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This study investigated the feasibility of the Infrared (IR) sensor-based walking aids for detecting the gait intention. To compensate for the defects of Force Sensing Resistors (FSRs) or force sensors, such as the velocity control problem on gait slopes, we used IR sensors to investigate knee joint anterior displacement in order to recognize the gait intention. We also measure leg muscle activities and foot pressure, in order to verify our investigation. We placed two IR sensors on the rollator center to sense left and right leg walking intentions. We took EMG signals of four leg muscles, and analyzed them. Foot pressure analysis parameters were the measured force and mean pressure. We conducted experiments on twenty young healthy adults. The results show that knee joint anterior displacement increases according to gait slope and velocity. We confirm similar results of knee joint anterior displacement through the IR sensors.

This study shows the improvement of muscle activity and muscle strength imbalance in the lower extremities through independent exercise loads in vibration platform. Twenty females of age 20 participated in this study. The subjects were divided into WBV group, with more than 10% of muscle strength imbalance between left and right the lower extremities, and control group, with less than 10% of muscle strength imbalance between left and right the lower extremities. As the prior experiment showed, different exercise postures provide different muscular activities. As a result, the highest muscular activity was found to be in the low squat posture. Therefore, the LS posture was selected for the exercise in this experiment. Vibration intensities were applied to dominant muscle and non-dominant muscle, and the vibration frequency was fixed at 25Hz for the WBV group. The control group was asked to perform the same exercise as the WBV group, without stimulated vibration. This exercise was conducted for a total of 4 weeks. As a result, the WBV group which showed an average deviation of 16% before the experiment, tended to decrease approximately to 5%. In this study, vibration exercise using load deviation is shown to be effective in improving the muscle strength imbalance.

The purpose of this study was to evaluate muscle function and basal physical fitness in relation to muscle balance pattern using rowing machines. Twenty four subjects participated in this study, using three different rowing machines. Rowing exercises were performed for twenty-five times a set, four sets a day, 3 days a week, for 8 weeks. Biodex system 3(Biodex Medical Systems Co., New York, USA) was used to measure joint torques in the elbow, shoulder, lumbar and knee of subjects, for analyzing muscle function. The evaluation of basal physical fitness included body composition, muscle strength, muscle endurance, muscle reaction, agility, flexibility and explosive power. Before the experiment, significant differences of joint torques in the elbow, shoulder, lumbar and knee were present between subjects in the group. After the rowing exercise, significant improvement in every joint was witnessed. All aspects of basic fitness increased significantly, and the most improvement was observed in muscle strength from the joint torque results. As shown in the following results, every joint it was evident to have improved by more than 30% with the use of dependent load deviation type over the previously used water load method. This means that it is more effective for enhancing muscle strength and endurance to keep the muscle balance using dependent load deviation. The human body maintains motor coordination of muscle contraction during exercise. The muscle balances in the upper-lower and left-right arms could assist with effective activation of motor coordination. In this paper, an exercise method using dependent load deviation was demonstrated to be more efficient for improving muscle imbalance and strengthening muscles.

In this paper, we investigated several parameters with effect on the compressive force to assess the mechanical properties of interventional device. We find several parameters are highly influential and others are not. In our evaluation system, we prepared a box-shaped PVA-H and silicone with realistic geometry and carried out the measurement and evaluation of the pushability by using load cell machine. The parameters of velocity, position of device in the system do not affect the compressive force, whereas the length of catheter from the tip to fixed point is one of the most influential parameters for the force. Several behaviors such as passing through the curve or slip and stop can be observed and defined using this system. The balance of the bending force and the pushing force may make the tip with behavior of slip and stop or passing thorough the curve. The investigation of the evaluation system confirmed that high reproducibility with short error bar is indicated. The observation with movie record is also an advantage of our system because the high transparency of materials with silicone and PVA-H can check the inside of artery.

