• Journal of the Korean Society for Precision Engineering
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• v.24 no.8 s.197
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• pp.130-137
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• 2007

The optimized prosthetic mass distribution was a controversial problem in the previous studies because they are not supported by empirical evidence. The purpose of the present study was to evaluate the effect of prosthetic mass properties by modeling musculoskeletal system, based on the gait analysis data from two above-knee amputees. The joint torque at hip joint was calculated using inverse dynamic analysis as the mass was changed in knee and foot prosthetic components with the same joint kinematics. The results showed that the peak flexion and abduction torque at the hip joint were 5 Nm and 15 Nm when the mass of the knee component was increased, greater than the peak flexion and abduction torque of the control group at the hip joint, respectively. On the other hand, when the mass of the foot component was increased, the peak flexion and abduction torque at the hip joint were 20 Nm and 15 Nm, greater than the peak flexion and abduction torque of the control, respectively. The hip flexion torque was 4.71-fold greater and 7.92-fold greater than the hip abduction torque for the knee mass increase and the foot mass increase on the average, respectively. Therefore, we could conclude that the effect of foot mass increase was more sensitive than that of knee mass increase for the hip flexion torque. On the contrary, the mass properties of the knee and foot components were not sensitive for the hip abduction torque. In addition, optimized prosthetic mass and appropriate mass distributions were needed to promote efficiency of rehabilitation therapy with consideration of musculoskeletal systems of amputees.

• The Journal of Korean Physical Therapy
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• v.10 no.1
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• pp.81-98
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• 1998

Isokinetic evaluation of trunk flexors and trunk extensors was performed at $60^{\circ}/sec\;and\;120^{\circ}/sec$ of angular velocity by using cybex 6000TEF Unit on 31 healthy male white workers and 15 post-operative HILD patients with no significant difference in mean age and mean body weight between two groups, and compared each other. The purpose of this study is to obtain the isokinetic normative strength values and endurance latins for Dunk extensors and trunk flexors, and is to provide a guideline for rehabilitation program of post-operative HILD patients. The collected data were analyzed by ANOVA, Duncan's Nyktuoke Range Test, and Pearson correlation coefficiency in PC-SAS program, The results obtained were as follow ; 1. Post-operative subjects has lower isokinetic values than normal subjects in peak torque, peak torque $\%$ by body weight, total work, total work $\%$ by body weight, average power, average power $\%$ by body weight, TAAE of trunk flexors and trunk extensors, and there are significant differences with statistic value in trunk extensors at $60^{\circ}/sec$ and in trunk flexors and trunk extensors at $120^{\circ}/sec$ between two groups(p<0.05). 2. Pest-ooperative subjects has lower values for angle of peak torque than normal subjects in trunk extensors, and there are significant differences with statistic value at $60^{\circ}/sec$ and $120^{\circ}/sec$ between two groups. 3. Post-operative subjects has higher values for endurance ratios than normal subjects in trunk extensors and flexors, but there are no significant differences with statistic value between two groups. 4. Post-operative subjects has higher values than normal subjects in peak torque ratios, total work ratios, average power ratios of trunk flexors to trunk extensors, and there are significant differences with statistic value between two groups(p<0.01). 5. There is significant positive-correlation with statistic valve between peak torque and height and body weight in normal subjects(p<0.05), but Thjere is significant negative-correlation between peak torque of trunk extensor at $120^{\circ}/sec$ and age (p<0.05). 6. There is significant positive-correlation with statistic value between peak torque of trunk flexors and body weight in post-operative subjects (p<0.05), but There is significant negative-correlation between peak torque of trunk extensor add age (p<0.05). In conclusion, post-operative subjects have greater weakness in trunk musculature than normal subjects, especially there is more significant weakness in trunk extensors than in trunk flexors

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.8 no.2
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• pp.31-43
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• 2002

The subjects of this study were 15 woman soccer players and 15 untrained woman students at H-Cheju University. Each subject was measured on the muscle strength and peak torque of knee extensors and knee flexors with isokinetic load ($60^{\circ}$/sec, $180^{\circ}$/sec). The results were as follows: 1. There was no significant difference between right and left leg strength measured isokinetically in each group. 2. The peak torque of knee extensors and flexors was significantly higher in scoccer players than untrainded students (p<0.001). 3. For the angle of knee joint showing the highest peak torque, there was significant difference between soccer players and untrained students in knee extensors(p<0.05) and right flexors (p<0.01). 4. For knee H/Q ratio, there was significant difference between two groups(p<0.05). 5. For the total work and average power at $180^{\circ}$/sec, there was significant difference between two groups in knee extensors(p<0.001) and flexors(p<0.01). 6. In soccer players at $60^{\circ}$/sec, there were significant correlations between peak torque and height and between peak torque and weight.(p<0.001). 7. For the muscular contraction velocity at $60^{\circ}$/sec, there was significant difference between two groups in flexors (p<0.01). 8. For the muscular indurance at $180^{\circ}$/sec in extensors and flexors, there was no significant difference between two groups(p<0.05). In conclusion, there were significantly higher in peak torque, contraction velocity, knee joint's angle with the highest peak torque, H/Q ratio, total work and average power in woman scoccer player than general students. But there was no significant difference in muscular endurance. Soccer performance is based on the various components including muscular endurance that is one of the most important components. So it is necessary that the training method to improve the various components (especially including muscular endurance) should be done.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.139-148
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• 2009

