• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.83-94
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• 2012

The purpose of this study was to analyse the effect of posture correction & stabilization according to horse rider's(n=10) skill levels of novice(0wk), mid-skill(12wk) & skill(24wk) in walk & trot. First, Mean posture of 3 times experiments; Anterior & posterior leaning posture of trunk showed rather unstable according to progress of the stages of TD1, TO, TD2 phase, and also shoulder & elbow angle, which effects to the distance from bit to rein, showed unstable riding posture. There was close relationship between shoulder and elbow Angle in walk and hip, knee & ankle angle in trot. Second, Posture correction & stabilization according to riding skill levels; Anterior & posterior leaning posture of trunk did not show significant difference statistically but showed approaching tendency to trunk's vertical line and showed significant difference(p<.05) according to improvement of skill levels in walk & trot horse riding. Hip angle showed significant difference according to progress of the stages of TD1, TO, TD2 phase(p<.05) and showed tendency maintaining the larger thigh flexion according to improvement of skill levels in walk & trot. Knee angle showed more stable posture by maintaining the larger flexion between thigh and shank according to improvement of skill levels in walk & trot(p<.05). Ankle angle also showed tendency maintaining the larger plantar flexion of foot according to improvement of skill levels in walk & trot. When considering the above, regular horse riding program could be useful in posture correction & stabilization according to improvement of skill levels of novice(0wk), mid-skill(12wk) & skill(24wk) in walk & trot.

• PNF and Movement
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• v.17 no.3
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• pp.471-480
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• 2019

Purpose: This study examined the correlations between a forward head posture and the endurance and maximal voluntary contraction of the deep neck flexor, neck pain, and the changed position of the mandible. Methods: The subjects of this study were 50 male and female adults who work at a desk for at least four hours a day. The head-spine angle was photographed with a camera, and the endurance and maximal voluntary contraction of the deep neck flexor and the changed position of the mandible were measured using pressure biofeedback. The Neck Disability Index was used to measure neck pain. To examine the correlations between a forward head posture and the endurance and maximal voluntary contraction of the deep neck flexor as well as the changed position of the mandible, a Spearman's correlation analysis was conducted. The statistical significance was set at 0.05. Results: A forward head posture and the endurance of the deep neck flexor showed a statistically significant positive correlation, and a forward head posture and neck pain showed a statistically significant negative correlation. In addition, the endurance of the deep neck flexor and neck pain showed a statistically significant negative correlation. Conclusion: The results of this study show that a forward head posture and the endurance of the deep neck flexor were correlated; in addition, a forward head posture and neck pain were correlated. Therefore, enhancing the endurance of the deep neck flexor can assist in correcting an imbalanced forward head posture, which can reduce neck pain.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.191-203
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• 2005

It was to study a following research of "A Kinematical Traits Analysis when Performing Uchimata(inner thigh reaping throw) by Posture and Voluntary Resistance Levels(VRL) of Uke in Judo[1]" and. "A Case Study of Center of Gravity(COG) when Performing Uchimata(inner thigh reaping throw) by Posture and Voluntary Resistance Levels(VRL) of Uke in Judo[II]". The purpose of this study was to analyze an angular momentum of trunk and lower extremity when performing uchimata by two postures and voluntary resistance levels(VRL) of uke(reciver) in Judo. The subjects, who were one male judoka(YH) for 1992 Barcelona Olympic Games Olympian(silver medalist), was filmed on two S-VHS 16mm video cameras(60fields/sec.) through 3-dimensional motion analysis methods, that postures of uke were shizenhontai (straight natural posture:NP) and jigohontai (straight defensive posture:DP), VRL of uke were 0% and 100%, respectively. The variables were angular momentum of trunk, lower extremity of attacking leg and supporting leg of tori(the thrower). The data of this study collection were digitized by SIMI Motion Program computed the mean values and the standard deviation calculated for each variables. When performing uchimata according to each posture and VRL of uke and classifying. From the data analysis and discussion, the conclusions were as follows : Angular momentum of trunk when performing uchimata was showed the largest among another angular momenta, and the posture displayed more different than resistant of uke(reciver), but the pattern similar in judo. Angular momentum of trunk of X axis was the largest and Y, Z axis order. Angular momentum of attacking the thigh-leg when performing uchimata was showed the largest among another angular momenta, and the posture displayed more different than resistant of uke(reciver), X axis and Y axis similar, but angular momentum of Z axis of thigh-leg the largest, in kake(application) event in 0% resistance of DP than other variables. Angular momentum in X,Y axis of attacking the lower-leg when performing uchimata was showed that the resistance level displayed more different than posture, but Z axis the largest, in kake(E3) phase in 0% resistance of DP than other variables as same thigh-leg, and the largest from tsukuri(set-up:E2) to kake(E3) phase. X and Z axis Angular momentum of supporting the thigh-leg were similar, regardless of posture and resistance of uke, but Y axis was resistance level. Angular momentum of supporting the thigh-leg was showed the largest in X axis, increased from EO event to E2, and decreased in E3, and angular momenta of Y, X axis were showed the largest in kuzushi(balance breaking) phase when performing uchimata. Angular momentum of supporting the lower leg were similar pattern, regardless of posture and resistance of uke, in Y axis, resistance displayed more difficult the position in NP, and showed opposite angular momentum in tsukuri phase. In conclusion, angular momentum of trunk when performing uchimata was showed the largest, and pattern was similar, regardless of posture than resistant of uke(reciver), magnitude and direction were different each other, and uchimata was Ashi -waza(foot and leg techniques) division but important of trunk action.