The objectives were to assess the trunk and leg muscle activities during the trunk tilt exercise by a 3D dynamic exercise device capable of active and passive movements, to study the evaluation of Root Mean Squire (RMS), and to investigation the influence of the trunk positions on these muscle activities. Eighteen healthy volunteers were selected. None of the subjects had any history of lumber and trunk muscle problems. Rotation capability was enabled for the investigation of A (anterior), R (right), P (posterior), L (left), AR (anterior right), AL (anterior left), PR (posterior right), PL (posterior left) tilt directions. EMG signals of trunk (rectus abdominis, external obliques, latissimus dorsi, erector spinae) muscles and leg (rectus femoris, Biceps femoris, Tibialis Anterior, gastrocnemius) muscles were taken out. Root Mean Squire (RMS) values were calculated. The results of this study indicate that different exercise patterns can be applied depending on the exercise types, which are appropriate and necessary to each user. We believe that the human body can be maintained in equilibrium through the interaction between the position and movement execution of the human body, contributing to the improvement of body balance control. Further quantitative data collection and analysis related to the development of various spinal stabilization exercise programs is required. In the near future, we will conduct a study concerning the effects of trunk tilt exercise in active and passive modes on the strength of the tilting muscles and postural balancing ability.

The effect of stent design parameters such as porosity, pore density, number of strands, and strut angle to the artery were studied in vitro using particle image velocimetry (PIV). Five mesh stents were implanted into a sidewall aneurysm model. The flow features in a sidewall aneurysm silicone phantom model were investigated at a Reynolds number of 300. It was found that the lowest porosity stent had the best value for velocity and vorticity reduction in an aneurysm pocket. The stent with higher pore density had a tendency to decrease the mean and maximum velocities, but it was not superior to the effects of porosity. In addition, investigation of the evaluation system confirmed that higher stent strut angles to the parent artery had a tendency to lower mean velocity, as shown by PIV and CFD. However, this effect was relatively smaller compared to porosity and pore density. Our evaluation system suggested the best combinations of parameters for the development of an ideal stent would be lower porosity, higher pore density, and higher strut angle. The results obtained in this study indicated that our evaluation system could be useful for various purposes related to evaluation of endovascular interventional devices.

This research was performed to assess the effects of angled whole body vibration on muscle activity of the lower limbs, by examining adults in their twenties during squat exercises, taking into account two variables of exercise intensity (vibration frequency and gradient). Twenty healthy males in their twenties with previous experience of more than 6 month's weight training and no past medical history were included in this study. The experiment was performed by participating in squat exercises which consisted of 3 sets (1 set = 5 seconds x 3 repetitions of exercise), and the muscle activities of the Rectus Femoris, Vastus Lateralis, Vastus Medialis were measured with variation in the gradients of 0°, 10°, and 20°, and vibration frequencies of 20, 30, and 40 Hz. At 30 and 40 Hz, the vastus lateralis showed the highest change in muscle activity, while activity of the vastus medialis also increased significantly. Analysis of muscle activity according to the gradient showed a significant increase of the vastus lateralis at 20°, while the highest muscle activity at 20° was observed for the vastus medialis. In comparison of the change in lower limb muscle activity according to simultaneous stimulation, at a gradient of 10°, high activity was shown in muscle, while at 20°, high muscle activities were produced at 40 Hz in the vastus lateralis, 40 Hz in the rectus femoris, and both 30 and 40 Hz in the vastus medialis.

The aim of this study is to verify the effect of indoor horse riding exercise on basal physical exercise and lumbar muscular function. The subjects included were 20 healthy females, who participated in the horse riding exercise using SRider (Rider Co. & ChonbuK National Univ, Korea) for 30 minutes per day, 3 days per week, over a period of 8 weeks. The subjects were divided into 4 groups as follows, with 10 subjects in each group: Postural Balance Exercise mode (PBE), Abdomen Exercise mode (ADE), Whole body Exercise mode (WBE), and Multiple Exercise (MTE). Isokinetic muscular function test was performed before and after the horse riding exercise, to assess the effect of horse riding on basal physical exercise and lumbar muscular function. The test result on basal physical exercise and isokinetic muscular function showed improvements with variable degree in the back muscle strength, maximum joint torque, total work, and muscular acceleration time. The result signifies that the horse riding is an antagonistic exercise mainly performed on waist and abdomen area, and the machine induces persistent muscle contraction and causes myotonic induction enhancing the muscle strength. Indoor horse riding exercise proved its effectiveness for senior or the disabled people who need muscle exercises but have difficulties performing outdoor activities.

