conducted to investigate the functional differences of the two heads of the biceps brachii by measuring the functions in supination according to pronation by the angle of the flexion of the elbow joint, except for the activities of the elbow flexors. Methods: This study was conducted with 25 healthy men in their 20s. At a glenohumeral-joint 0˚ flexion posture, angles of flexion of the elbow joint of 0˚, 30˚, 60˚, 90˚, and 120˚ were randomly provided, and they were asked to perform supination and pronation with an elastic band. Using an eight-channel surface electromyogram, the muscle activities of the long and short heads of the biceps brachii were measured. The activities of the short and long heads according to the angle were analyzed using a one-way ANOVA, and as a post-test, LSD was employed. Results: The analysis of the impact of the resistance of the elastic band in supination on the differences in the muscle activities in the short and long heads suggests there was a significant difference between 0˚ and 30˚ (p < 0.05). Conclusion: In supination according to forearm pronation, the long head had greater action in the early flexion posture of the elbow joint, and it is judged that the ratio of the flexion of the elbow joint according to the actions of the biceps brachii was considered small.

• PNF and Movement
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• v.21 no.1
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• pp.19-25
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• 2023

Purpose: The aim of this study is to determine the effects of gastrocnemius stretching with talus-stabilizing taping on ankle dorsiflexion and subtalar joint pronation during walking. Methods: In total, 26 subjects with limited ankle dorsiflexion were equally divided into two groups: a gastrocnemius stretching with talus-stabilizing taping group (13 subjects) and a gastrocnemius stretching group (13 subjects). They were assessed according to ankle dorsiflexion and subtalar joint pronation during walking before and after an intervention, which involved two types of gastrocnemius stretches performed three times a week for six weeks. Results: Ankle dorsiflexion was significantly increased in both groups (p<0.05), though the gastrocnemius stretching with talus-stabilizing taping group showed a significantly greater improvement in ankle dorsiflexion than the gastrocnemius stretching group (p<0.05). However, subtalar joint pronation showed no difference between the two groups before and after (p>0.05), also between groups (p>0.05). Conclusion: Gastrocnemius stretching with talus-stabilizing taping is a useful stretching exercise that improves ankle dorsiflexion during walking in subjects with limited ankle dorsiflexion movement.

• PNF and Movement
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• v.21 no.1
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• pp.139-146
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• 2023

Purpose: The aim of this study is to provide basic information to create an efficient training program to improve shoulder stability and function in patients with injuries and in patients having undergone surgery of the supraspinatus and infraspinatus muscles, which have a relatively high incidence of injury in shoulder joint disease. Further, independent activities of the supraspinatus and infraspinatus muscles were investigated according to forearm rotation and the neutral and lateral rotation postures. Methods: The activities of the supraspinatus and infraspinatus muscles were measured using surface electromyography in 22 healthy adults in Busan, and isokinetic muscle strength measurement equipment was used to measure muscle strength during shoulder lateral rotation. The subjects performed lateral rotation of the shoulder in three different forearm postures (neutral, supine, prone) to measure shoulder muscle activity and lateral rotation strength. Results: The independent activity ratio (% Isolation) of the supraspinatus and infraspinatus muscles during lateral rotation of the shoulder joint demonstrated a significant difference (p<0.05) according to the change in forearm posture. Conclusion: The supraspinatus muscle showed independent activity ranging from highest to lowest in the order of pronation, neutral, and supination of the forearm, while the independent activity of the infraspinatus muscle ranged from highest to lowest in the order of neutral, supination, and pronation of the forearm. Therefore, the most active forearm positions for the supraspinatus and infraspinatus muscles are pronation and neutral, respectively.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.83-98
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• 2004

