• Journal of Digital Convergence
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• v.17 no.3
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• pp.463-471
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• 2019

The purpose of this study was to investigate the effect of muscle imbalance on motion of back squat. The isokinetic muscle strength of the 8 subjects was recorded for the knee flexion/extension by the cybex 770 dynamometer. Each subject performed 3 back squats with the long barbell with an intensity of 25% body weight(BW), 50%BW, 100%BW, 125%BW. During the back squat through the recorded kinematic data the subjects' maximum flexion and extension knee angle, center of mass displacement and V-COP were calculated for evaluation of the stability of the movement. For the statistical analysis independent t-test was used. Knee flexion angle and COM displacement are dominated by the reciprocal muscle ratio. V-COP factor was dominated by bilateral extension deficit. Based on the results we can know that as the intensity of the squat increased to a level control was difficult because the muscles' imbalance influenced the movement.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.389-399
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• 2019

The purpose of this study was to investigate the effects of muscle asymmetry of knee joint among elite cyclists on anaerobic pedaling power related capacity. In another word, based on isokinetic strength of Non-Dominant, ND and Dominant, D, side, high, moderate and low ratio of ND to D were classified as High Symmetry Group, Moderate Symmetry Group and Asymmetry Group, respectively. Analysis of muscle asymmetry of extensor's ND and D side might not lead to any difference between the three groups. Based on muscle strength analysis of the flexor's ND and D, there was statistical difference between the groups in ND flexor and in the muscle balance index of the flexor muscle. This result also leads to significant difference in pedaling power functionality, but this effects might not lead to any negative pedaling power. Therefore, among even cyclists who may show almost the same recruitment pattern of ND and D side during pedaling stroke muscle asymmetry could exist but this phenomena might not negatively contribute to the pedaling capacity.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.101-107
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• 2013

In this paper, we were to investigate effect of correction to muscle imbalance in lower limbs according to reduction of weight bearing methods of four point of horizontal shaft using two-belt treadmill. Participants were divided to two group according to each ten peoples who have difference of muscle function in left and right legs over 20%. Experiment progressed forty minutes a day three days a week, total four weeks and we estimated the maximal peak torque and average power for testing joint torque in hip, knee and ankle. The results showed that the correction effect of muscle imbalance to the maximal muscle strength was the most effective in hip joint. Also in knee joint, correction effect of muscular reaction was the most effective too. We thought that reduction of weight bearing methods could be positive effect to correct muscle imbalance in lower limbs.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.2
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• pp.115-124
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• 2017

This study was to develop the balance insole system for detecting and improving the muscle imbalance of left and right side in lower limbs. We were to verify the validation of balance insole system by analyzing the strategy of muscular activities and foot pressure according to sound feedback. We developed the balance insole based FSR sensor modules for estimating the muscle imbalance using detecting foot pressure. The insole system was FPCB have 8-spot FSR sensor with sensitivity range of 64-level. The participants were twenty peoples who have muscle strength differences in left and right legs over 20%. We measured the muscular activity and foot pressure of left and right side of lower limbs in various gait environment for verifying the improvement effect of muscle imbalance according to sound feedback. They performed gait in slope at 0, 5, 10, 15% and velocity at 3, 4, 5km/h. The result showed that the level of muscle imbalance reduced within 30% for sound feedback of balance insole system contrast to high level of muscle imbalance at 169.9~246.8% during normal gait for increasing slope and velocity. This study found the validation of balance insole system with sound feedback stimulus. Also, we thought that it is necessary to research on the sensitivity of foot area, detection of muscle imbalance and processing algorithm of correction threshold spot.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.903-904
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• 2012

• Journal of the Korean Society for Precision Engineering
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• v.30 no.10
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• pp.1095-1101
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• 2013