In this study, we assessed indoor horse riding exercise's effects on basal physical exercise and activities of daily living (ADL) function using horse riding equipment, involving elderly test subjects (in their sixties). The participants were 20 people with no impediment to activity. They participated in experiments that lasted 60 min per day, 3 days per week, over 8 weeks, using the "SRider" (Rider Co. and Chonbuk National University Korea).We measured trunk flexion, sit-up, whole-body reaction, leg strength, and maximal oxygen uptake as basal physical fitness parameters. Also, 3-m gait, single stance with eyes open, and single stance with eyes closed, as ADL functions, were estimated once per month. The leg strength and whole body reaction result were significantly higher than before the exercise program. Moreover, the results of the 3-m walking ability alone increased significantly among the ADL functions. These findings indicate that the horse riding exercise may activate continuous muscular contraction, maintaining the tonus of the muscles. The continuous movement of horse riding could be lead to isometric muscle contraction in the lower limbs. These results suggest that the horse riding exercise develops muscle power and muscle reactions with exercise.

This study was performed to assess the improvement of muscle strength imbalance in the lower limbs using a four point weight bearing reduction system with a two-belt treadmill. Participants, each having differences in muscle function of the left and right legs of over 20%, were divided into two groups of ten. The participants were involved in experiments progressing 40 minutes per day, 3 days per week, during a period of 4 weeks. The maximal peak torque and average power were measured for testing joint torque in the hip, knee and ankle. The results showed the improvement of muscle imbalance as assessed by the maximal muscle strength was the most effective in the hip joint, while the improvement of muscular reaction was the most effective in the knee joint. We suggest that the method of weight bearing reduction could be sufficient to reduce muscle imbalance in the lower limbs.

This study investigated the characteristics of dynamic postural responses when subjects attempted to maintain an upright standing position on a support plate during continuous sinusoidal perturbation in the anterior-posterior direction. Fif- teen healthy young subjects participated in the experiment. Body movement patterns during the perturbation were captured and analyzed using a 3D motion analysis system (APAS 3D motion analysis, Ariel Dynamics Inc.). Seven markers were at- tached on the subject's body to measure and analyze the motion patterns. The markers were positioned at the head, chest, hip, right knee, left knee, right ankle, and left ankle. Five different frequencies of motion were applied to the support surface: 0.1, 0.5, 1.0, 1.5, and 2.0 Hz with a 4-cm path of motion at the base. The experiments measured dynamic postural responses in a condition were subjects had their eyes open. The results showed that the median frequency of the knee and ankle increased in all frequency bands. Following an increase in the frequency of the perturbation, the postural control strategy was changed from the ankle strategy to a combined strategy. These experimental results could be applied to the dynamic postural training for the elderly and to rehabilitation training for patients to improve their ability for postural control.

A new training system that can adjust training intensity and indicate the center pressure of a subject was proposed by applying controlled electric current to the Magneto-Rheological damper. The experimental studying on the muscular activities were performed in lower extremities during maintaining and moving exercises, which were processed on an unstable platform with Magneto rheological dampers and recorded in a monitor. The electromyography (EMG) signals of the eight muscles in lower extremities were recorded and analyzed in certain time and frequency domain. Muscles researched in this paper were rectus femoris (RF), biceps femoris (BF), tensor fasciae latae (TFL), vastuslateralis (VL), vastusmedialis (VM), gastrocnemius (Ga), tibialis anterior (TA), and soleus (So). Differences of muscular activities during four moving exercises were studied in our experimental results. The rate of the increment of the muscular activities was affected by the condition of the unstable platform with MR dampers, which suggested the difference of moving exercises could selectively train each muscle with varying intensities. Furthermore, these findings also proposed that this training system can improve the ability of postural balance.