• Journal of the Ergonomics Society of Korea
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• v.26 no.1
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• pp.29-37
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• 2007

This study was performed to evaluate the characteristics of transmitted vibration to hand-arm system under different work posture while operating a light-weighted powered hand grinder. For the experiment, 8 different types of wrist posture (natural, unlar-flexion, radual-flexion, flexion, extension, complex posture, and etc.) and 3 types of feed force (20[N], 50[N], 70[N]) were considered. 10 male subjects were employed to polish metal plate with a hand grinder. All of them were normal and healthy with no history and symptom of the work related musculoskeletal disorders in the dominant hand. Vibration acceleration data were recorded with sampling rate, 2048[Hz]. In addition, unweighted overall R.M.S. acceleration at the tool and wrist, and transmissibility between them were used to evaluate factors from the recorded tri-axial vibration acceleration. The results indicate that transmissibility of natural wrist posture was significantly higher than others. In addition, as the feed force becomes larger, the vibration was transmitted in large quantities to hand-arm system through radius.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.1
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• pp.85-92
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• 2017

Purpose : The purpose of this study was to investigate the effect of posture difference on respiratory function in cerebral palsy patients. Methods : Twenty-two cerebral palsy childrens were recruited this study. Respiratory Function test was measured with Cardio Touch 3000 and Micro Respiratory Pressure Meter. Cardio Touch 3000 was used to assess cerebral palsy childrens' forced vital capacity and forced expiratory volume at one second. Micro Respiratory Pressure Meter was to assess Maximum inspiratory pressure and Maximum expiratory pressure. Subjects had four respiratory functions measured in supine, slouched sitting, and elected sitting postures. Statistical analysis was used Paired t-test for within-group comparisons and Independent t-test for between-group comparisons. SPSS statistics Ver 20.0 was used for statistical anlysis and statistical significance was defined as a p-value less than 0.05. Result : The subjects' respiratory function according to posture showed significant difference in Forced Vital Capacity(FVC), Maximum Expiratory Pressure(MEP) and Maximum inspiratory pressure(MIP)(p<.05). Elected sitting posture had a positive effect on respiratory function than slouched sitting, supine. Conclusion : In conclusion, We could see that change of posture in children with cerebral palsy affects respiratory function and Elected sitting can be a positive help for the respiratory function of children with cerebral palsy.

• Journal of the Ergonomics Society of Korea
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• v.27 no.1
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• pp.53-60
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• 2008

The purpose of this study is to provide basic data, such as exerting muscle power of the lower-extremity, EMG test and pressure distribution for designing ergonomic workstation in sitting posture. The exerting muscle power of the lower-extremity was measured by PRIMUS in 4 postures of 90$^{\circ}$, 120$^{\circ}$, 150$^{\circ}$ and 180$^{\circ}$. And performed ANOVA test on Max. and Mean 100%MVC. In EMG test for surveying muscle mobiligation, 5 muscles(Rectus Femoris, Vastus Lateralis, Gastrocnemius, Soleus, Tibialis Anterior) were employed. Additional experiment in pressure distribution in sitting posture by Pliance(16$\time$16 poles), Max. pressure was measured and performed ANOVA test on the results. Concludingly, sitting posture with 120$^{\circ}$ lower-extremity is the best design criterion for ergonomic workstation in sitting posture.

