Dongwook Han

The effects of elbow joint angle changes on elbow flexor and extensor muscle strength and activation.

[Purpose] This research investigated the relationship between elbow joint angle and elbow flexor and extensor strength and activation, taking into consideration the length-tension tension curve of the muscle. [Subjects] There were 30 research subjects in total, 15 male and 15 female college students from Busan S University who had no functional disabilities that might affect measurement of muscle strength and muscle activation, and none had they experienced any damage in their upper extremities or hands. [Methods] The elbow joint angles were positioned at angles of 56°, 70° and 84°, and then muscle strength and activation were compared. Repeated measures ANOVA was used for statistical analysis, and the paired t-test was used to identify the difference between each angle. We used the SPSS for windows (ver. 21.0) statistical software and a significance level of α=0.05. [Results] The results showed that muscle strength and activation of the biceps was highest when the joint was placed at 56°. On the other hand, for the triceps, the result was highest when the joint angle was placed at 84°. [Conclusion] The tests confirmed that muscle strength and activation were highest at the joint angle at which the muscle was stretched to 20% more than the resting position in concentric contraction.

Muscle activation of paraspinal muscles in different types of high heels during standing

[Purpose] This study researched the effects of different types of high heels on the muscles surrounding the cervical spine, the thoracic spine, and the lumbar spine by analyzing muscle activation of the paraspinal muscles during standing while wearing high heels. The high heels were all of the same height: 8 cm. [Subjects and Methods] The 28 subjects in this experiment were females in their 20s with a foot size of 225–230 mm and a normal gait pattern. To measure the muscle activation of the paraspinal muscles, EMG electrodes were attached on the paraspinal muscles around C6, T7, and L5. The muscle activation during standing while wearing 8-cm-high wedge heels, setback heels, and French heels was then measured. The measurements were performed 3 times each, and the mean value was used for analysis. [Results] The levels of muscle activation of the paraspinal muscles induced by standing on wedge heels, setback heels, and French heels in the cervical and lumbar areas were significantly higher than those induced by standing on bare feet. But there was no significant difference according to the heel types. [Conclusion] The height of the heels presented a greater variable than the width of the heels on the muscle activation of paraspinal muscles. Therefore, wearing high heels is not recommended for those who have pain or functional problems in the cervical and/or lumbar spine.

The effects of core muscle release technique on lumbar spine deformation and low back pain.

[Purpose] The purpose of this study was to examine the effects of the core muscle release technique on correction of lumbar deformation and alleviation of low back pain. [Subjects] Ninety patients diagnosed with lumbar deformation and low back pain participated in this study. [Methods] The participants were divided into three groups according to method of treatment. The first group was treated with the core muscle release technique (CRT), the second group was treated with general exercise, and the third group was treated with electrotherapy. The core muscle release technique group received 50-minute of the core muscle release technique 5 times a week for 2 weeks, and the participants in this group were instructed not to receive any other treatments. After the 2 weeks of treatment, the patients were reexamined. The general exercise group performed Williams flexion exercises and McKenzie extension exercises 5 times a week for 2 weeks. The electrotherapy group was treated by application of electrotherapy with an interferential current therapy machine (TM-301. TOPMED. Seongnam, Republic of Korea) to the abdominal muscles and back muscles of the lumbar region. [Results] The data suggest that the core muscle release technique, general exercise, and electrotherapy all helped to decrease the alignment angle and VAS score. Of these treatment methods, however, the core muscle release technique was the most effective for treatment of lumbar spine deformation and low back pain. [Conclusion] The core muscle release technique was most effective for correction of lumbar spine deformation and pain alleviation.

The Effects of Abdominal Hollowing in Lower-limb PNF Pattern Training on the Activation of Contralateral Muscles.