The purpose of this study was to investigate the test-retest of plantar pressures using the F-Scan system over speeds and plantar regions. 6 healthy female subjects in 20's were recruited for the study. Plantar pressure measurements during locomotor activities can provide information concerning foot function, particularly if the timing and magnitude of the loading profile can be related to the location of specific foot structures such as the metatarsal heads. The Tekscan F-Scan system consists of a flexible, 0.18mm thick sole-shape having 1260 pressure sensors, the sensor insole was trimmed to fit the subjects' right. left shoes - sneakers shoes & dress shoes. It was calibrated by the known weight of the test subject standing on one foot. The Tekscan measurements show the insole pressure distribution as a function of the time. This finding has important implications for the development of plantar pressure test protocols where the function of the forefoot is important. According to the result of analysis it is as follows 1) Center of force trajectory in women's dress shoes display direct movement, compare with center of force trajectory in Sneaker shoes displays a little bit curved slow pronation movement. Sneaker shoes in forefoot part display very quick supination movement, therefore, this shoes effects negative effectiveness for ankle's stability Considering center of force trajectory analyzing the more center of force close straight line, the more movement can be quick movement for locomotion. For foot pressure distribution, center of force trajectory in locomotion is better to curved trajectory with pronation movement. So sneaker shoes style is good shoes considering center of pressure distribution trajectory compare with women's dress shoes. 2) Women's dress shoes increased peak pressure in medial, this is effected by high hill's height. The more increased women's dress shoes's height, the more women's peak pressure will increase, pronation can increase compare with before. Supination movement increase, this focused pressure in lateral, also, supination increased more. If the supination movement increased, foot pressure focused in lateral, therefore, it is appeared force distribution in gait direction. This is bad movement in foot's stability. 3) Women's dress shoes in landing phase displayed a long time, this is when women's dress shoes wear, gait movement is unbalance, so, landing phase displayed a long time. For compensation in gait, swing phase quick movement. 4) Women's dress shoes displayed peak pressure distribution in lateral of rearfoot part, Sneakers shoes displayed peak pressure distribution in medial of forefoot part. Its results has good impact absorption compare with women's dress shoes. In forefoot part, sneakers shoes has good propulsive force compare with women's dress shoes.

• The Journal of Korean Physical Therapy
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• v.25 no.6
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• pp.411-416
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• 2013

Purpose: The purpose of the present study was to determine the effects of activation of gluteus maximus (Gmax) and abdominal muscle using EMG biofeedback on lumbosacral and tibiocalcaneal angles in standing position. Methods: Fourteen healthy subjects with normal feet participated in the present study. Electromyographic (EMG) biofeedback using visual cue was used to activate the external oblique (EO) and Gmax. The lumbosacral and tibiocalcalcaneal angles were measured by electronic goniometers. All the subjects were instructed to activate the Gmax and EO monitoring increasing amounts of the muscle activities in each muscle. The lumbosacral and tibiocalcaneal angles were collected in three trials during resting and activation of each muscle using EMG biofeedback in standing position. The mean value of three trials was used in the data analysis. A paired-t test was used to compare the lumbosacral and tibiocalcaneal angles between resting and activation of the Gmax and EO using EMG biofeedback. Results: The lumbosacral and tibiocalcaneal angles were significantly less in the resting compared to activation using EMG biofeedback (p<0.05). Conclusion: The activaition of Gmax and abdominal muscles using EMG biofeedback play role to control the pronation of subtalar joint during the weight-bearing.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.19 no.2
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• pp.19-22
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• 2013

Background: Excessive pronation of the feet can cause excessive inner rotation of the femur, followed by increased stress in the gluteus maximum, increased front slope of the pelvis, and lumbar lordosis, which leads to lumbar pain. The aim of the present study was to use the navicular drop test to examine foot pronation that can cause lumbar lordosis and to determine whether the navicular drop is lower in patients diagnosed with lumbar disc than in patients without this diagnosis. Methods: The Navicular Drop score was set by subtracting the navicular height at a standing position from the navicular height in a sitting position. The Navicular Drop measurements for college student with and without Lumbar Herniated Intervertebral Disc were compared using an independent t-test. Results: The control group were measured right $7.44{\pm}2.96$ and left $8.04{\pm}3.23$. The experimental group were measured right $2.12{\pm}1.33$ and left $2.80{\pm}1.29$. Therefore significant difference was found between the two groups (p<0.05). Conclusions: The navicular drop affected lumbar herniated intervertebral disc.