• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.150-157
• /
• 2019

The purpose of this study was investigate the effect of gastrocnemius(GCM) muscle length on the dynamic balance and antero-posterior pressure distribution of foot. Thirty subjects were recruited and each subject was classified with control experimental and control group according to GCM muscle length. The experimental group included subjects with shortness of GCM muscle length, the control group included subjects with normal length of GCM. The dynamic balance and antero-posterior pressure distribution of foot were measured by Biorescue equipment. To evaluate dynamic balance, we collected data of limit of stability in antero-posterior direction. We analyzed the data by using independent t-test. The alpha level was set 0.05. The results showed that the dynamic balance and antero-posterior pressure distribution of foot were significantly different between two groups (p<0.05). This study suggests that the shortness of GCM affects anterior limited of stability in dynamic balance and anterior pressure distribution of foot. Therefore, it is important to maintain optimal GCM muscle length for normal balance ability and prevention of musculoskeletal disease.

• The Journal of Korean Physical Therapy
• /
• v.33 no.6
• /
• pp.278-285
• /
• 2021

Purpose: This study investigated the effects of open kinetic chain (OKC) exercise for the gastrocnemius (GCM) and tibialis anterior (TA) muscles on static and dynamic balance and muscle strength. Methods: We recruited 21 healthy participants, dividing them into 3 groups (GCM, TA, and non-exercise). Each group contains 7 participants. Two exercise groups (GCM and TA) performed OKC exercise with elastic bands twice per week for 4 weeks, while non-exercise group did nothing. We obtained the data for static and dynamic balance and muscle strength before and after the intervention. We used the Kruskal-Wallis test to compare and analyze the pre-post-intervention differences among the groups. Results: For static balance, the stability index of the TA group was the lowest for the dynamic platform (p<0.05). The dynamic balance of the TA group increased for the anterior and posteromedial directions (p<0.05). The peak torque increased in the TA group for dorsiflexion (D/F) movement and in the GCM group for plantar flexion movement compared with the other groups, except for the left direction during D/F (p<0.05). Conclusion: OKC exercises with elastic bands were effective for selectively increasing muscle strength. It is clinically thought that strength training for TA muscles will be effective among the muscles of the ankle.

• The Journal of Korean Physical Therapy
• /
• v.26 no.2
• /
• pp.74-81
• /
• 2014

Purpose: The purpose of this study is to compare kinematics and kinetics on the knee joint between stair gait with unstable shoes and barefoot in healthy adult women. Methods: Seventeen healthy adult women were recruited for this study. The subjects performed stair ascent and descent with unstable shoes and barefoot. The experiment was repeated three times for each stair gait with unstable shoes and barefoot. Measurement and analysis of the movements of the knee joint were performed using a three-dimensional analysis system. Results: Statistically significant differences in the knee muscle force of semimembranosus, biceps femoris-long head, biceps femoris-short head and sartorius, patellar ligament, medial gastrocnemius, and lateral gastrocnemius were observed between unstable shoes and barefoot gait during stair ascent. Statistically significant differences in the knee muscle force of sartorius, rectus femoris, medial gastrocnemius, and lateral gastrocnemius were observed between unstable shoes and barefoot gait during stair descent. Statistically significant differences in the knee flexor moment of semitendinosus, biceps femoris-long head, biceps femoris-short head, sartorius, rectus femoris, vastus intermedialis, medial gastrocnemius, and lateral gastrocnemius were observed between unstable shoes and barefoot gait during stair ascent. Conclusion: Therefore, wearing unstable shoes during stair gait in daily life is considered to influence knee joint kinematics and kinetics due to the unstable shoes, and thus suggest the possibility that reducing the risks of pain, and knee osteoarthritis, stabilizing the knee joint caused by changes in the loading of the knee joint.

