Total Trajectory Length Research Articles

Effects of masticatory movements on the head, trunk and body sway during the standing position

Introduction Mastication involves complex tongue movements, coordination of lip, and cheek movements and is associated with head movement to facilitate the intraoral transport of food from ingesting to swallowing; it affects many functions of the whole body. However, studies to evaluate the relationship between masticatory movements and the body posture are still lacking to our knowledge. The purpose of this study was to characterize the effects of masticatory movements on the head, trunk, and body sway during the standing position. Methodology A total of 30 healthy subjects were evaluated. The MatScanTM system was used to analyze changes in body posture (center of foot pressure: COP) and the 3-dimensional motion analysis system was used to analyze changes in the head and trunk postures while subjects remained in the standing position with the rest position, centric occlusion, and masticating chewing gum. Results The total trajectory length of COP and head and trunk sways during masticating chewing gum were significantly shorter and smaller respectively than it was in the rest position and centric occlusion (p<0.016). COP area during masticating chewing gum was significantly smaller than it was in the 2 mandibular positions (p<0.016). Conclusion Masticatory movements positively affect the stability of the head, trunk, and body sways and enhance the postural stability during the standing position.

Multi-UAV Trajectory Planning for Energy-Efficient Content Coverage: A Decentralized Learning-Based Approach

In next-generation wireless networks, high-mobility unmanned aerial vehicles (UAVs) are promising to provide content coverage, where users can receive sufficient requested content within a given time. However, trajectory planning for multiple UAVs to provide content coverage is challenging since 1) UAVs cannot provide content coverage for all users due to the limited energy and caching storage, and 2) the trajectory planning of UAV is coupled with each other. Moreover, the complete information based trajectory planning methods are unusable since UAVs cannot obtain prior information on the rapidly changing environment. In this paper, we investigate the multi-UAV trajectory planning for energy-efficient content coverage. We first formulate an energy efficiency maximization problem considering recharging scheduling, which aims to reduce the total length of trajectories of UAVs under the quality of service (QoS) constraints. To settle environment uncertainty, the trajectory planning problem is modeled as two coupled multi-agent stochastic games, whose equilibrium constitute the optimal trajectory. To obtain the equilibrium, we propose a decentralized reinforcement learning algorithm, which can decouple the two games. We prove that the proposed algorithm can converge to the optimal solution of the Bellman equation with a higher rate compared to the centralized one. Moreover, simulation results show that the energy efficiency of the proposed algorithm is smaller than 5% compared the optimal, which is obtained with the prior information of environments.

Effects of Lower Limbs Exercise with Light and Heavy Loads on the Center of Gravity Sway

Background: Fatigue to the lower limbs due to exercise load affects the center of gravity sway (COGS) during standing, and the greater the load, the greater the COGS. Research Question: Do different exercise loads to the lower limbs have an effect on the COGS and does sitting/resting promote recovery after exercise. Methods: The subjects were 30 healthy young men. The COGS after light and heavy load exercises was compared after a 3-min sitting/resting period before and after the load exercises. For each test, the COGS was measured for 30 s. Bicycle pedaling for 30 s with loads of 1% (light load) and 7.5% (heavy load) of body weight was selected as the load exercise for the lower limbs. The x-axis and y-axis trajectory lengths, total trajectory length, outer peripheral area, and rectangular area were selected as variables affecting the COGS. Results: Repeated measures analysis of variance clarified that of all variables, COGS after heavy load exercises was significantly greater than that after light load exercises and during standing after sitting/resting. However, there was no significant difference in COGS after light load exercise and during standing. Significance: The COGS after heavy load exercise was greater than that after light load exercise. The light load exercise used in this study had no effect on COGS in young men. Even after heavy load exercise, the COGS recovered after a 3-min sitting/resting period.