[Purpose] The purpose of this study was to determine the effects of abdominal hollowing during lower-limb proprioceptive neuromuscular facilitation (PNF) training on the activation of contralateral muscles. [Subjects] Twenty male college students without symptoms or signs of muscular or nervous disease participated in this experiment after signing a consent form. [Methods] All the subjects were measured with electromyography (EMG) in a muscle activation test before and after abdominal hollowing. In the PNF program, the lower-limb pattern of PNF training, was maintained for 5 seconds, followed by a 2-minute break. This was repeated three times. The resting time between sets was 30 minutes. Surface EMG (Keypoint, Medtronic Inc., USA) was used for the measurements, and the highest value of three measurements was used in the analysis. [Result] The results revealed a significant change in the muscular activation of the opposite-side lower limbs. The muscular activations of the vastus lateralis, tibialis anterior, semitendinosus and gastrocnemius were increased significantly after the abdominal hollowing. [Conclusion] The findings suggest that abdominal hollowing in PNF pattern training can be effective at promoting muscular activation of the contralateral muscles. To promote muscular activation of the opposite side in lower-limb PNF pattern training, abdominal hollowing should be considered to improve the effect of PNF pattern training.

The Effects of the Height and the Quality of the Material of Popular Heel-up Insole on the Mean Plantar Foot Pressure during Walking

This study determined the effects of the height and the quality of the material of popular heel-up insole on mean plantar foot pressure during walking. Seven healthy college students who are studying at S university in Busan were as participants in this study. After sufficiently explaining about the research to the subjects before the experiment, mean plantar foot pressures were examined using F-Scan Pressure Measure System 5.23 for the gait with shoes inserted insole and the data were compared among the height and the quality of material of insoles. In the result, there was a difference significantly in the mean plantar foot pressure followed the height of insoles both left and right. Especially, mean plantar foot pressure in left indicated significantly lower in 3 cm and 5 cm insoles than in 0 cm and 1 cm insoles. Also mean plantar foot pressure in right showed significantly lower in 3 cm and 5 cm insoles than in 0 cm, and indicated significantly lower in 5 cm insoles than in 1 cm and 3 cm insoles. The mean plantar foot pressure followed the quality of the material of insoles were different significantly. In left, the mean plantar foot pressure of urethane poly-acetyl insole was lower significantly than urethane poly-acetyl inserted air insole, power-gel insole and jelly insole. And the mean plantar foot pressure of urethane poly-acetyl insole was lower significantly than power-gel insole and jelly insole in right. We showed that 3 cm and 5 cm insoles in the height of insoles and Urethane poly-acetyl insole in the quality of material were suitable to reduce a fatigue which is felt in plantar foot during the walking.

Effects of cervical self-stretching on slow vital capacity

[Purpose] This study investigated the effects of self-stretching of cervical muscles, because the accessory inspiratory muscle is considered to improve pulmonary function. [Subjects] The subjects were 30 healthy university students 19–21 years old who did not have any lung disease, respiratory dysfunction, cervical injury, or any problems upon cervical stretching. [Methods] Spirometry was used as a pulmonary function test to measure the slow vital capacity before and after stretching. The slow vital capacity of the experimental group was measured before and after cervical self-stretching. Meanwhile, the slow vital capacity of the control group, which did not perform stretching, was also measured before and after the intervention. [Results] The expiratory vital capacity, inspiratory reserve volume, and expiratory reserve volume of the experimental group increased significantly after the cervical self-stretching. [Conclusion] Self-stretching of the cervical muscle (i.e., the inspiratory accessory muscle) improves slow vital capacity.

The Effects of Active Scapular Protraction on the Muscle Activation and Function of the Upper Extremity

[Purpose] The purpose of this study was to determine the effects of adjusting the scapula into its ideal position through active scapular protraction on the muscle activation and function of the upper extremity. [Subjects] Twenty female college students aged 19–21 without any physical or functional disability were the subjects of this study. They had no history of injury to their upper extremities or hands. [Methods] After the initial measurements the experimental group was asked to perform active scapular protraction; then, their grip strength and muscle activation were measured again. Every action was maintained for 5 seconds and repeated 3 times. The mean values of the measurements were analyzed. A resting of 1 minute was given between each action. [Results] The results revealed a significant change in the experimental group’s grip strength after active scapular protraction had been performed. The surrounding muscles of the scapula, such as the serratus anterior, upper trapezius, flexor carpi ulnaris, flexor carpi radialis and palmaris longus, showed significant changes in muscle activation after active scapular protraction. The muscles of the upper extremity also showed significant changes after active scapular protraction. [Conclusion] The adjustment of scapula into its ideal position through active scapular protraction increased the activations of the muscles surrounding the shoulder joint and improved the function of the upper extremity.

