• Journal of Korean Physical Therapy Science
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• 제26권3호
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• pp.8-14
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• 2019

Purpose: This study was conducted in order to influence the muscle strength of an serratus anterior, deltoid and triceps brachii depending on the left or right leg lifting during push up in the crawling position. Design: Cross-sectional study. Methods: 20 subjects participated in the study, Subjects perform 10 Push-up holding the right-left leg lifting in the crawling position according to the EMG sound that comes out every 3 seconds. Six muscles were measured in the right and left deltoid, triceps brachii and serratus anterior. Results: There was no significantly different in deltoid and triceps brachii activity in the lifted position compared to the unlifted position, but there was significantly difference in serratus anterior. Conclusion: In the crawling position, push up with the leg lifting increased the muscle activity of the serratus anterior Serratus anterior was higher than other muscle activity.

• The Journal of Korea Robotics Society
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• 제18권3호
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• pp.285-292
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• 2023

Small-scale ground mobile robots can access confined spaces where people or larger robots are unable. As the scale of the robot decreases, the relative size of the environment increases; therefore, maintaining the mobility of the small-scale robot is required. However, small-scale robots have limitations in using a large number of high-performance actuators, powerful computational devices, and a power source. Insects can effectively navigate various terrains in nature with their legged motion. Discrete contact with the ground and the foot enables creatures to traverse irregular surfaces. Inspired by the leg motion of the insect, researchers have developed small-scale robots and they implemented swing and lifting motions of the leg by designing leg linkages that can be adapted to small-scale robots. In this paper, we propose a leg linkage design for insect-inspired small-scale ground mobile robots. To use minimal actuation and reduce the control complexity, we designed a 1-DOF 3-dimensional leg linkage that can generate a proper leg trajectory using one continuous rotational input. We analyzed the kinematics of the proposed leg linkage to investigate the effect of link parameters on the foot trajectory.

• The Journal of the Korea Contents Association
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• 제9권12호
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• pp.665-673
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• 2009

This study was conducted to compare the PNF and Trunk Exercise Program has effectiveness on the pain, disability, static and dynamic balance in chronic low back pain patients. To evaluate the effects of exercise, subjects were evaluated by using VAS for pain, Oswestry disability index for disability, One leg stand test for static balance and Balance System for dynamic balance test. Pain, Oswestry disability index, One leg stand test, and Dynamic balance test in PNF had statistical significance than Trunk exercise program(p<0.05). So this results were suggested that the lifting and chopping pattern of PNF was effective on pain, disability and balance in chronic low back pain patients.

• Journal of the Korean Institute of Telematics and Electronics B
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• 제28B권11호
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• pp.886-896
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• 1991

In this paper a new turning gait is proposed for a quadruped walking robot. The proposed scheme makes it possible to control the translation and orientation of the walking robot simultaneously. At first the feasible leg sequences which can guarantee a positive longitudinal gait stability margin for each direction of movement are found. A method for finding the lifting time of each leg of a feasible leg sequince and selecting an optimal gait among feasible gaits is then suggested. The proposed gait can be appled to control the posture of walking robots and to generate an optimal gait for a desired movement of translation and rotation of the walking robot systematically.

• Physical Therapy Korea
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• 제8권1호
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• pp.76-88
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• 2001

Back extension exercises have been used for rehabilitation of the injured low back, prevention of injury, and fitness training programs. However, excessive loading on low back can exacerbate existing structural weakness. The purpose of this study was to compare muscle activity of low back muscles during back extension exercises. Twenty healthy male subject s were evaluated. Electromyographic (EMG) activities of low back muscles at L1 and L5 level were recorded during seven different back extension exercises and two reference tasks by surface EMG and saved for data analysis. Reference tasks of lifting 20% and 40% of their body weight were included for comparison. The result were as follows: 1) Single-arm extension and single-leg extension exercises on quadruped position appeared to constitute a low-risk exercise for initial extensor strengthening. 2) When arm extension was combined with contralateral leg extension on quadruped position, EMG activities of low back muscles were increased. 3) EMG activity of low back muscles was highest during the trunk extension exercises on prone position. 4) EMG activities of low back muscles during arm and leg extension exercises on quadruped position were less than those of reference task of lifting 40% of their body weight. These result s have important implications for progressive back extensor muscle strengthening exercises in patients with back pain.

• Physical Therapy Korea
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• 제12권1호
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• pp.1-10
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• 2005

