• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.5
• /
• pp.577-584
• /
• 1999

In this paper, the double inverted pendulum having a single actuator is built and the controller for the system is proposed. The lower link of the target pendulum system is hinged on the plate to free for rotation in the specified range($10^{\cire}$) on the x-z plane. The upper link is connected to the lower link through a DC motor. The double inverted pendulum built can be kept upright posture by controlling the position of the upper link even though it has no actuator in lower hinge. The algorithm to control the inverted pendulum consists of a state feedback controller within a linearizable range and a fuzzy logic controller coupled with a nonlinear feedback compensator for the rest of the range. Conventional state feedback control is employed, and the fuzzy controller is responsible for generating the reference joint angle of the upper link for the nonlinear feedback compensator which drives a DC motor to generate an indirect torque to the lower joint. As a result, we can get the upright posture of the proposed pendulum system. Simulations and experiments are conducted to show the validity of the proposed controller.

• The Journal of Korean Physical Therapy
• /
• v.31 no.3
• /
• pp.151-156
• /
• 2019

Purpose: This study aimed to investigate the immediate effects of posture correction and real-time visual feedback using a video display on muscle activity and change of head position during overhead arm lift test in individuals with forward head posture. Methods: Fifteen subjects with forward head posture and fifteen normal subjects who volunteered were included in this study. During both groups performed the overhead arm lift test, the muscle activity of the upper trapezius, serratus anterior, sternocleidomastoid, and lower trapezius muscle were measured using electromyography, and head position change was measured using photographs. Then, forward head posture group was asked to perform overhead arm lift test again after posture correction and real-time visual feedback using a video display respectively. One-way analysis of variance (ANOVA) was used to analyze four conditions: pre-test, posture correction, real-time visual feedback, and the control group. Results: The upper trapezius and lower trapezius muscle activity significantly decreased posture correction, real-time visual feedback, and control group than pre-test of forward head posture group (p<0.05). The sternocleidomastoid muscle significantly decreased real-time visual feedback and control group than pre-test of forward head posture group. Head position change significantly decreased three conditions than pre-test of forward head posture group and real-time visual feedback and control group significantly decreased than posture correction. Conclusion: This study recommend for maintaining cervical stability during the overhead arm lift test, postural control using real-time visual feedback is more effective in subjects with forward head posture.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.6 no.2
• /
• pp.55-62
• /
• 2012

In this paper we propose a control system to preserve the interior angle between back section and upper leg section to be larger than 90 degrees using a single limit switch. To design the control system we analyze the kinematics of actuation mechanisms for the back section and the upper leg section, and find out an optimal solution for the controller design. Using a prototype control system we perform experiments to test the controller performance, and show that the interior angle between the back section and the upper leg section is always preserved larger than 90 degree. From the experimental results, we show the proposed control system is feasible to keep the body posture stability.

• Journal of The Korean Society of Integrative Medicine
• /
• v.7 no.4
• /
• pp.301-309
• /
• 2019

Purpose : The purpose of this study was to provide an effective method of exercise therapy for patients with cervicogenic headache. Methods : The subjects were divided into the following two groups according to the intervention received: cervical stretch exercise (n=15, control group) cervix-stabilizing exercise (n=15, experimental group) tone (Hz) and stiffness (N/m) of the suboccipital and upper trapezius muscles were measured. T1 slope angle and neck tilt angle were measured. After the exercise program intervention, a greater amount of change in muscle tone and stiffness of suboccipital and upper trapezius muscles was found in the experimental group, as compared to the control group. Greater amount of change in posture was found in the experimental group, as compared to the control group (p<0.05). Results : After the exercise program intervention, a greater amount of change in muscle tone and stiffness of suboccipital and upper trapezius muscles was found in the experimental group, as compared to the control group. Greater amount of change in posture was found in the experimental group, as compared to the control group (p<0.05). Conclusion : The neck-stabilizing exercise were shown to be effective in decreasing the tone of the cervical muscles by stabilizing the cervical bone and improving muscle activity, and in improving the posture by decreasing muscle tone and stiffness.

