• 한국운동역학회지
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• 제16권3호
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• pp.75-83
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• 2006

The purpose of this study was to investigate steady-state force depression following active muscle shortening in human tibialis anterior muscle during voluntary contractions. Subjects (n = 7; age $24{\sim}39$ years; 7 males) performed isometric reference contractions and isometric-shortening-isometric contractions, using maximal voluntary effort. Force depression was assessed by comparing the steady-state isometric torque produced following active muscle shortening with the purely isometric reference torque obtained at the corresponding joint angle. In order to test for effects of the shortening conditions on the steady-state force depression, the speed of shortening were changed systematically in a random order but balanced design. Ankle dorsiflexion torque and joint angle were continuously measured using a dynamometer. During voluntary contractions, muscle activation of the tibialis anterior and the medical gastrocnemius was recorded using surface electromyography. Force depression during voluntary contractions, with a constant level of muscle activation, was 12 %, on average over all subjects. Force depression was independent of the speeds of shortening ($13.8{\pm}2.9%$, $10.3{\pm}2.6%$ for 15 and 45 deg/sec over 15 deg of shortening, respectively). The results of this study suggest that steady-state force depression is a basic property of voluntarily-contracting human skeletal muscle and has functional implication to human movements.

• 한국전문물리치료학회지
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• 제15권2호
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• pp.1-10
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• 2008

This study compared the effect of therapeutic exercise with conservative treatment in women with chronic neck pain. Subjects were allocated to control, neck isometric exercise, and cervical stabilization exercise groups consisting of 29, 32, and 31 patients, respectively. The conservative treatment for the control group consisted of hot packs, ultrasound, interferential current therapy, and intermittent cervical traction. The neck isometric exercise group performed a neck isometric exercise and the cervical stabilization exercise group performed a cervical stabilization exercise. To compare the three groups, the levels of perceived pain, neck disability, and psychological depression were assessed on admission, at discharge, and one month after discharge. On admission and at discharge, the pain and neck disability scores did not differ significantly among the groups. However, one month after discharge, both the neck isometric and cervical stabilization exercise groups had significantly improved perceived pain levels as compared to control (p<.05). The improvement in the degree of neck disability was most significant in the cervical stabilization exercise group (p<.05). On comparing the changes in the variables at the three assessments for each group, there was a significant difference between the control and cervical stabilization exercise groups (p<.05). The findings indicate that therapeutic exercises, especially cervical stabilization exercises, are more effective for improving pain and neck disability than conservative treatment.

• 대한물리의학회지
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• 제6권1호
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• pp.93-101
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• 2011

Purpose : The purpose of this study was to investigate the effects of maximum muscle activation of lower extremity of facility dwelled elderly Hansen's disease after isometric trunk exercise for 12weeks. Methods:18 elderly Hansen's disease who isometric trunk exercise for 12weeks were recruited for this study. They were instructed to perform maximum muscle activation of lower extremity after exercise. and the subjects were divided into normal sensory group, sensory loss in left foot group, sensory loss in right foot group and sensory loss in both feet group, according to the sensory condition ability on their soles. Results : After exercise, Hamstring muscle increased significantly (p<.05), and activation of the rectus femoris muscle decreased with a significance (p<05). In terms of Post-hoc test for examining the difference in MVIC according to sensory condition, there was significant difference in the normal sensory group, sensory loss in right and left foot group of left hamstring muscle before the exercise(p=.01) and the normal sensory group, sensory loss in both feet group of right hamstring muscle before the exercise(p=.04). Conclusion : These results indicate that the maximum muscle activation was changed after isometric trunk exercise. it could be improved maximum muscle activation of lower extremity muscle after the exercise although there was sensory loss.

• The Journal of Korean Physical Therapy
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• 제32권4호
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• pp.233-237
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• 2020

Purpose: This study compared the electromyographic activity of the tibialis anterior (TA) and isometric dorsiflexor strength during dorsiflexion according to the toe postures in individuals with ankle dorsiflexor weakness. Methods: Twenty subjects with ankle dorsiflexor weakness participated in this study. The electromyographic activity of the TA and isometric dorsiflexor strength during dorsiflexion between with toe flexion, extension, and neutral postures were measured using an electromyography device and a hand-held dynamometer in individuals with ankle dorsiflexor weakness. One-way repeated measured analysis of variance, and a Bonferroni post hoc test was used. The level of statistical significance was set to α=0.01. Results: The electromyographic activity of the TA was greater with toe flexion during dorsiflexion than with toe extension and neutral postures (p<0.01). The isometric dorsiflexor strength was smaller with toe flexion during dorsiflexion than with toe extension and neutral postures (p<0.01). Conclusions: In individuals with ankle dorsiflexor weakness, the dorsiflexion with toe flexion can help improve the TA electromyographic activity. The toe posture during dorsiflexion for selective TA activation should be considered, especially in individuals with ankle dorsiflexor weakness.