• Journal of Auto-vehicle Safety Association
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• v.12 no.1
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• pp.52-61
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• 2020

In recent years, the increasing interest in health-care requires the industrial products to be well-designed ergonomically. In the commercial vehicle industry, several researchers have demonstrated the driver's posture has great effect on the orthopedic desease such as fatigue, back pain, scoliosis, and so on. However, the existing sensor systems developed for measuring the driver posture in real time have suffered from inaccuracy and low reliability issues. Here, we suggest our smart vehicle seat system capable of real-time driver posture monitoring by using the air bag sensor package with high sensitivity and reliability. The ergonomic numerical model which can evaluate a driver's posture has been developed on the basis of the human body segmentation method followed by simulation-based validation. Our experimental analysis of obtained pressure distribution of a vehicle seat under the different driver's postures revealed our smart vehicle system successfully achieved the driver's real-time posture data in great agreement with our numerical model.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.3
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• pp.7-16
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• 2011

This study proposes the compensation method for the mechanical deflection error of a SCARA robot. While most studies on the related subject have dealt with the development of a control algorithm for improvement of robot accuracy, this study presents the control method reflecting the mechanical deflection error which is predicted in advance. The deflection at the end of the gripper of SCARA robot is caused by the self-weights and payloads of Arm 1, Arm 2 and quill. If the deflection is constant even though robot's posture and payload vary, there may not be a big problem on robot accuracy because repetitive accuracy, that is relative accuracy, is more important than absolute accuracy in robot. The deflection in the end of the gripper varies as robot's posture and payload change. That's why the moments $M_x$, $M_y$ and $M_z$ working on every joint of a robot vary with robot's posture and payload size. This study suggests the compensation method which predicts the deflection in advance with the variations in robot's posture and payload using neural network. To do this, I chose the posture of robot and the payloads at random, found the deflections by the FEM analysis, and then on the basis of this data, made compensation possible by predicting deflections in advance successively with the variations in robot's posture and payload through neural network learning.

• PNF and Movement
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• v.19 no.2
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• pp.163-172
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• 2021

Purpose: This study investigated the correlation between physical function and forward head posture in spastic diplegia. Methods: The subjects of this study were 10 spastic diplegia patients. We took pictures of the subjects' craniovertebral angle with a digital camera to determine the degree of forward head posture and then analyzed them using the NIH image J program. The physical function test used the TCMS, the BBT, and a spirometer. The data in this study were measured using SPSS version 23.0, and the statistical significance level α was 0.05. A Pearson correlation coefficient analysis was performed to identify the correlation between the degree of the subject's head forward position and physical function. Results: When we performed the BBT and spirometer tests, the subjects' forward head postures were not correlated (p < 0.05). However, with the TCMS, there was a strong correlation between the forward position of the head and balance, with balance decreasing as the head position increased (p < 0.05). Conclusion: Spastic diplegia patients with severe forward head posture showed problems with static balance, dynamic balance, and equilibrium reaction when sitting. Intervention on the right posture and preventive activities will be needed to improve the health of spastic diplegia patients and prevent future problems with physical function.

• The Journal of Korean Physical Therapy
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• v.35 no.3
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• pp.83-88
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• 2023

Purpose: This study was to investigate the effect of forward head posture (FHP) and round shoulder posture (RSP) on changes in muscle activities according to shoulder flexion and abduction tasks. Methods: Twenty-two male subjects with no history of neurological, musculoskeletal surgery or injuries, or pain in the spine region within the previous 3-month periods were recruited for this study. Craniovertebral angle (CVA) and Scapula Index were measured before performing 90° abduction and flexion tasks holding a 3kg dumbbell. Muscle activities were measured during the tasks. All measurements except height of the acromion were carried out in a sitting position at the height of the subject's knee angle of 90 degrees, and two tasks were randomly performed with the arm that the subject mainly use to throw the ball. The abduction and flexion angles were checked by the examiner using a goniometer beside the subject. Results: Correlation coefficient analysis between Scapular Index and upper trapezius muscle activity during shoulder abduction task showed significant positive correlation. No significant correlation was observed between CVA, Scapular Index, and other muscle activities. Conclusion: FHP showed increased muscle activation, making it difficult to change muscle activity under lower loads, and RSP was correlated with UT activation in shoulder abduction. Therefore, in the RSP, the loaded shoulder abduction is considered a potential risk factor for increasing shoulder muscle tension. This paper proposes an approach to treating RSP before FHP.