The purpose of this study was to verify the effect on improvement of muscle strength unbalance according to load deviation protocol during whole body vibration exercise. Seventeen female volunteers (age $22{\pm}3$ years, height $160{\pm}4.9$ cm, weight $49{\pm}.8$ kg) participated in this experiment. The subjects performed squat exercise in WBV platform. Exercise were performed five set a day including 15 time a set, three days a week, and during 4 weeks. Vibration stimulus was 25Hz as frequency and intensity was dominant leg 1mm and non-dominant leg 4mm. The results in WBV group showed that the differences of peak torque in 16% were getting decreasing significantly after 4 weeks from 16.2% to 5.2%. This result means that WBV with load deviation protocol could provide muscle strength exercise for muscle strength balance. Our study found out that WBV of load deviation protocol could provide muscle strength exercise for improving muscle imbalance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.229-238
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• 2013

The aim of this study is to evaluate university canadian paddlers' iso-kinetic muscle function and provide training advices. Eight university paddlers with a 8.5 years career participated in this study. Inbody 720, biodex system III, biodex stabilizer system and THP 2 are used to investigate body component, muscle function(peak torque, average power and work fatigue), agility and dynamic balance. Iso-kinetic muscle function around shoulder, thorax and knee are measured. And then bilateral and unilateral muscle imbalance are calculated at each joint. Results of this study are as follows; University canadian paddlers' BMI average is 24.90 $kg/m^2$ and percent body fat is 12.23%. Reaction time average was 324 msec and balance score at each leg are below 2.0. A3, A4, A5, A6, A8 are needed to train shoulder muscle strength and power. A1, A2, A7, A8 are needed to strengthen shoulder muscle endurance. A2, A5, A8 are needed to train thorax muscle strength and power. A1, A8 are needed to strengthen thorax muscle endurance. Most of paddlers' reciprocal muscle balance ratio on thorax and knee are out of normal range. A2, A3, A4, A8 are needed to train abdominal strength and A3, A5, A6, A7, A8 are needed to train hamstring strength.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1167-1168
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• 2012

• Journal of Digital Convergence
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• v.16 no.6
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• pp.407-416
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• 2018

The purpose of this study is to evaluate elite high school kayaker's iso-kinetic muscle function and provide physical training advices. Biodex system IV, Biodex stabilizer system, Inbody 3.0 and CNP-5403 are used to investigate 11 kayaker's muscle function(peak torque, average power and work fatigue), dynamic balance, body compositions, and flexibility. S4, S5, S8, S10, S11 are needed to train shoulder muscle strength and power. S5, S6, S10, S11 are needed to strengthen shoulder muscle endurance. S5, S7, S8, S10, S11 are needed to train knee muscle strength and power. S1, S4, S5, S10 are needed to strengthen knee muscle endurance. S3, S10, S11 are needed to train wrist muscle endurance. Based on these results we should establish an muscle function enhancing program with periodic inspection for elite kayakers. And standardized training program should be sublated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.37-44
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• 2016

The aim of the present study was to compare the strength, balance, and flexibility across two age groups (older adults vs. young adults). The isokinetic muscle function, ankle ROM, trunk forward flexibility, stability, and antropometric data for the elderly and 46 university students were collected. The results indicated that male older adults possessed relatively low flexibility (2.97cm) among the groups and showed better stability in the right foot than in the left foot and $35^{\circ}$ of plantar flexion ROM, which was not in the normal range. Their peak strength at the knee joint was below 50% of their counterpart. They revealed a hamstring deficit of 18.55%, ankle eversion deficit of 23.08%, and ankle inversion deficit of 19.19%. The results indicated that female older adults possessed comparable flexibility compared to female young adults. The reciprocal muscle strength ratio of both knees was under 50%, and the deficit was 14.32% (extension) and 19.73% (flexion). The ankle plantar flexion peak torque was approximately 62% (left) and 73% (right) of WS's. The ankle dorsi flexion deficit was 25.05% and the plantar flexion was 26.86%. The eversion deficit was 19.97% and the inversion was 21.09%. These results will be significant in establishing an elderly fitness enhancement program and policy.