The effect of suboccipital muscle inhibition and posture correction exercises on chronic tension-type headaches.

BACKGROUND: Compared with healthy people, patients with chronic tension-type headache (CTTH) are likely to have forward head postures (FHP) and a higher number of active trigger points (aTrP) on the suboccipital muscle. OBJECTIVE: This study aims to verify how the suboccipital muscle inhibition (SMI) on aTrPs and the FHP correction exercise can effectively reduce symptoms of the CTTH patients. METHOD: The subjects of this study were 45 individuals with CTTH, divided into three groups of 15 patients each: a) the SMI group using the myofascial release technique; b) the SMIEx group subject to both the SMI therapy and FHP correction exercises; and c) the control group. Group A and B were given the relevant interventions twice a week for four consecutive weeks, and went through the headache impact test (HIT-6) and examinations on the pressure pain threshold (PPT) of the headache areas, the type and number of myofascial trigger points (TrP), the soft tissue PPT, and the posture before and after the intervention. RESULTS: There was a significant improvement in the HIT-6, the headache PPT, the soft tissue PPT, the TrP, and the posture in Group A and B patients to whom the SMI technique and SMIEx interventions were applied. The biggest reduction and increase in the HIT-6 and the headache PPT respectively were seen in the SMIEx group. CONCLUSION: According to this study, the SMIEx can be an effective intervention for patients with CTTH.

Photochemical Reduction of Silver Precursor and Elastomer Composite for Flexible and Conductive Patterning.

The development of ink-based printing techniques has enabled the fabrication of electric circuits on flexible substrates. Previous studies have shown that the process method which uses a silver (Ag) precursor (AgCF3COO) and electrospun poly(styrene-block-butadiene-block-styrene) (SBS) can yield patterns with high conductivity and stretchability. However, the only method to reduce the Ag precursor absorbed in SBS is chemical reduction using a toxic solution. Here, we developed a process to fabricate a high-conductivity pattern via laser reduction by photo-chemical reaction without toxic solutions. The Ag precursor was absorbed in electrospun SBS to form a composite layer (composite SBS) with modified properties, that could more effectively absorb the photon energy than SBS without the Ag precursor. We analyzed the properties of this material, such as its light absorption coefficient, heat conductivity, and the density of both SBS and composite SBS to allow comparison of the two materials by numerical simulation. In addition, we fabricated patterns on highly heat-sensitive substrates such as burning paper and a polyethylene terephthalate (PET) thin film, as the pattern can be implemented using very low laser energy. We expect the proposed approach to become a key technology for implementing user-designed circuits for wearable sensors and devices on various flexible substrates.

Immediate effects of isometric trunk stabilization exercises with suspension device on flexion extension ratio and strength in chronic low back pain patientss.

BACKGROUND: Recent clinical research has supported the use of suspension devices in rehabilitation procedures both in practice and in theory. Although a longitudinal study has reported on the use of suspension devices among asymptomatic subjects, it is necessary to investigate the immediate effects of suspension exercises in patients with CLBP. OBJECTIVE: The present study aims to investigate changes in neuromuscular activation after the prescription of suspension exercises in patients with CLBP. A secondary aim was to determine whether practical flexion and extension strength can be effectively enhanced. METHODS: Before and after suspension exercise, flexion extension (FE) ratio and trunk strength of flexion and extension were measured. Patients performed two types of suspension exercises: supine bridge and forward leaning exercises. The paired t-test was used to compare the FE ratio and strength data. Pearson correlation coefficient was performed to study the correlation between measured variables. RESULTS: Compared to the pre-exercise measurements, the flexion-extension ratio and trunk extension strength was significantly increased at the post-exercise measurement (p< 0.05). The FE ratio in the right lumbar erector spine muscle was significantly correlated with post-exercise trunk extension strength (p< 0.05). CONCLUSIONS: For patients with chronic lower back pain, stimulation of the lumbar extensor muscle and of proprioception is effective both for strengthening lumbar extensors and for improving the flexion-extension ratio. Consequently, forward leaning and supine bridge exercises with a suspension device are beneficial for normalising neuromuscular control of the erector spinae muscles.