• Proceedings of the KIEE Conference
• /
• 1998.07g
• /
• pp.2309-2311
• /
• 1998

The attitude control of a double inverted pendulum with a periodical disturbance at link top is dealt in this paper. The proposed system is consisted of the double inverted pendulum and a disturbance link. The lower link is hinged on the plate to free for rotation in the vertical plane. The upper link is connected to the lower link through a DC motor. The DC motor is used to control the posture of the pendulum by adjusting the position of the upper link. The periodical disturbance can be generated by the additional link attached at the end of link 2 through another DC motor, which is the modeling of a posture for a biped supporting with one leg. The motor for the joint simulates the knee joint(or hip joint) and the disturbance for the legs moving in air. The algorithm for controlling a proposed inverted pendulum is consisted of a state feedback control and a fuzzy logic controller. The fuzzy controller keeps the center of gravity of the biped within the specified range through the nonlinear feedback compensator. The state feedback control takes over the role to maintain a desired posture regardless the disturbance at the link top. In these case, the change of the angle and COG of an upper link is compensated with on-line. Simulations with a mathematical model are conducted to show the validity of the proposed controller.

• Journal of Convergence for Information Technology
• /
• v.7 no.5
• /
• pp.47-51
• /
• 2017

The purpose of this study was to investigate the effect of wearable sensor wear on the muscle contraction of cervical erector spinae and upper trapezius causing the forward head posture induction in order to reduce the stress induced by the use of smartphone. This study was to investigate the muscle activity of healthy adults in the 20th to 30th generations by dividing them into the control group using the smartphone, the non-wearing group conscious the posture of the head posture, and the wearing group wearing the wearable sensor. There were no differences in muscle activity between cervical erector spinae and upper trapezius compared to the control, non - wearing, and wearing groups. In addition, the changes in muscle activity of cervical erector spinae muscles were increased in all groups, but the muscle activity of upper trapezius muscles were in the wear group compared to the non-wear group and the control group, but there was no statistical significance. That is, wear of the wearable sensor may be effective in controlling the conscious posture, but it may cause the compensation of another part.

• Journal of the Korean Society of Physical Medicine
• /
• v.14 no.4
• /
• pp.81-91
• /
• 2019

PURPOSE: This study examined the effects of Kinesiology taping followed by pectoralis minor muscle self-stretching on the rounded shoulder posture, neck range of motion, and upper trapezius muscle tone in subjects with a rounded shoulder posture. METHODS: Thirty adults with a rounded shoulder posture were assigned randomly to one of two groups, either one that only performed pectoralis minor muscle self-stretching or a group that performed pectoralis minor muscle self-stretching after applying Kinesiology taping ; the subjects underwent four weeks of intervention. Three rounds of intervention were carried out over four weeks, and before and after the experiment, rounded shoulder posture, neck range of motion, and upper trapezius muscle tone creep were measured. RESULTS: Following the interventions, both the experimental and control groups showed significant improvement in the rounded shoulder posture, neck range of motion, upper trapezius muscle tone, stiffness, relaxation, and creep. Significant differences in the post training gains in the rounded shoulder posture and neck range of motion were observed between the experimental and control groups. CONCLUSION: These results showed that a combination of Kinesiology taping and pectoralis minor muscle self-s tretching led to more significant improvement than that seen when only utilizing the application of pectoralis minor muscle self-stretching to change the posture of the subjects with a rounded shoulder posture.

• International journal of advanced smart convergence
• /
• v.7 no.1
• /
• pp.33-41
• /
• 2018