Analysis of the influential factors of maximal-effort expiratory capacity of elderly women

[Purpose] The purpose of this study was to find the influential factors of maximal-effort expiratory capacity of elderly women. [Subjects and Methods] The subjects of this study were 83 healthy elderly women. The study’s methods and purpose were explained and these women agreed to participate. The maximal-effort expiratory capacity was measured using spirometry (Pony FX, COSMED Inc., Italy). We measured forced vital capacity, forced expiratory volume in 1 second, forced expiratory volume in 1 second/forced vital capacity, maximal expiratory flow 75%, maximal expiratory flow 50%, and maximal expiratory flow 25%. [Results] Regarding forced vital capacity and forced expiratory volume in 1 second, it was found that height and age were influential factors. Regarding forced expiratory volume in 1 second/forced vital capacity %, maximal expiratory flow 75%, maximal expiratory flow 50%, and maximal expiratory flow 25%, it was found that only age was an influential factor. [Conclusion] This study demonstrated that the most influential factors of maximal-effort expiratory capacity of elderly women were age, and the second influential factor was height. We noticed that weight was the least influential factor among them.

The effect of chiropractic techniques on the Cobb angle in idiopathic scoliosis arising in adolescence

[Purpose] The purpose of this study was to examine whether chiropractic techniques would reduce the curvature of idiopathic scoliosis, which commonly occurs in elementary school children. [Subjects] The subjects of this study were 5 healthy elementary students who listened to an explanation of the study methods and purpose of the study and agreed to participate in the experiment. [Methods] The Cobb angle was measured by taking an X-ray (FCT-1, Dongmun, Goyangsi, Republic of Korea) taken from the rear, using X-ray film. The method of intervention this study used was application of chiropractic techniques. Spinal correction was carried out for 30 minutes per session, which included soft tissue massage, 3 times a week for 8 weeks. [Results] It was established that the Cobb angle was noticeably decreased after 4 weeks of the intervention. Post Hoc analysis revealed that the Cobb angle noticeably decreased after 4 weeks compared with the Cobb angle before the chiropractic techniques were applied. However, no significant difference in Cobb angle was evident after the fourth week. [Conclusion] This study demonstrated that chiropractic techniques can effectively reduce the Cobb angle within as little as 4 weeks. So, we can confirm that the chiropractic techniques were effective for reducing the curvature of idiopathic scoliosis.

Analysis of Plantar Foot Pressure according to Insole Types during Treadmill Gait

Objective : The purpose of this study was to analyze the foot-pressure distribution of 2D(2 dimensional form) & 3D(3 dimensional form; a customized arch-fit for posture correction) insoles for assessing their biomechanical functionality. Background: Recently there has been increased interest in both foot health and foot pain patients. Analysis of the plantar pressure was often used to solve the problems of the foot displayed by such people as rheumatoid arthritis patients. Method : Subjects who participated in this study were 17 female university students who had no previous injury experience in lower limbs and a normal gait pattern. The shoe size of all subjects was 240 mm. Two models of insoles of 2D(typical flat insole 2 dimensional form) and 3D(special production 3 dimensional form) were selected for the test. Using the Pedar-X system and Pedar-X insoles, 4.0 km/h of walking speed, and a compilation of 50 steps walking stages were used to analyze foot-pressure distribution. Results : Results of the foot-pressure distribution and biomechanical functionality on each insole were as follows; analyses of mean plantar pressure, maximum plantar pressure, maximum vertical GRF, and plantar pressure curve shape all showed overall low plantar pressure and GRF. Conclusion : This can be evaluated as an excellent insole for low levels on the plantar pressure and GRF. Therefore, it is possible to conclude that according to this analysis the 3D Customized Arch-fit Insole was better than 2D insole on the basis of these criteria.