Effect of the body mass index and sexual difference on the muscle activity during trunk exercise: a preliminary study.

There was lack of study which evaluated the effects of characteristics of subjects such as the body mass index (BMI) or waist circumference (WC), as well as sexual differences on trunk muscle activities. The purpose of the present study was to compare the abdominal muscle activities among the groups dividing criterion as the BMI, WC, and the gender. As a criterion of BMI and WC, subjects were arranged to three groups. Female subjects who were less than 25 kg/m2 BMI, and less than 90 WC were arranged as female with underweight group (FU), male subjects who were greater than 25 kg/m2 BMI and greater than 85 WC were arranged as male with overweight group (MO), male subjects who were less than 25 kg/m2 BMI and less than 85 WC were arranged in male with underweight group (MU). Surface electromyography responses of the rectus abdominis, internal oblique, external oblique muscles and lumbar level of erector spinae were obtained during the plank and maximal voluntary isometric contraction (MVIC). The MO group showed significantly higher %MVIC value of the internal oblique and lumbar level of erector spinae, compared to the MU group (P<0.05). The %MVIC of the rectus abdominis was significantly greater with the FU group (P<0.05). There were significant differences in the root mean squared (RMS) values from MVIC among the three groups (P<0.05). Regardless of muscles differences, the MO group showed significantly lower RMS activity values than the FU and the MU groups (P<0.05). Present study indicates some considerations of interpreting surface electromyography (sEMG) signal from region overlapping large fat tissue especially for trunk muscles. Individual characteristics such as gender, BMI, and WC could affect the sEMG signals. The female and male with overweight represent relatively high %MVICs during exercise, but it might be due to relatively low RMS values from procedure of MVICs.

Magnetic Fe@FeOx, Fe@C and α-Fe2O3 Single-Crystal Nanoblends Synthesized by Femtosecond Laser Ablation of Fe in Acetone.

There are few reports on zero-field-cooled (ZFC) magnetization measurements for Fe@FeOx or FeOx particles synthesized by laser ablation in liquids (LAL) of Fe, and the minimum blocking temperature (TB) of 120 K reported so far is still much higher than those of their counterparts synthesized by chemical methods. In this work, the minimum blocking temperature was lowered to 52 K for 4⁻5 nm α-Fe2O3 particles synthesized by femtosecond laser ablation of Fe in acetone. The effective magnetic anisotropy energy density (Keff) is calculated to be 2.7⁻5.4 × 105 J/m³, further extending the Keff values for smaller hematite particles synthesized by different methods. Large amorphous-Fe@α-Fe2O3 and amorphous-Fe@C particles of 10⁻100 nm in diameter display a soft magnetic behavior with saturation magnetization (Ms) and coercivities (Hc) values of 72.5 emu/g and 160 Oe at 5 K and 61.9 emu/g and 70 Oe at 300 K, respectively, which mainly stem from the magnetism of amorphous Fe cores. Generally, the nanoparticles obtained by LAL are either amorphous or polycrystalline, seldom in a single-crystalline state. This work also demonstrates the possibility of synthesizing single-crystalline α-Fe2O3 hematite crystals of several nanometers with (104), (113), (116) or (214) crystallographic orientations, which were produced simultaneously with other products including carbon encapsulated amorphous Fe (a-Fe@C) and Fe@FeOx core-shell particles by LAL in one step. Finally, the formation mechanisms for these nanomaterials are proposed and the key factors in series events of LAL are discussed.

Spontaneous Shape Alteration and Size Separation of Surfactant-Free Silver Particles Synthesized by Laser Ablation in Acetone during Long-Period Storage.