This study was designed to provide basic data for developing exercise program that helps correcting posture by knowing the effect of strengthening and elongation exercises of upper extremity muscle to forward head posture correction. In this study determined subjects whether they had forward head posture or not. On the basis of the New York state posture rating, if a subject's posture is match up with the normal standard posture, gives 5 points and if the posture is slightly get out of the normal standard posture, gives 3 points and if the posture is apparently get out of the standard, gives 1 points. When determining the forward head posture, if talus, humerus and outer ear center are on the same line, it is determined as normal and if outer ear center is off the line less than 1.0cm, it is a slight deformation and if outer ear center is off the line more than 1.0cm, it is a high deformation. In the study selected people who have more than 1 cm gap between two vertical lines start from outer ear center and acromion separately as subjects. Length between the ideal alignment line measured by using goniometer and temporal region showed statistically significant decrease as $2.36{\pm}1.07cm$ before the intervention and $1.06{\pm}0.88cm$ after the intervention. After 4 weeks of neck and chest extensor muscle exercise, the group who exercised both showed increase in range of neck joint motion and neck flexion of the forward head posture. Meanwhile the group who only exercised neck extensor muscle only and the group who only exercised chest extensor muscle didn't showed statistically significant result. That only the group who exercised both muscles showed significant result is the different with studies before. Because this study didn't target patient who had a lesion, couldn't compare effect of the conservative manner and exercise. However, this study provides the fact that the group who exercised both neck and chest muscle had more effect than the control group.

• Journal of The Korean Society of Integrative Medicine
• /
• v.9 no.2
• /
• pp.93-103
• /
• 2021

Purpose : This study aimed to investigate the effect of trunk postural stability maintained wearing a spiral elastic band on the upper extremity function of patients with stroke who undertook a functional activity program and to provide fundamental data useful for the application of therapeutic interventions in the clinical environment of occupational therapy. Methods : The research subjects included 16 patients with stroke who were evenly divided into an experimental group and a control group. The eight-week intervention consisted of a functional activity program aimed at improving the function of the affected-side upper extremity. The experimental group performed the functional activity program while maintaining a stable trunk posture by wearing a spiral elastic band. The control group followed the program without wearing the band. Upper extremity function was assessed before and after the intervention using a manual function test (MFT) and a motor activity log (MAL), and the effectiveness on the upper extremity function of the affected side was confirmed. Results : First, in the within-group comparison of the upper extremity function scores before and after the intervention, the experimental group showed a statistically significant difference in the MFT and MAL assessment(p<.05). The control group showed a statistically significant difference in the MAL assessment(p<.05). Second, in the between-group comparison of the change in scores after the intervention, a statistically significant difference was observed between the two groups in all assessments(p<.05). Conclusion : This study confirmed the positive effect on upper extremity function of trunk stabilization posture using a spiral elastic band. The results could be useful when implementing a task-oriented training program in the clinical environment of occupational therapy in the future, as application of the training while maintaining trunk postural stability by wearing a spiral elastic band could be more effective for improving the upper extremity function of patients with stroke.

• Journal of the Korean Society of Physical Medicine
• /
• v.13 no.4
• /
• pp.149-162
• /
• 2018

PURPOSE: The aim of this study was to investigate the effect of scapular dynamic taping on pain, disability, upper body posture, and range of motion (ROM) in the postoperative shoulder. METHODS: Twenty-two patients who underwent acromioplasty and rotator cuff repair surgery volunteered for this study. The subjects were randomly divided into an experimental group (EG, n=11) and a control group (CG, n=11). For the EG, exercise therapy, manual therapy, and scapular dynamic taping were applied for 6 weeks; for the CG, only exercise therapy and manual therapy were applied for 6 weeks. Shoulder pain, disability, upper body posture, and ROM were evaluated at baseline, after 3 weeks of intervention, and after 6 weeks of intervention. Assessment tools included quadruple visual analog scale (QVAS) for level of pain; shoulder pain and disability index (SPADI) for functional disability level; forward head angle (FHA), forward shoulder angle (FSA), and pectoralis minor index (PMI) for upper body posture; and ROM testing. RESULTS: Significant differences were observed between the EG and CG in SPADI total scores; internal rotation and external rotation ROM of the glenohumeral joint ; FSA ; and PMI. All groups showed statistically significant improvement in QVAS; SPADI; flexion; abduction; external rotation and internal rotation ROM of the glenohumeral joint; FSA; and PMI. CONCLUSION: These results suggest that, for patients who have undergone acromioplasty and rotator cuff repair surgery, the addition of scapular dynamic taping during therapy is effective for improvement of shoulder disability level, ROM, and upper body posture.