D. W. HAN. Y. R. AHN., N. J. LEE and E. J. LEE. Effects of Combined Restistance Training Program of Concentric and Eccentric Contraction Using Theraband on Shoulder Rotation Torque Max and Peak Power. Korean Joumal of Sport Biomechanics, Vol. 19, No. 1, pp. 139-148, 2009. The purpose of this study was to find out that combined concentric with eccentric resistance training program using Thera-Band was more effective than only concentric resistance training program on shoulder rotation torque max and peak power. 30 female students were randomly assigned to 3 equal group; concentric and eccentric, concentric, non training group. Subjects were tested in concentric and eccentric torque max and peak power of internal and external rotation using a CON-TERX isokinetic dynamometer. Subjects in training group participated in their regular five times a week for 4 weeks. After exercise, in concentric and eccentric training group, concentric and eccentric torque max, and peak power of internal rotator at 60 deg/sec were increased significantly. concentric peak power at 120 deg/sec were increased significantly. In concentric training group, only concentric peak power of internal rotator at 60 and 120 deg/sec was increased. In conclusion, we found out that combined concentric with eccentric resistance training program using Thera-Band was more effective than only concentric resistance training program on shoulder rotation torque max and peak power.

• Physical Therapy Rehabilitation Science
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• v.9 no.2
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• pp.113-119
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• 2020

Objective: The vibration device is one of the most commonly used warm-up devices not only for healthy athletes but also for healthy individuals. Therefore, this study aimed to investigate the immediate effects of local vibration on ankle plantar flexor muscle activation and peak torque in healthy adults. Design: One-group pretest-posttest design. Methods: This was a single-group study comprising a total of 36 (16 males and 20 females) participants. The average age of the 36 participants was 22.3 years. All the participants' concentric and eccentric peak torques of the gastrocnemius lateralis muscle were measured using an isokinetic device. Simultaneously, the participants' muscle activity was measured by surface electromyography. After the pre-experimental data were collected, the participants comfortably sat on the prepared chair with their hips and knees flexed to 90°. While in sitting position, local vibration was applied for 10 minutes using a 1:1 ratio intermittent pulsing mode device based on a previous study. Then, the post-experimental data were collected immediately after the local vibration by performing a similar process performed during the pre-experimental data collection. Results: The results showed a significant difference in muscle activity and eccentric peak torque (p<0.05). On the contrary, concentric peak torque values showed an insignificant difference with pre- and post-value. Conclusions: The results of this study demonstrated that local vibration can be possibly considered as one of the effective ways to increase ankle plantar flexor muscle activity and muscle performance, specifically the eccentric peak torque, in healthy adults.

• Journal of Life Science
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• v.12 no.6
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• pp.780-785
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• 2002

The purpose of this study is to investigate isokinetic strength changes of knee joint in accordance with short-term weight loss of wrestlers. For this purpose, 14 male wrestlers of a K technical high school in B city participated in our research. The wrestlers were divided into two groups; one group of the wrestlers didn't lose any weight, and the other lost over 5% of their weights. The isokinetic strength was also observed before and after weight loss. The isokinetic strenght test were processed at test speed of the$60^{\circ}C$/sec, $90^{\circ}C$/sec, and $250^{\circ}C$/sec with the CYBEX NORM system(Cybex 770＋TMS, USA). Peak torque, peak torque %BW, total work, total work %BW, and endurance ratio were measured. Results showed that the isokinetic strength after the short-term weight loss of wrestlers decreased meaningfully Although endurance ratio didn't show any meaningful difference in our research, but more accurate research may find out the relationship between short-term weight loss and the endurance ratio of isokinetic strength.

• The Journal of Korean Physical Therapy
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• v.10 no.1
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• pp.45-52
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• 1998

Since isokinetic concise can give an evaluation of muscle strength with great accuracy and objectively, it is widely used as the one of the important methods for evaluation of muscle performance. The purpose of this investigation was to compare values uncorrected for gravity with values corrected for gravity and to determine the effect of making this correction on knee flexors and extensors at three speeds. This investigation measured values isokinetically at $60^{\circ}/sec,\;120^{\circ}/sec,\;and\;180^{\circ}/sec$ in 14 male and 17 fermale university students. The gravity effect torque(GET) is the torque resulting from the effect of gravity on the combined weight of the leg and dynamometer arm. The GET was added to the measured extensors peak torque and subtraced from the flexors peak torque to yield gravity corrected values. Failure to consider GET greatly underetimated extensors torque and overtestimated flexors torque. Physical therapists must remember the importance of making the gravity correction in patients with reduced torque output where the gravitational torque is a greater percentage of the measured torque to ascertain correctly the relative strength of antagonists inversely affected by gravity.