The technique of laser ablation in liquids (LAL) has already demonstrated its flexibility and capability for the synthesis of a large variety of surfactant-free nanomaterials with a high purity. However, high purity can cause trouble for nanomaterial synthesis, because active high-purity particles can spontaneously grow into different nanocrystals, which makes it difficult to accurately tailor the size and shape of the synthesized nanomaterials. Therefore, a series of questions arise with regards to whether particle growth occurs during colloid storage, how large the particle size increases to, and into which shape the particles evolve. To obtain answers to these questions, here, Ag particles that are synthesized by femtosecond (fs) laser ablation of Ag in acetone are used as precursors to witness the spontaneous growth behavior of the LAL-generated surfactant-free Ag dots (2⁻10 nm) into different polygonal particles (5⁻50 nm), and the spontaneous size separation phenomenon by the carbon-encapsulation induced precipitation of large particles, after six months of colloid storage. The colloids obtained by LAL at a higher power (600 mW) possess a greater ability and higher efficiency to yield colloids with sizes of <40 nm than the colloids obtained at lower power (300 mW), because of the generation of a larger amount of carbon 'captors' by the decomposition of acetone and the stronger particle fragmentation. Both the size increase and the shape alteration lead to a redshift of the surface plasmon resonance (SPR) band of the Ag colloid from 404 nm to 414 nm, after storage. The Fourier transform infrared spectroscopy (FTIR) analysis shows that the Ag particles are conjugated with COO⁻ and OH⁻ groups, both of which may lead to the growth of polygonal particles. The CO and CO2 molecules are adsorbed on the particle surfaces to form Ag(CO)x and Ag(CO2)x complexes. Complementary nanosecond LAL experiments confirmed that the particle growth was inherent to LAL in acetone, and independent of pulse duration, although some differences in the final particle sizes were observed. The nanosecond-LAL yields monomodal colloids, whereas the size-separated, initially bimodal colloids from the fs-LAL provide a higher fraction of very small particles that are <5 nm. The spontaneous growth of the LAL-generated metallic particles presented in this work should arouse the special attention of academia, especially regarding the detailed discussion on how long the colloids can be preserved for particle characterization and applications, without causing a mismatch between the colloid properties and their performance. The spontaneous size separation phenomenon may help researchers to realize a more reproducible synthesis for small metallic colloids, without concern for the generation of large particles.

Ridge Minimization of Ablated Morphologies on ITO Thin Films Using Squared Quasi-Flat Top Beam.

In this study, we explore the improvements in pattern quality that was obtained with a femtosecond laser with quasi-flat top beam profiles at the ablated edge of indium tin oxide (ITO) thin films for the patterning of optoelectronic devices. To ablate the ITO thin films, a femtosecond laser is used that has a wavelength and pulse duration of 1030 nm and 190 fs, respectively. The squared quasi-flat top beam is obtained from a circular Gaussian beam using slits with varying x-y axes. Then, the patterned ITO thin films are measured using both scanning electron and atomic force microscopes. In the case of the Gaussian beam, the ridge height and width are approximately 39 nm and 1.1 µm, respectively, whereas, when the quasi-flat top beam is used, the ridge height and width are approximately 7 nm and 0.25 µm, respectively.

Fully Solution-Processable Fabrication of Multi-Layered Circuits on a Flexible Substrate Using Laser Processing.

The development of printing technologies has enabled the realization of electric circuit fabrication on a flexible substrate. However, the current technique remains restricted to single-layer patterning. In this paper, we demonstrate a fully solution-processable patterning approach for multi-layer circuits using a combined method of laser sintering and ablation. Selective laser sintering of silver (Ag) nanoparticle-based ink is applied to make conductive patterns on a heat-sensitive substrate and insulating layer. The laser beam path and irradiation fluence are controlled to create circuit patterns for flexible electronics. Microvia drilling using femtosecond laser through the polyvinylphenol-film insulating layer by laser ablation, as well as sequential coating of Ag ink and laser sintering, achieves an interlayer interconnection between multi-layer circuits. The dimension of microvia is determined by a sophisticated adjustment of the laser focal position and intensity. Based on these methods, a flexible electronic circuit with chip-size-package light-emitting diodes was successfully fabricated and demonstrated to have functional operations.

Two Birds with One Stone: Spontaneous Size Separation and Growth Inhibition of Femtosecond Laser-Generated Surfactant-Free Metallic Nanoparticles via ex Situ SU-8 Functionalization.