• The Korean Journal of Physiology
• /
• v.22 no.2
• /
• pp.231-243
• /
• 1988

This study was performed to investigate the mechanism of changes in arterial blood pressure, as a typical example of somatosympathetic reflex, induced by activation of muscular afferent nerves. Cats were anesthetized with ${\alpha}-chloraloae$ (60 mg/kg, i.p.). Afferent fibers in muscle nerve were activated by various method muscle contraction, electrical stimulation of muscle nerves, intraarterial injection of some algesic substances and noxious mechanical stimulation etc-and the evoked changes in arterial blood pressure were monitored. The effects of intravenous or direct spinal administration of morphine on the changes in arterial blood pressure induced by activation of the muscle afferent fibers were observed and also the effects of spinal lesions made in the $L1{\sim}L3$ spinal cord on them were studied to identify the ascending spinal pathways of the somatosympathetic reflexes. Followings are the results obtained. 1) The stimulation of medial gastrocnemius nerve under non-paralyzed condition with C-strength, low frequency (lower than 20 Hz) stimuli elicited a depressor response and a pressor response was elicited with C-strength, high frequency stimuli, of which the maximal response was observed at 100 Hz stimulation. 2) When the animal was paralyzed, depressor response to stimulation of the medial gastrocnemius nerve was observed with C-strength, $0.5{\sim}5Hz$ stimuli although the amplitude of the depressor response was decreased. The maximal pressor response was observed during stimulation with C-strength, $20{\sim}100Hz$ stimuli. 3) Intraarterial injection of some algesic substances induced marked pressor responses while noxious mechanical stimulation of the medial gastrocnemius muscle was not enough to elicit any significant changes (larger than 10 mmHg) in arterial blood pressure. 4) Systemically administered morphine (2 mg/kg) lowered the arterial blood pressure immediately and persistently and it was reversed by administration of naloxone. Direct spinally administered morphine did not elicit any changes. 5) The pressor response elicited by the activation of muscle afferent nerves was strengthened by systemic morphine administration while the depressor response tended to decrease. 6) Morphine administered on the spinal cord directly, decreased pressor response but did not change depressor response. From the above results it is concluded that there are separate groups of afferent nerves in the medial gastrocnemius nerve, which elicit pressor and depressor responses and the spinal ascending pathways of them are also separated from each other.

• Proceedings of the KOSOMBE Conference
• /
• v.1992 no.05
• /
• pp.203-208
• /
• 1992

In order to restore the gait function by functional electrical stimulation(FES) in hemiplegic patients, an electrical stimulator and foot sensor were developed on the basis of optimal parameters which resulted from animal experiments. Physical properties of the soleus muscle were quite different from those of themedial gastrocnemius muscle, that is, the former had a characteristic or slow muscle and the letter had a characteristic of fast muscle in rats. Optimal parameters for electrical stimulation were 0.2ms of pulse width and 20Hz of frequency in the soleus muscle and 0.3ms, 40Hz in the medial gastrocnemius muscle. Amplitude modulated electrical stimulator with -15V of maximal output was made and automatic on-off time if the stimulator was 5 seconds. The foot sensor composed of 3 sensors in 3 pressure points of the foot was made in order to control the gai t function by closed loop feedback system. The gait function was improved by using the stimulator and foot sensor in peroneal palsy. These results suggest that the electrical stimulator with closed loop feedback system may restore the gait function in hemiplegic patients.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.2
• /
• pp.9-19
• /
• 2006

The purpose of this study was to analyze the kinematic variables of the lower limbs joints and the muscle activity for lower limbs during the level and downhill running. The subjects were 6 males of twenties and required to run on the level and downhill which was -7% grade treadmill at 8.3km/h. The running performances were filmed by high speed video camera and EMG signal was gained by ME3000P8 Measurement Unit. Rectus femoris(RF), Vastus lateralis(VL), Gluteus medius(GLU), Biceps femoris(BF), gastrocnemius medial head(GM), gastrocnemius lateral head(GL), Soleus(SO), Tibialis anterior(TA) were selected. The result of this study were as follows: 1. Ankle, knee, hip joint in downhill running showed less movement than the level running but, no significant difference. 2. VL and BF during the support phase in downhill running showed Iess muscle activity than the level running. but RF showed the opposite result. 3. GM, GL, SO adn TA during the supports phase in downhill running showed less muscle activity than the level running.

• The Journal of Korean Physical Therapy
• /
• v.27 no.3
• /
• pp.159-163
• /
• 2015

Purpose: This study aimed to determine the interaction among the neck, trunk, and lower extremities on the non-paretic side in head rotation along with non-paretic-side weight shifting of stroke patients. To compare stroke patients' ability to control posture through muscle activity variation related to pertubation during head rotation along with the non-paretic limb. Methods: We tested 15 hemiplegic patients and 15 normal individuals. Each group's muscle activity was measured by electromyography in neutral head position and head rotation position. We compared each group's resu lt based on measured values in patients' non-paretic neck muscles, trunk muscles, and lower limbs muscles activation. Results: The study showed that muscle activity increased in the sternocleidomastoid muscle (102.26%, 53.00%), splenius capitis muscle (97.93%, 54.93%), erector spinae muscle (241.00%, 127.60%), external oblique abdominal muscle (256.66%, 152.00%), and internal oblique abdominal muscle (252.80%, 152.6%), peroneus longus muscle (117.53%, 137.13%) and gastrocnemius muscle (119.06%, 137.20%), while the results for the sternocleidomastoid muscle, splenius capitis muscle, erector spinae muscle, external oblique abdominal muscle, internal oblique abdominal muscle, peroneus longus muscle, and gastrocnemius muscle showed a statistically significant difference (p<0.05). Conclusion: It is hard for stroke patients to engage in normal movement control under suggested conditions because of the insufficient movement against gravity on the stroke patient's non-paretic side and impaired cooperative patterns. To solve these problems, patients need their bodies to improve through effective movement, resulting in advanced control of their effective and functional activity.

