Min-Sik Yong

The effect of forward head posture on muscle activity during neck protraction and retraction.

[Purpose] The present study was performed to investigate whether forward head posture (FHP) affects muscle activity. [Subjects and Methods] Twenty subjects attending Y university in Gyeongsangnam-do, Republic of Korea. They were divided into two groups according to craniovertebral angle: a control group (n=10) and a FHP group (n=10). Electromyography electrodes were attached to the upper fibers of the trapezius, middle fibers of the trapezius, the splenii (splenius capitis and splenius cervicis), and the sternocleidomastoid (SCM) muscle to measure muscle activity during the neck protraction and retraction. [Results] EMG activities of the middle trapezius, splenii, and SCM muscle showed significant differences between the control group and the FHP group. However, the EMG activity of the upper trapezius muscle showed no significant difference between the two groups during neck protraction and retraction. [Conclusion] The results suggest that FHP alters the muscle activity in neck protraction and retraction.

Effects of skilled reach training with affected forelimb and treadmill exercise on the expression of neurotrophic factor following ischemia-induced brain injury in rats

[Purpose] The aim of the present study was to investigate effects of skilled reach training with affected forelimb and treadmill exercise on the expression of neurotrophic factor following ischemia-induced brain injury in rats. [Subjects and Methods] Thirty male Sprague-Dawley rats were divided into 3 groups randomly: namely, the control sacrified 2 weeks after surgery, skilled reach training with forepaw contralateral to brain injury for 2 weeks, and treadmill exercise for 2 weeks. Transient focal cerebral ischemia was induced by intraluminal occlusion of the left middle cerebral artery. After that, skilled reach training and treadmill exercise were conducted. Western blot analysis was performed to investigate expressions of neurotrophic factors. [Results] There were significant differences in brain-derived neurotrophic factor and nerve growth factor expression between the control group and the experimental group. There were no significant differences in brain-derived neurotrophic factor and nerve growth factor expression between the skilled reach training group and the treadmill exercise group. [Conclusion] Skilled reach training and treadmill exercise can affect the expression of neurotrophic factors.

Effects of craniocervical flexion exercise on upper-limb postural stability during a goal-directed pointing task

[Purpose] This study investigated the effects of craniocervical flexion exercise on upper-limb postural stability by measuring upper-limb postural tremor during a goal-directed pointing task. [Subjects and Methods] Twenty-four subjects were randomly assigned to the exercise or control group. The exercise group performed craniocervical flexion exercise four days per week for five weeks. Upper-limb postural tremor was measured by using a three-dimensional electromagnetic motion tracking system (trakSTAR™, Ascension Technology Corporation, Burlington, VT, USA) during a goal-directed pointing task. [Results] In the exercise group, the range and velocity of the trajectories of the shoulder, wrist, and finger in the lateral direction improved significantly. However, no significant changes were observed in the control group. [Conclusion] Craniocervical flexion exercise reduces the range and velocity of upper-limb postural tremor, thereby increasing postural stability.

Correlation between head posture and proprioceptive function in the cervical region

[Purpose] The aim of the present study was to investigate correlation between head posture and proprioceptive function in the cervical region. [Subjects and Methods] Seventy-two subjects (35 males and 37 females) participated in this study. For measurement of head posture, the craniovertebral angle was calculated based on the angle between a horizontal line passing through C7 and a line extending from the tragus of the ear to C7. The joint position sense was evaluated using a dual digital inclinometer (Acumar, Lafayette Instrument, Lafayette, IN, USA), which was used to measure the joint position error for cervical flexion and extension. [Results] A significant negative correlation was observed between the craniovertebral angle and position sense error for flexion and extension. [Conclusion] Forward head posture is correlated with greater repositioning error than a more upright posture, and further research is needed to determine whether correction of forward head posture has any impact on repositioning error.

Effect of ankle proprioceptive exercise on static and dynamic balance in normal adults

[Purpose] The present study was conducted to investigate whether ankle proprioceptive exercise affects static and dynamic balance in normal adults. [Subjects and Methods] Twenty-eight normal adults were recruited to measure their static and dynamic balancing before and after the proprioceptive exercise. A subject stood with bare feet on the round supporting platform of the device for measuring balance, and the investigator entered the age and the height of the subjects and set his/her feet on the central point of the monitor screen. Training of ankle proprioceptive sense for the movements of plantar-flexion and dorsiflexion was performed. In the training of joint position sense in plantar-flexion and dorsiflexion, the plantar-flexion and the dorsiflexion were set as 15°, respectively. [Results] The static balancing did not show significant differences in average, while the dynamic balancing showed significant differences. [Conclusion] Ankle proprioceptive exercise can affect dynamic balance.