The purpose of this study was to verify the most effective spinal stabilization exercises program by comparing the activities of muscles contributing to spinal stabilization during four types of exercises using a sling and a mat. Twenty healthy males were recruited and each subjects performed four types of exercises. Exercise 1 was performed in a quadruped position with the subjects lifting the left arm and the opposite leg on the mat. Exercise 2 was performed in a prone position while holding a sling with the right hand and the left knee was fully extended while lifting the left arm and right leg. Exercise 3 was performed in quadruped position while holding a sling with one the right hand and lifting the opposite arm and leg. In exercise 4, subjects were instructed to maintain a balance push-up position while holding slings with both hands in 10 cm forward reaching with extended elbows. Electromyographic(EMG) activities were recorded from the multifidus, external oblique, internal oblique, abdominal rectus, and erector spinalis muscles during the exercises. The EMG amplitude of each muscle was normalized to the amplitude in the maximal voluntary isometric contraction (MVIC) of each muscle. Repeated ANOVA and Bonferroni's tests were used to compare the differences in the muscle activity according to the types of exercise. The EMG amplitudes of all the muscles were significantly different according to the types of exercises (p<.05). The highest EMG activities of each muscle was as follow; multifidus was 73.38%MVIC in exercise 3, the erector spinalis was 40.03%MVIC in exercise 3, the external oblique was 135.88%MVIC in exercise 4, the internal oblique was 128.60%MVIC in exercise 4, and the rectus abdominalis was 95.24%MVIC in Exercise 4. The types of exercises showed a significant difference in composition rate of EMG amplitudes of each muscle (p<.05). EMG composition rate of the multifidus was high in exercise 1 and 3. However, EMG composition rates of the external oblique, internal oblique, and the rectus abdominals were high in exercise 2 and 4. These results showed differences in EMG activities of muscles contributing to trunk stabilization during different therapeutic exercises. Therefore, the type of exercise should be carefully selected to effectively strengthen a specific trunk stabilizer.

• The Journal of the Korea institute of electronic communication sciences
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• 제10권3호
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• pp.395-402
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• 2015

In this paper, we propose an efficient gait trajectory generation method for the static stair climbing of a quadruped robot with mechanism of insectile legs, which has no collision with staris. First, we derive the kinematic and inverse models of a quadruped robot using the algebraic and geometrical methods, respectively. In the proposed method, we generate the stair locomotion trajectory of a sine wave after lifting a leg from the start position, and then determine the coefficient of the generated trajectory to avoid the collision with stairs. In addition, we make the gait sequence for the stable stair locomotion. Finally, we verify the effectiveness and applicability of the proposed stair locomotion method through computer simulations.

• Korean Journal of Occupational Health Nursing
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• 제9권1호
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• pp.49-55
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• 2000

When standing, walking, or running for extended periods of time, fatigue occurs in the legs. Although there are many ways, to release tense or fatigued leg muscles, in the case that there is insufficient time to relax, an easy way to release leg fatigue is using an inclined step (about 3 minutes). This method was more effective than performing stretching exercises as studied. An experiment was conducted on a golf course in the Kangwon province in Korea. Subjects were chosen randomly and consisted of 5 females and 4 males golf caddies. Their main tasks consisted of pulling golf carts to the bottom of a hill for 8 to 10 hours and sometimes lifting and lowering golf clubs during the duration of one day. EMG was measured after work and after using the previously mentioned inclined Steps for the lower legs using ME3000P. This study investigated the types of inclined Steps which would be most effective and appropriate for golf caddies, whether sex difference had any influence existed between male and female workers. The results showed that a step with a $20^{\circ}$ angle was most effective for males and a step with a $25^{\circ}$ angle was most effective for females. Females showed faster recovery from fatigue than males. However, there were no statistical significance between males and females.

• PNF and Movement
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• 제7권4호
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• pp.37-43
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• 2009

Purpose : The purpose of this study was to evaluate the effect of core stability training at deep abdominal muscle for balance control of hemiplegic patient. Method : The subject of this study was a 47-year-old man with right hemiplegia. He was treated five times a week for three weeks with core stability training at deep abdominal muscles. Evaluation tool was used Functional reach test(FRT), timed up and go test(TUG) and one leg standing for stroke patients. Result : The FRT distance increase, TUG time decrease, one leg standing time increase core stability training at deep abdominal muscles for right hemiplegia improved was the ability for maintain balance. Posture and control of trunk stability are changing posture, and so which showed significant improve of total balance control. Conclusion : The result of this study showed that core stability training at deep abdominal muscles is an effective treatment for balance control. Therefore, it could be considered as a treatment method in the rehabilitation of stroke patient with poor postural control and imbalance, although further studies are needed.

• Physical Therapy Korea
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• 제27권4호
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• pp.250-256
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• 2020

Background: Unstable surface-based core training can significantly enhance core strength, but no studies have compared the effects of balance pad- and sling-assisted exercises. Objects: To study the effects of unstable surface-based balance pad- and sling-assisted core strength exercises on muscle activity. Methods: Twenty male students aged 20-25 years participated in this study. The effects of three types of core strength exercises, performed with a sling or balance pad, on the activities of three muscles, i.e., the right musculus obliquus externus abdominis (EO), right erector spinae (ES), and right gluteus maximus (GM), were examined. Results: 1) In the glute bridge exercise, the percentage of maximum voluntary contraction of the EO, ES, and GM were significantly different between the balance pad- and sling-assisted exercises. The relative contribution of the ES and GM activities to all muscle activity were not significantly different between the two training types, whereas that for EO showed a significant difference. 2) There was no significant difference in the percentage value of maximum voluntary contraction (%MVC) among the EO, ES, and GM during the "leg-lifting with flat support" exercise, and there were no significant difference in the relative contributions between the two training types. 3) In the "side bridge leg separation exercise", the %MVC of the ES, EO, and GM were significantly different between the two training types. Conclusion: Sling training for core muscles was generally better than balance pad assist training. The majority of physiotherapy patients require core training. Our results could guide physiotherapists in the choice of targeted exercises for these patients.