Laser ablation in liquids (LAL) offers a facile technique to develop a large variety of surfactant-free nanomaterials with high purity. However, due to the difficulty in the control of the particle synthesis process, the as-prepared nanomaterials always have a broad size distribution with a large polydispersity (σ). Surfactant-free properties can also cause problems with particle growth, which further increases the difficulty in size control of the colloids. Therefore, searching for strategies to simultaneously unify the sizes of colloids and inhibit particle growth has become significantly important for LAL-synthesized nanomaterials to be extensively used for biological, catalytic, and optical applications, in which fields particle size plays an important role. In this work, we present a facile way to simultaneously realize these two goals by ex situ SU-8 photoresist functionalization. Ag nanoparticles (NPs) synthesized by femtosecond laser ablation of silver in acetone at laser powers of 300 and 600 mW were used as starting materials. The synthesized Ag NPs have a broad size distribution between 1 and 200 nm with an average size of ca. 5.9 nm and σ of 127-207%. After ex situ SU-8 functionalization and 6 months storage, most particles larger than 10 nm become aggregates and precipitate, which makes the size distribution narrow with an average diameter of 4-5 nm and σ of 48-78%. The precipitation process is accompanied by the decrease in colloid mass from the initial ∼0.2 to 0.10-0.11 mg after ex situ SU-8 functionalization and 6 months colloid storage. Morphology analysis indicates that ex situ SU-8 functionalization inhibits the particle growth into polygonal nanocrystals. Radical polymerization of SU-8 on Ag NPs is considered to be the reason for both spontaneous size separation and growth inhibition phenomena. Benefiting from Ag NPs embedment and acetone dissolution, the glass-transition temperature of SU-8 photoresist increased from 314 to 331 °C according to thermogravimetric analysis. The universality of ex situ SU-8 functionalization-induced growth inhibition and size separation behaviors is further proved using the Au colloids generated by LAL in acetone. This work is expected to provide a new route for better size control of LAL-synthesized colloids via ex situ photoresist functionalization, although a half of colloidal mass is wasted due to radical polymerization-induced colloidal precipitation.

Vibration-Assisted Femtosecond Laser Drilling with Controllable Taper Angles for AMOLED Fine Metal Mask Fabrication.

This study investigates the effect of focal plane variation using vibration in a femtosecond laser hole drilling process on Invar alloy fabrication quality for the production of fine metal masks (FMMs). FMMs are used in the red, green, blue (RGB) evaporation process in Active Matrix Organic Light-Emitting Diode (AMOLED) manufacturing. The taper angle of the hole is adjusted by attaching the objective lens to a micro-vibrator and continuously changing the focal plane position. Eight laser pulses were used to examine how the hole characteristics vary with the first focal plane's position, where the first pulse is focused at an initial position and the focal planes of subsequent pulses move downward. The results showed that the hole taper angle can be controlled by varying the amplitude of the continuously operating vibrator during femtosecond laser hole machining. The taper angles were changed between 31.8° and 43.9° by adjusting the vibrator amplitude at a frequency of 100 Hz. Femtosecond laser hole drilling with controllable taper angles is expected to be used in the precision micro-machining of various smart devices.

Immediate effect of stretching and ultrasound on hamstring flexibility and proprioception.

[Purpose] This research explored the positive effects of self-myofascial release on hamstring muscular flexibility and proprioception and investigated the effectiveness of the stretch combined with therapeutic ultrasound. [Subjects and Methods] This study included 30 healthy university students with no history of pain in the Achilles tendon or hamstring within the recent 6 months. Each participant completed two experiments. In the first experiment (MS), they completed self-myofascial stretching using a foam roller for 7 days. In the second experiment (MSU), the same participants performed the self-myofascial stretching after the 15-minute application of ultrasound. This study involved a pre- and post-test on hamstring muscle flexibility and hip joint proprioception. [Results] The use of self-myofascial stretching in the MS experiment had a significant effect on hamstring muscle flexibility and hip joint proprioception. However, the addition of ultrasound in the MSU experiment had no additive effect. [Conclusion] Self-myofascial stretching immediately increased hamstring muscle flexibility and improved hip joint proprioception, but the addition of pre-stretch ultra sound provided no further benefit.

