Background: Technological developments have led to the creation of a mechanical device capable of providing a representative massage as a passive treatment. The use of mechanical massage offers the distinct advantage of being user-friendly and available for use at any given time. Objectives: To investigated present the outcomes of utilizing a massage bed on the range of motion (ROM) and pressure pain threshold (PPT) in patients diagnosed with chronic low back pain. Design: ABA design of a single case study. Methods: To measure the ROM of the subject's trunk flexion, extension, lateral flexion, and rotation, a tape measure and goniometer were utilized. Furthermore, PPT was measured using an electronic pressure pain meter. Baseline A and Baseline A’ periods were conducted for 5 consecutive days without intervention. Following the baseline periods, a massage bed intervention was administered for 1 hour daily for a total of 10 days during the Intervention B period. Daily assessments were performed, and the Intervention B period was conducted after the intervention. Results: The ROM effect was confirmed in trunk lateral flexion and rotation, while the PPT was effective in both L1, right L2, left L4, and left L5. Conclusion: The results of this study confirmed that the use of a massage bed improved the ROM and PPT in patients suffering from chronic back pain. Further randomized controlled trials involving a larger sample size are necessary to validate these findings.

Background: Patients with low back pain (LBP) experience misalignments in the center of pressure (COP) and muscle imbalances due to frequent onesided posture adjustments to avoid pain. Objectives: To identify the effects of Squat Exercises with Vertical Whole-Body Vibration on the Center of Pressure and Trunk Muscle Activity. Design: Randomized controlled trial. Methods: Thirty LBP patients with an imbalance in the COP were sampled and randomly assigned to an experimental group of 15 patients who under went an intervention involving squat exercises with vertical WBV and a control group of 15 patients who were treated via a walking intervention. As pretests before the interventions, the subjects’ COP was identified by measuring their stability index (ST), and erector spinae, rectus abdominis, transverse abdominis, gluteus medius muscle activity was analyzed by determining the % reference voluntary contraction (%RVC) value using surface electromyography while sit to stand. After four weeks, a post test was conducted to remeasure the same variables using the same methods. Results: Statistically significant differences were found in the ST (P<.01) and trunk muscle (P<.05, P<.001) in the experimental group before and after the intervention. In terms of the differences between the left- and right-side (RL) muscle activity, only the transverse abdominis (TrA) and gluteus medius (GM) exhibited statistically significant increase (P<.05). A comparison of the groups showed statistically significant differences in the TrA with respect to muscle activity (P<.05) and in the RLTrA and RLGM in terms ofthe difference between left- and right-side muscle activity (P<.01). Conclusion: Squat exercises with vertical WBV produced effective changes in the COP of patients with LBP by reducing muscle imbalances through the delivery of a uniform force. In particular, strengthening the TrA and reducing an imbalance in the GM were determined to be important factors in improving the COP.

It is well-known that the primary role of a vehicle exhaust system is to reduce the exhaust emissions and noise caused by a running vehicle. However, as vehicle exhaust systems are being evaluated and improved in various ways to satisfy consumer needs, technologies for reducing noise and vibration are significantly being developed. The biggest challenge in designing an exhaust system is generating the optimal back pressure and flow velocity for a running vehicle, thereby maximizing the performance, while simultaneously reducing the noise caused by the exhaust emissions. In this study, we designed the junction chamber shapes of various exhaust systems, which are applicable to V6 and above engines, and conducted a CFD analysis of the exhaust gas flowing through an exhaust pipe. In addition, we precisely measured the noise and vibration caused by a vehicle and analyzed the correlation.

Background: Lumbar stabilization (LS) improve the thickness of the quadratus lumborum (QL) muscle and muscle activity of the gluteus medius (GM) muscle during hip abduction in a side-lying position in patients with low back pain (LBP). Objects: The purpose of this study was to assess the effects of LS on muscle thickness of QL and muscle activity of GM during hip abduction in side-lying in patients with LBP. Methods: The study included 32 patients with LBP, who were randomly divided into the control group and experimental group, each with 16 patients. All subjects performed 35° preferred hip abduction (control group) and 35° hip abduction with LS (experimental group) during side-lying. An ultrasonography and a surface electromyography were used to measure the thickness of the QL muscle, and the muscle activities of the GM muscle respectively. Independent t-test was used to compare the muscle thickness of the QL and the muscle activity of the GM muscle, respectively. Results: Anterio-posterior diameter in the muscle thickness of QL muscle was decreased significantly in hip abduction with LS more than in preferred hip abduction (p<.001), but medio-lateral diameter in the muscle thickness of QL muscle was not significantly different between in preferred hip abduction and in hip abduction with LS (p=.06). The muscle activity of GM was increased significantly in hip abduction with LS more than in preferred hip abduction (p<.001). Conclusion: These findings suggest that hip abduction with LS could be recommended as a hip abduction for LS and a prevention unwanted compensatory pelvic lateral tilting movement.

