• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.1009-1018
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• 2019

This paper describes the design and implementation of a rehabilitation medical device based on a EMG measurement. Rehabilitation systems are controlled using BLDC motors and motor drives. The BLDC motor drive controls the operation and the speed controls the drive through the external servo motor. In addition, potentiometer coupled to the outside of the motor transmits information about the position of the load being rotated by the motor. The rehabilitation algorithm is controlled by limiting the maximum angle of 0 to 120 by utilizing the motor according to the user setting stage during the rehabilitation exercise. The walking algorithm compensates motor control for the low leg of the signal using the difference value of the signal obtained with the surface denser attached to both inner muscles. The motor and surface denser are utilized for the walk motion to control the maximum angle of 0 to 80.

• Clinical Pain
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• v.20 no.2
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• pp.105-121
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• 2021

Objective: Physiologically, the vastus medialis muscle is the first muscle to undergo muscle atrophy, and it was thought that pain in patients with knee osteoarthritis could be reduced if this muscle could be strengthened and stabilized. The purpose of this study was to prove the effectiveness in knee osteoarthritis using polydioxanone sutures that have been tried in other musculoskeletal areas. Method: Forty knee osteoarthritis patients voluntarily participated in the study, and divided into 30 polydioxanone suture needle (MEST-B2375 produced by Ovmedi Co.) and 10 sham needle (without suture). And the needles were inserted into the vastus medialis muscle. In all patients, safety evaluation including blood tests and ultrasonography as well as efficacy evaluation including isometric maximal contractile strength of quadriceps muscle, weight bearing pain, impression of change, quadriceps angle, rescue drug intake were evaluated up to 30 weeks after the procedure. Results: Isometric maximal contractile strength showed a significant improvement at 4 weeks after the procedure in the polydioxanone suture group, and the weight-bearing pain showed a significant improvement at every visit in the polydioxanone suture group compared with baseline values. Patient global impression of change score showed significant improvement at 20 and 30 weeks, and clinical score showed improvement at every visit. Conclusion: Insertion of polydioxanone sutures showed improvement in muscle strength and knee pain by supporting and fixation of the vastus medialis muscle in patients with degenerative knee osteoarthritis. Insertion of polydioxanone sutures is considered to have a therapeutic effect in knee osteoarthritis patients.

• PNF and Movement
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• v.18 no.1
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• pp.65-75
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• 2020

Purpose: The purpose of this study was to investigate the differences in muscle thickness and ground reaction force of the vastus medialis oblique and vastus lateral oblique muscles during squats at ankle angles of toe 0°, toe in 10°, and toe out 10°. Methods: In this study, 9 male and 17 female students in their 20s participated in a randomized controlled trial and were compared according to the ankle angles of toe 0°, toe in 10°, and toe out 10°. To determine the reliability and measurement of muscle thickness according to ankle angle using ultrasound equipment and muscle thickness, the participants' ankle angles-toe 0°, toe in 10°, and toe out 10°-were measured three times at the vastus medialis oblique and vastus lateralis oblique muscles during squats. At the same time, the maximum vertical ground reaction force was measured with a force plate. A total of three measurements were taken and averaged, and two minutes of squat movements were assessed between ankle angles to prevent target action. Results: The results of this study illustrated that the reliability of the vastus medialis oblique muscles and vastus lateralis oblique muscles in ankle angle was high. The difference in muscle thickness was significantly greater in comparing the toe out 10° angle with the toe 0° angle than between toe in 10° and toe out 10° in vastus medialis oblique and vastus lateralis oblique (p < 0.05). There was no statistically significant difference between the ankle angle of toe 0° and toe in 10° (p > 0.05). The maximum vertical ground reaction force was significantly greater at toe out 10° than at the ankle angle of toe 0° and toe out 10° and between toe in 10° and toe out 10° (p < 0.05). There was no statistically significant difference in the comparison between toe 0° and toe in 10° (p > 0.05). Conclusion: Squatting at an ankle angle of toe out 10° increases the dorsi flexion; thus, the stability of the ankle and the thickness of both oblique muscles increased to perform more effective squats. In addition, as the base of support widens, it is thought that the stability of the posture increases so that squat training can be performed safely.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.326-333
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• 2016

This case study identified the effects of joint mobilization on knee pain, isokinetic strength, muscle tone, and muscle stiffness in an elite volleyball player with a knee injury. The subject had experienced cartilage defects of the left knee joint and underwent surgery to correct the condition. The patient complained of continuous pain in the left knee joint in daily life in addition to pain during exercise. The study was conducted from August 5 to 12, 2015 and joint mobilization was applied to the left knee joint for 15 minutes once a day for 8 days. Knee pain was measured using a visual analogue scale, and the concentric peak torque of the quadriceps and hamstring muscles was measured using an isokinetic muscular strength measurement device. The muscle tone and stiffness of the rectus femoris muscle, vastus medialis, and vastus lateralis on the injured side were measured using a myotonometer. All the measurements were conducted before and after the intervention. Joint mobilization was effective in reducing knee pain on the injured side, increasing the concentric peak torque of the quadriceps and hamstring muscles on both sides, and increasing the muscle stiffness of the quadriceps muscle on the injured side. Concentric peak torque of the quadriceps muscle on the injured side increased a great deal as the number of joint mobilizations was increased, largely diminishing the difference in concentric peak torque between the normal side and injured side. On the other hand, joint mobilization was ineffective in improving the hamstring to quadriceps strength ratio on the injured side. While this study suggests that joint mobilization can be an effective intervention to improve the knee pain, isokinetic strength, and muscle stiffness of elite volleyball players, it should be performed alongside training for an appropriate strength ratio.

• 한국체육학회지인문사회과학편
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• v.56 no.4
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• pp.575-584
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• 2017

The purpose of this study was to examine the effects of low intensity resistance training speed on body composition, muscle activity and muscle strength in obese middle-aged women. The subjects (n = 12) were randomly assigned to normal resistance training speed group (NSG, n = 6) and slow resistance training speed group (SSG, n = 6). NSG was performed the for 3 sets ${\times}$ 35 times and total 3-s per repetition (eccentric: 1-s, isometric: 1-s, concentric: 1-s), and SSG performed for 3 sets ${\times}$ 15 times and total 7-s per repetition (eccentric: 3-s, isometric: 1-s, concentric: 3-s). Both groups performed the low intensity resistance training at 30% of 1-RM for 105-s per set, rest for 1 min between sets, rest for 3 min between exercises, and 2~3 times per week, for 4 weeks. The body composition, muscle activity and muscle strength were measured before and 4 week after resistance training. WHR at NSG and body fat at SSG were significantly decreased after resistance training compared with before (P<.05). Ｍuscle activity of biceps brachii, vastus medialis and vastus lateralis at both groups were significantly decreased after resistance training compared with before (P<.05, P<.01). Muscle strength of biceps curl and leg extension at both groups were significantly increased after resistance training compared with before (P<.01). However, body composition, muscle activity and muscle strength did not show statistically significant differences between the groups. Our results suggest that body composition, muscle activity and muscle strength should closely related to the performance time of resistance training (development time of muscle contraction), rather than resistance training speed (repetition frequency).