The effect of cocontraction of the masticatory muscles during neck stabilization exercises on thickness of the neck flexors.

[Purpose] The purpose of this study was to determine the effect of the cocontraction of masticatory muscles during neck stabilization exercises on changes in the thickness of the neck flexors. [Subjects and Methods] Twenty subjects performed neck stabilization only exercise and neck stabilization exercise with simultaneous contraction of the masticatory muscles. Changes in the thickness of the longus colli and sternocleidomastoid were then measured by ultrasound. [Results] The thickness of the longus colli increased significantly fallowing cocontraction of the masticatory muscles and neck stabilization exercise, whereas the exercise method used had no significant effect on the thickness of the sternocleidomastoid. [Conclusion] Cocontraction of the masticatory muscles during neck stabilization exercise is helpful in increasing the thickness of longus colli muscle.

The comparison of the immediate effects of application of the suboccipital muscle inhibition and self-myofascial release techniques in the suboccipital region on short hamstring.

[Purpose] The purpose of this study was to research the effect of performing the suboccipital muscle inhibition (SMI) and self-myofascial release (SMFR) techniques in the suboccipital area on the flexibility of the hamstring. [Subjects] Fifty persons with short hamstrings participated in this research. According to the results of the finger-floor distance (FFD) test, the subjects were allocated to SMI and SMFR groups of 25 subjects each. [Methods] The SMI and SMFR techniques were applied to the groups. For the analysis, we used the FFD test and the straight leg raise (SLR) test for the flexibility of hamstring. The evaluator was blindfolded. [Results] In the SMI group, FFD, SLR, and PA were significantly changed after the intervention, and in the SMFR group, there was a significant change in SLR after the intervention. In a comparison between the groups, FED was found to be significantly increased in the SMI group. [Conclusion] Application of the SMI and SMFR to persons with short hamstrings resulted in immediate increases in flexibility of the hamstring. However, we could see that the SMI technique was more effective.

Effect of the Push-up Plus (PUP) Exercise at Different Shoulder Rotation Angles on Shoulder Muscle Activities.

[Purpose] Although the Push-Up Plus is a useful exercise method for shoulder stabilization, few studies have examined its effects at different angles of shoulder rotation. Therefore, the present study investigated the most effective exercise method for shoulder stabilization by analyzing muscle activities of the rotator cuff muscles at different angles of shoulder rotation. [Subjects] Fifteen healthy university students in their 20s were the subjects of this study. [Methods] Changes in muscle EMG related to shoulder stabilization were analyzed by performing the Push-Up Plus in shoulder positions of neutral, internal and external rotation. [Results] The highest muscle activity was found in external rotation, and in internal rotation the pectoralis major and levator scapula showed significantly lower activities than the other positions. [Conclusion] Selectively changing the rotation angle of the shoulder for different purposes of the shoulder exercise would be an effective exercise method.

Effect of smart phone use on dynamic postural balance.

[Purpose] The present study investigated what kind of effect smart phone use has on dynamic postural balance. [Subjects] The study subjects were 30 healthy students in their 20's who were recruited from a University in Busan, Korea. [Methods] The present experiment was quasi-experimental research which measured the postural balance (Biodex) of subjects while they sent text messages via smart phones in the standing position with the eyes open, and while they used two-way SNS. [Results] There were significant differences between standing and the dual-task situations. Among dual tasks using smart phones, SNS using situations showed the highest instability. [Conclusion] The use of smart phones in less stable conditions such as while walking or in moving vehicles should be discouraged.

The effects of precise contraction of the pelvic floor muscle using visual feedback on the stabilization of the lumbar region.