• Journal of Korean Physical Therapy Science
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• v.3 no.2
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• pp.951-961
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• 1996

Isokinetic exercise is dynamic, but the spped of movement must be regulated so that the resistance is in ratio to the force applied at each point throughout the full range of motion. The purpose of this study is to comparise with trunk flexors & extensors of isokinetic evaluation of pre-exercise and post-exercise in operated laminectomy & disectomy patients. 7 subjects were examined at $120^{\circ}$/sec and $60^{\circ}$/sec each 15 days. The results were as follows; 1. Peak torque of extensors on $60^{\circ}$/sec showed significant difference statistically(p<0.05), but peak torque of flexors on $60^{\circ}$/sec showed no significant difference statistically. 2. Trunk flexors/extensors ratio of peak torque of $60^{\circ}$/sec showed no significant difference ststistically. 3. Peak torque % B.W of extensors on $60^{\circ}$/sec showed significant difference statistically(p<0.05), but peak torque % B.W of flexors on $60^{\circ}$/sec showed no significant difference statistically. 4. TAE of extensors on $60^{\circ}$/sec showed significant difference statistically (p<0.05), but TAE of flexors on $60^{\circ}$/sec showed no significant difference. 5. Total work of flexors & extensors on $60^{\circ}$/sec showed significant difference statistically (p<0.05). 6. Average power of flexors & extensors on $120^{\circ}$/sec showed significant difference statistically(p<0.05). 7. Endurance ratio of flexors & extensors on $120^{\circ}$/sec showed no significant difference statistically. 8. Set total work of flexors & extensors on $120^{\circ}$/sec showed significant difference statistically(p<0.05). 9. TAE of extensors on $120^{\circ}$/sec showed significant difference statistically(p<0.05), TAE of flexors on $120^{\circ}$/sec showed no significant difference statistically. 10. Total work of flexors & extensors on $120^{\circ}$/sec showed significant difference statistically (p<0.05).

• Physical Therapy Korea
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• v.20 no.3
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• pp.45-53
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• 2013

The purpose of this study was to examine the differentiation of proprioception, invertor and evertor muscle strength, and time to peak torque at a velocity of $300^{\circ}/sec$ of the ankle joint in people with or without functional ankle instability (FAI). Nineteen subjects with a history of ankle sprain participated. All subjects were divided into FAI group ($n_1=9$, Cumberland ankle instability tool (CAIT)${\leq}24$) and a control group ($n_2=10$) based on their CAIT scores. Isokinetic dynamometer was used to measure the sense of active joint position of the ankle at mid-range and end-range of an inversion motion and invertor as well as the evertor muscle strength and time to peak torque at $300^{\circ}/s$. The FAI group showed a statistically reduction in invertor and evertor muscle strength and time to peak torque when compared to the control group (p<.05). Muscle strength and time to peak torque of the invertor and evertor, as well as the sense of active joint position at end-range were also lower in the FAI group than in the control (p<.05). Correlations between CAIT score and position sense at end-range (r=-.577) and invertor muscle strength (r=.554) were statistically significant (p<.05). Individuals with FAI showed reduction in invertor and evertor muscle strength and recruitment time as well as in proprioception of the ankle joint. Thus, proprioception and invertor and evertor muscle strength of the ankle joint at fast angular velocity may be investigated when examining and planning care for individuals with FAI.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.2
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• pp.240-257
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• 2016

This study determines the effect of 3D compression pants and Kinesio taping on muscular function of the leg during knee joint flexion and extension. Eight males participated in the experiment, wearing basic pants (BP), Kinesio taping on bare skin (KT), 3D compression pants with (KTP) and without Kinesio taping (CP). The test protocol for isokinetic muscular function was composed of four sets at three angular velocities (60, 180, $240^{\circ}/sec$) using Cybex 660. Peak torque and work per repetition of the lower limbs of eight males were analyzed from the result of Cybex. Agility and power of the subjects were examined from side step and sergeant jump. Peak torque, average power, work per repetition, force decay time of subjects wearing CP and KTP were significantly better than BP or KT, especially at low angular velocity of $60^{\circ}/sec$. The time to generate peak torque of subjects wearing BP was the longest, while the force-decay time of BP was the shortest. The application of Kinesio tape on skin did not increase muscle peak torque, work and power, but did shorten the time to generate peak torque.