• 대한정형도수물리치료학회지
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• 제14권1호
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• pp.31-38
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• 2008

Purpose : The purpose of this study was to compare the effectiveness of both neuromuscular electrical stimulation(NMES) and isometrical exercise(IE) to strengthen the quadriceps femoris muscle. The relationships between the strength changes and the relative force and duration of training contractions were also studied. Methods : The subjects were divided into three group. The control group(n=6) received no exercise and/or stimulation. The isometric exercise (IE) group(n=6) performed maximum isometric contractions, and the neuromuscular electrical stimulation(NMES)(n=6) engaged electrically stimulated isometric contractions, three days a week for four weeks. Results : Results showed that both IE group and NMES group were found to have an increase in strength significantly greater(p<0.05) than the control group at 4 week. But between IE group and NMES group were not found to have an difference in strength significantly. Conclusion : The relative increase in isometric strength, using IE and NMES, may be determined by the ability of the subjects to tolerate longer and more forceful contractions. Suggestions for further research and implications for the clinical of IE and NMES for strength-training are discussed.

• 한국전문물리치료학회지
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• 제1권1호
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• pp.67-74
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• 1994

Our purpose of this study was to determine the most effective cool-down exercise. The recovery times of dynamic strength after isometric and isotonic cool-down exercise were measured immediately post cool-down exercise, 30 seconds later and 60 seconds later in 30 normal, healthy men from 19 to 29 years, using dumbells(Model, Iron). The recovery time of dynamic strength had a significant positive correlation with isotonic and isometric cool-down exercise using the Chi-square method (p<0.01). Sources of significant differences were determined by the Wilcoxon signed-ranks test (p<0.01). The isometric cool-down exercise significantly shortened the recovery time of dynamic strength. We suggest that the isometric cool-down exercise may be more effective than isotonic cool-down exercise in shortening the recovery time of dynamic strength.

• 국제물리치료학회지
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• 제4권1호
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• pp.505-509
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• 2013

This study has investigated the effect of isometric contractile force and muscle activity applying sperficial heat according to the time from the biceps brachii muscle. In this study, 20 university students participants without musculoskeletal and neurological disorders. By applying a hot pack 5min, 10min, 20min and 30min respectively. After that measurement are skin temperature, contractile force and muscle activity. Skin temperature of the hot 5 min applied that rapidly changing. Increasing the time it takes to apply a variance has been reduced(p<.001). Isometric contractile force was not statistically significant but highest when applying the hot pack 5 minutes and lowest when applying the hot pack 30 minutes(p<.001). Muscle activity and median frequency was highest when applying the hot pack 5 minutes. To analyze the above results, it was found that isometric contractile force and muscle activity changed according to the applying time. These result lead us to the conclusion that this study will be more evidence for changes in muscle contraction to apply hot pack on clinic.

• The Journal of Korean Physical Therapy
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• 제33권5호
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• pp.224-230
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• 2021

Purpose: The purpose of this study was to investigate the effects of the fascia distortion model (FDM), one of the fascia treatments, on unstable ankle subjects. This was done through the chronic ankle instability tool (CAIT) questionnaire on maximum isometric muscle strength, proprioception, dynamic balance, and maximum angle. Methods: An experiment was conducted using the chronic ankle instability tool questionnaire on males and females in their twenties who suffered from ankle instability. Before the experiment, maximum isometric strength, proprioceptive, dynamic balance, and maximum angle were measured. The fascia distortion model was applied and then measurements were taken again to compare and analyze the changes. Analysis was carried out using the paired t-test. Results: After applying the fascia distortion model, maximum isometric strength, proprioceptive, dynamic balance, and maximum angle significantly improved (p<0.05). Conclusion: This study found that the fascia distortion model method was effective in improving maximum isometric strength, proprioceptive, dynamic balance, and maximum angle. The results suggest that the fascia distortion model method is a new intervention that could be used for subjects with chronic ankle instability.

• Korean Journal of Mathematics
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• 제17권1호
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• pp.1-13
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• 2009

For an isometric immersion $f:M{\rightarrow}{\bar{M}}$ of Finsler manifolds M into $\bar{M}$, we compare the intrinsic Chern connection on M and the induced connection on M: We find the conditions for them to coincide and generalize the equations of Gauss, Ricci and Codazzi to Finsler submanifolds. In case the ambient space is a locally Minkowskian Finsler manifold, we simplify the above equations.

• 대한수학회보
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• 제55권3호
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• pp.967-970
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• 2018

The aim of this paper is to show that there exists a weakly quasisymmetric homeomorphism $f:(X,d){\rightarrow}(Y,d^{\prime})$ between two locally compact non-complete metric spaces such that $f:(X,d_h){\rightarrow}(Y,d^{\prime}_h)$ is not quasi-isometric, where dh denotes the Gromov hyperbolic metric with respect to the metric d introduced by Ibragimov in 2011. This result shows that the answer to the related question asked by Ibragimov in 2013 is negative.