• Journal of Korean Academy of Nursing
• /
• v.39 no.3
• /
• pp.321-328
• /
• 2009

Purpose: The purpose of this study was to determine the effect of Dehydroepiandrosterone(DHEA) administration alone or exercise combined with DHEA before steroid treatment on rat hindlimb muscles. Methods: Male Sprague-Dawley rats were assigned to one of three groups: a steroid group(S, n=10) that had no treatment for 7 days before steroid treatment; a DHEA-steroid group(DS, n=8) that had 0.34 mmol/kg/day DHEA injection once a day for 7 days before steroid treatment and an exercise+DHEA-steroid group(EDS, n=9) that ran on the treadmill combined with 0.34 mmol/kg/day DHEA injection for 7 days before steroid treatment. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected. Body weight, food intake, muscle weight, myofibillar protein content and cross-sectional area of the dissected muscles were determined. Results: The DS group showed significant increases(p<.05) as compared to the steroid group in body weight, and muscle weight of gastrocnemius muscles. The EDS group showed significant increases(p<.05) as compared to the S group in body weight, muscle weight, myofibrillar protein content, and Type II fiber cross-sectional area of soleus, plantaris and gastrocnemius muscles. Conclusion: Exercise combined with DHEA administration before steroid treatment prevents steroid induced muscle atrophy, with exercise combined with DHEA administration being more effective than DHEA administration alone in preventing muscle atrophy.

• Korean Journal of Applied Biomechanics
• /
• v.17 no.2
• /
• pp.239-245
• /
• 2007

The purpose of this study was to compare the electromyography signal's power spectrum mean and median tendencies appearing in the lower extremity during walking while wearing roller shoes. 9 male subjects volunteered who have no experience riding inline-skate or roller-skate, and have no record of musculoskeletal disorder. Subjects walked on treadmill twice for an hour (Once a week, one trial with the roller on and the other without roller, Walking velocity = 1.39 m/s). Electromyography was measured every 15 minute (0, 15, 30, 45, 60 minutes). Surface electrode sticked muscle at rectus femoris(R.F.), vastus lateralis(V.L.), vastus medialis(V.M.), biceps femoris(B.F.), tibialis anterior(T.A.), gastrocnemius lateralis(G.L.), gastrocnemius medialis(G.M.). At Rectus femoris, Vastus Lateralis, Vastus medialis, and Biceps femoris showed no statistically significant decrease of median frequency or mean edge frequency as time passes. Also, between two treatments (wearing the roller shoes vs not wearing the roller shoes), no statistically significant difference. After 60 minutes, mean edge frequency showed statistically significant decrease at tibalis anterior and after 45 minutes, mean edge frequency showed statistically significant decrease compared to wearing roller shoes without the wheels at gastrocnemius lateralis. At gastrocnemius medialis after 30 minutes, median frequency showed statistically significant decrease, and showed statistically significant difference compared to the control group. Wearing the roller shoes with wheels for a long time resulted in statistically significant decrease of mean edge frequency and median frequency in lower extremity, especially in shank muscles. Increase of wearing time of roller shoes and walking on a bumpy road wearing roller shoes with wheels result fatigue and thus, danger of injury.

• The Korea Journal of Herbology
• /
• v.23 no.2
• /
• pp.159-168
• /
• 2008

Objectives : The present study has been undertaken to investigate the effects of Dipsaci Radix on Muscle Fiber Atrophy and MyoD Expression in Gastrocnemius of MCAO Rats Methods : In order to investigate effects of Dipsaci radix on the skeletal muscle atrophy following stroke, cerebral infarct was induced by the middle cerebral artery occlusion (MCAO) in the rats. Water extract of Dipsaci radix (184.4 mg/100 g) was treated for 4 weeks, once a day orally, after the MCAO. Effects were evaluated with muscle fiber type composition and cross-sectioned area of muscle fibers in gastrocnemius of the unaffected & affected hind limbs. And MyoD protein expression in gastrocnemius was demonstrated with immunohistochemistry and western blotting. Results : Obtained results were as follows; 1. Infarct volume was not attenuated by Dipsaci radix treatment in the MCAO rats. 2. At the affected-side hind limb of the MCAO rats, the increase of type-I fibers and the decrease of type-II fibers were induced by Dipsaci radix treatment. 3. At the affected-side hind limb of the MCAO rats, decreases of cross-sectioned areas of type-I and type-II fibers were attenuated by Dipsaci radix treatment. 4. At the affected-side hind limb of the MCAO rats, MyoD positive cells were increased by Dipsaci radix treatment. 5. At the affected-side hind limb of the MCAO rats, MyoD expressions were increased by Dipsaci radix treatment. Conclusions : These results suggest that Dipsaci radix has a protective effect against muscle atrophy, through the inhibition of the muscle cell apoptosis, following the central nervous system demage.