Asymmetric sitting posture may cause asymmetric buttock pressure and unilateral low back pain (LBP). The purpose of this study was to compare the differences of buttock pressure between both sides, and pelvic angle (sagittal and coronal planes) during typing in a sitting position on a pressure mat (Baltube) in individuals with and without unilateral LBP. Ten subjects with unilateral LBP and ten subjects without unilateral LBP were recruited for this study. Buttock pressure was measured using a pressure mat and pelvic angles were measured using a palpation meter. The subjects performed typing in a sitting posture for 30 minutes. Pressure data were collected and averaged at initial term (from start to first minutes) and final term (last minutes of 30 minutes). Angles of pelvic tilting were measured after 30 minutes typing. Pressure asymmetry values (difference in pressure between both sides) were calculated at the initial and final terms. A two-way analysis of variance was used to compare the differences between the initial and final pressure asymmetry values in subjects with and without unilateral LBP. An independent t-test was applied to compare the pelvic tilt angles between the two groups. To compare the change of pressure from the initial term to the final term between the symptomatic and asymptomatic sides in the unilateral LBP group, a paired t-test was applied. In the unilateral LBP group, the pressure asymmetric value at the final term was significantly greater than that of the initial term (p<.05). The angle of pelvic tilting in coronal plane was significantly greater in the unilateral back pain group compared to the without unilateral LBP group (p<.05), however, there was no significant difference in the angle of pelvic tilting in the sagittal plane between the two groups (p>.05). In the unilateral LBP group, the change of pressure from the initial term to the final term was significantly less in the symptomatic side (-6.90 ㎜Hg) than the asymptomatic side (5.10 ㎜Hg). This asymmetric sitting posture may contribute to unilateral LBP in the sitting position. Further studies are needed to determine if asymmetric weight bearing in sitting causes unilateral LBP or if unilateral back pain causes asymmetric weight bearing, and if the correction of asymmetric weight bearing in sitting can reduce unilateral LBP.

Pressure ulcers are serious complications of tissue damage that can develop in patients with diminished pain sensation and diminished mobility. Pressure ulcers can result in irreversible tissue damage caused by ischemia resulting from external loading. There are many intrinsic and extrinsic contributors to the problem, including interface tissue pressure, shear, temperature, moisture, hygiene, nutrition, tissue tolerance, sensory and motor dysfunction, disease and infection, posture, and body support systems. The purposes of this study were to investigate the relationship between buttock interface pressure and seating position, wheelchair propulsion speed. Seated-interface pressure was measured using the Force Sensing Array pressure mapping system. Twenty subjects propelled wheelchair handrim on a motor-driven treadmill at different velocities (40, 60, 80 m/min) and seating position used recline (, , ) with a wheelchair simulator. Interface pressure consists of average (mean of the pressure sensor values) and maximum pressure (highest individual sensor value). The results of this study were as follows; No significant correlation in maximum/average pressure was found between a static position and a 40 m/min wheelchair propulsion (p>.05). However, a significant increase in maximum/average pressure were identified between conditions of a static position and 60 m/min, and 80 m/min wheelchair propulsion (p<.05). No significant correlation in maximum pressure were found between a recline (neutral position) and a , , or recline of the wheelchair back (p>.05). No significant difference in average pressure was found between conditions of a recline and both a and recline of wheelchair back. However, a significant reduction in average pressure was identified between conditions of a and recline of wheelchair back (p<.05). This study has shown some interesting results that reclining the seat by reduced average interface pressure, including the reduction or prevention in edema. And interface pressure was greater during dynamic wheelchair propulsion compared with static seating. Therefore, the optimal seating position and seating system ought to provide postural control and pressure relief. We need an education on optimal seating position and a suitable propulsion speeds for wheelchair users.

Powder forging with a back pressure was investigated for production of automobile and compressor parts made of a rapidly solidified Al-Si alloy powder. Disk-shaped green compacts made of a rapidly solidified Al-Si alloy powder were hot forged, and hubs were formed by loading back pressure on their top. The influences of the back pressure and die temperatures on forgeabiliy and properties of parts made of a rapidly solidified Al-Si alloy powder were examined. This method was also applied to the production of a scroll part. The results of these studies are summarized as follows : 1. A back pressure on the hub top is very effective for consolidation and preventing crack formation in the hub. 2. When a back pressure tess than 98 MPa is applied, the forging pressure increases by the same amount of the applied back pressure. With more than 98 MPa, the forging pressure increases further due to an increased friction at the hub side. 3. Die temperatures higher than approximately 670k are needed in order to consolidate well the hub top without cracks.

To calculate back the soil pressure acting on culverts, a technique for estimating the actual soil pressure has been established. The comparison between the design soil pressure and the real soil pressure is included.