[Purpose] The purpose of this study is to verify whether precise contraction of the pelvic floor muscle (PFM) using visual feedback actually affects the thickness of abdominal muscles. [Subjects] The subjects were 29 healthy adults in their 20s who consented to participate in this study. [Methods] This study provided visual feedback on PFM using one ultrasound device and identified changes in the transversus abdominis (TRA) using another ultrasound device. Abdominal muscle thicknesses were measured by ultrasound under three conditions (rest, PFM contraction, PFM contraction with visual feedback). [Results] There were no statistically significant differences in the external oblique (EO) and internal oblique (IO) muscles between the measurements taken at rest and during the contraction of the PFM, and between those taken at rest and during the contraction of the PFM with visual feedback. There were significant differences in the TRA. In particular, TRA thickness was highest in the order of PFM contraction, PFM contraction with visual feedback, and rest. [Conclusion] Hollowing with visual feedback is not an efficient stabilization exercise method for the PFM.

Differences in Transversus Abdominis Muscle Function between Chronic Low Back Pain Patients and Healthy Subjects at Maximum Expiration: Measurement with Real-time Ultrasonography.

The purpose of the present study was to compare the contraction ability at maximum expiration of the transversus abdominis (TrA) in patients with chronic low-back pain (CLBP) with that of healthy individuals. [Subjects] We studied 15 patients with CLBP and 15 healthy subjects. The subjects were informed of the study's aim and methods, and the experiment was performed after obtaining the consent of the subjects. [Methods] The thickness of the abdominal muscles was measured using a LOGIQ Book XP (GE, USA). The main outcome variable was the ratio of TrA thickness at maximum expiration versus in the relaxed position (TrA activation ratio). [Results] There was a difference between the healthy subjects and the back pain subjects with regard to the thickness of the TrA at rest and the thickness of the muscle during contraction. However, there was no difference in the rate of change in the muscle activity. [Conclusion] In conclusion, CLBP patients exhibited atrophy of the TrA muscle, but voluntary TrA muscle activation was similar to that of the normal subjects.

Comparison of contraction rates of abdominal muscles of chronic low back pain patients in different postures.

[Purpose] This study examined the contraction rates of abdominal muscles in relation to the posture of chronic lumbar pain patients and normal subjects. [Subjects] The subjects were 17 chronic low back pain (CLBP) patients and 17 normal people between the ages of 20 and 59. [Methods] Experimental postures included a supine position, a sitting position, and a standing position. Measurements were taken at rest and during abdominal contraction. The measurement at rest was taken during expiration with comfortable breathing, and the measurement during contraction was taken at maximum expiration of forced expiration. Muscle contraction rates (on contraction and at relaxation) were calculated. [Results] There were significant differences between CLBP patients and normal subjects in the transversus abdominis (TrA) in the standing position. [Conclusion] Changes in contraction rates of the abdominal muscles of normal subjects and CLBP patients were examined in different postures at maximum expiration. It was found that the contraction rate of TrA in CLBP patients in a standing position, is significantly lower than that of normal subjects.

Log-scale dose response of inhibitors on a chip.

We demonstrate the accommodation of log-scale concentration gradients of inhibitors on a single microfluidic chip with a semidirect dilution capability of reagents for the determination of the half-inhibitory concentration or IC(50). The chip provides a unique tool for hosting a wide-range of concentration gradient for studies that require an equal distribution of measuring points on a logarithmic scale. Using Matrix metalloproteinase IX and three of its inhibitors, marimastat, batimastat, and CP471474, we evaluated the IC(50) of each inhibitor with a single experiment. The present work could be applied to the systematic study of biochemical binding and inhibition processes particularly in the field of mechanistic enzymology and the pharmaceutical industry.

A functionally separated nanoimprinting material tailored for homeotropic liquid crystal alignment.

In order to homeotropically align liquid crystals (LCs) at the nanosized surface grooves processed by nanoimprint lithography technology (NIL), we propose to design a hybrid-type homeotropic polymer material consisting of two distinct moieties with largely different thermo-mechanical properties and surface activity. Surface contact angle measurements and sum-frequency vibrational spectroscopy allow us to conclude that the polymer film is a functionally separated composite suitable for the homeotropic LC alignment processed by NIL. As one of the potential applications using the hybrid-type homeotropic polymer, we demonstrate that the nanoimprinted grooves at the polymer surface can achieve a zenithal nematic LC bistability.