Analysis of vastus lateralis and vastus medialis oblique muscle activation during squat exercise with and without a variety of tools in normal adults

[Purpose] The present study investigated the effects of squat exercises with and without a variety of tools including a gym ball, wedge, and elastic band on the vastus lateralis and vastus medialis oblique muscles. [Subjects and Methods] A total of twenty healthy subjects with no history of neurological, musculoskeletal injury, or pain in the lower extremities were recruited. All subjects performed four types of exercise (conventional squat exercise, squat exercise with a gym ball, squat exercise with a wedge, squat exercise with an elastic band). [Results] There were no significant differences between exercises in comparison of the vastus lateralis muscle activity. In the squat exercise with a wedge, significantly higher activity of the vastus medialis oblique muscle was found compared with in the squat exercise with an elastic band. [Conclusion] The present study suggests that the conventional squat exercise can be one of the useful interventions for patients with patellofemoral pain syndrome.

Effect of exercise on the expression of nerve growth factor in the spinal cord of rats with induced osteoarthritis.

[Purpose] We examined the impact of exercise on the expression pattern of nerve growth factor in the spinal cord of rats with induced osteoarthritis of the knee joint. [Subjects and Methods] To produce monosodium iodoacetate-induced arthritis, rats were administered 3 mg/50 µL monosodium iodoacetate through the interarticular space of the right knee. The animals were randomly divided into four groups: rats sacrificed 3 weeks after 0.9% saline solution injection (shame group, n = 10), rats sacrificed 3 weeks after monosodium iodoacetate injection (control group, n = 10), rats with 4 weeks rest from 3 weeks after monosodium iodoacetate injection (no exercise group, n = 10), and rats with 4 weeks treadmill training from 3 weeks after monosodium iodoacetate injection (exercise group, n = 10). Serial coronal sections of the lumbar spine were cut and processed for immunohistochemistry. [Results] The expression of nerve growth factor was significantly increased in the EG compared with the SG, CG, and NEG. [Conclusion] Increased nerve growth factor expression in the spinal cord due to exercise-induced stimulation can be effective in treating chronic pain. Such treatment will contribute not only to improving the joint function of patients with chronic pain but also their quality of life.

Effects of breathing exercises on resting metabolic rate and maximal oxygen uptake

[Purpose] The aim of the present study is to examine effects of diaphragm breathing exercise and feedback breathing exercise on maximal oxygen uptake and resting metabolic rate. [Participants and Methods] Thirty-eight healthy participants were randomly assigned to two groups; the diaphragm breathing exercise group and the feedback breathing exercise group. The diaphragm breathing exercise group was asked to perform diaphragm respiration, and the feedback breathing exercise group was asked to breathe with feedback breathing device. Maximal oxygen uptake and resting metabolic rate were measured before and after two breathing exercises. [Results] Significant difference was found in maximal oxygen uptake before and after two breathing exercises. There was also significant difference in resting metabolic rate before and after diaphragm breathing exercise. However, significant difference was not found in resting metabolic rate before and after feedback breathing exercise. There were not significant between-group differences in both maximal oxygen uptake and resting metabolic rate. [Conclusion] Diaphragm breathing exercise and feedback breathing exercise could influence maximal oxygen uptake. Diaphragm breathing exercise could influence resting metabolic rate, but feedback breathing exercise could not.

Effect of diaphragm breathing exercise applied on the basis of overload principle

[Purpose] The purpose of this study was to examine effects of diaphragm breathing exercise applied on the basis overload principle on respiratory function. [Subjects and Methods] The subjects of this study were 35 normal adults. They were randomly assigned to two group; the maneuver-diaphragm exercise group and self-diaphragm exercise group. The respiratory function was evaluated using the CardioTouch 3000S (BIONET, Korea) as a pulmometry device. [Results] The maneuver-diaphragm exercise was more effective on functional vital capacity and forced expiratory volume at one second when compared to the self-diaphragm exercise. [Conclusion] According to the results of this study, although the self-diaphragm exercise did not show effects as much as the maneuver one, but the self-diaphragm exercise had a similar effects as the maneuver-diaphragm exercise. The self-diaphragmatic respiration applied on the basis of overload principle may be used as an effective respiratory exercise as a part of home respiration program.

Effects of diaphragm breathing exercise and feedback breathing exercise on pulmonary function in healthy adults

[Purpose] The present study investigated effects of diaphragm breathing exercise and feedback breathing exercise on respiratory function. [Subjects and Methods] Thirty-one subjects were randomly assigned to two groups; the feedback breathing exercise group and the maneuver-diaphragm exercise group. The feedback breathing exercise group was asked to breathe with feedback breathing device, and the maneuver-diaphragm exercise group was asked to perform diaphragm respiration. Respiratory function was evaluated when a subject sat on a chair comfortably. [Results] There was a significant difference in the functional vital capacity and slow vital capacity before and after all breathing exercises. There was a significant between-group difference in functional vital capacity. However, no between-group difference was found in slow vital capacity. [Conclusion] Diaphragm breathing exercise and feedback breathing exercise can affect respiratory function.