Hallux valgus deformity and postural sway: a cross-sectional study

BackgroundHallux valgus deformity has been reported to be associated with increased postural sway. However, the direction and magnitude of postural sway associated with hallux valgus remain inconclusive. We assessed the association between hallux valgus deformity and postural sway using a force plate.MethodsThe subjects were 169 healthy volunteers, > 40 years old (63 males, 106 females, average age: 66.0 ± 12.4 years old), who took part in an annual medical examination. We investigated the photographic hallux valgus angle (°), total trajectory length of the gravity center fluctuation (mm), area of the center of pressure (mm2), mediolateral and anteroposterior postural sway (mm) in a standing position with 2-legged stance and eyes open, hallux pain (Numerical Rating Scale), trunk and lower limb muscle mass (kg). We classified the subjects into a hallux valgus group (n = 44, photographic hallux valgus angle of 1 or both feet ≥ 20°) and a no hallux valgus group (n = 125, photographic hallux valgus angle of both feet < 20°) and analyzed the relationship between hallux valgus and postural sway.ResultsThe anteroposterior postural sway in the hallux valgus group (6.5 ± 2.8) was significantly greater than in the no hallux valgus group (5.4 ± 2.2, p = 0.014), and the lower limb muscle mass in the hallux valgus group (12.4 ± 2.2) was significantly smaller than in the no hallux valgus group (13.5 ± 3.2, p = 0.016). The total value of the photographic hallux valgus angle on both feet was positively correlated with the anteroposterior postural sway (p = 0.021) and negatively correlated with the lower limb muscle mass (p = 0.038). The presence of hallux valgus (p = 0.024) and photographic hallux valgus angle (p = 0.008) were independently related to the magnitude of anteroposterior postural sway.ConclusionsHallux valgus deformity and its severity were positively associated with the magnitude of the anteroposterior postural sway.Trial registration2017 − 135. Registered 22 August 2017.

Optimization design method for the bypass trajectories of infill adjustment wells in the fracturing areas of shale gas fields

In the design of a shale-gas cluster horizontal well, it is necessary to consider the bypass of the fracturing influence domains of existing wells and the interference between fracturing influence domains when the wellbore trajectories of infill adjustment wells in the fracturing areas are designed. In order to quickly evaluate the rationality of the design scheme of fracturing wellbore trajectory in an infill adjustment well, this paper adopted the vector algebra method to build a geometric model of the obstacles in the shale gas fracturing area. In this geometric model, the influence domains of hydraulic fractures are taken into account. Then, based on this geometric model, the optimization design model of bypass trajectory in the shale gas fracturing area was established by taking the minimization of total trajectory length and trajectory potential energy as the optimization objective and the anti-collision between trajectories as the constraint. Besides, the geometric check method to judge if there is any interference between fracturing influence domains was provided. Finally, the established optimization design model was verified based on the actual drilling data of Fuling Shale Gas Field in the Sichuan Basin. And the following research results were obtained. First, the obstacle sizes in fracturing areas will be seriously underestimated if the fracturing influence domains are neglected. Second, if the fracturing influence domains are neglected, the designed bypass trajectory can bypass the wellbore trajectories of old wells, but may intersect the fracturing influence domains of existing wells, thus inducing drilling accidents. In conclusion, the proposed optimization design model of bypass trajectory in the shale gas fracturing area can satisfy the constraint of anti-collision and bypass and achieve the optimization objective of minimizing total trajectory length and trajectory potential energy, and the corresponding design calculation avoids complex calculation and check.

An Autonomous, Optically-Powered, Direct-to-Digital Sun-Angle Recorder for Honey Bee Flight Tracking

An autonomous sensor for insect flight tracking that captures and stores solar angle-of-incidence without the use of a conventional ADC is presented. The chip uses pairs of Angle-Sensitive Pixels as differential 1-bit ADCs, and an array of these sensors provides a many-bit encoding of angle-of-incidence. Digitization occurs immediately within the pixel by use of a novel in-pixel comparator, thus enabling ultra-low-power, direct-to-digital capture of angle-of-incidence. These measurements are stored in an on-chip memory throughout the flight and can be uploaded to a base station via magnetic backscatter at the end of the flight. To permit full autonomy, the system is powered by on-chip photovoltaics, providing open-circuit voltages in the range of 0.40 − 0.50 V in natural sunlight, the intensity of which can vary throughout a flight. The system consumes a simulated 630nW at nominal supply voltage of 0.45 V, and circuit topologies amenable to photovoltaic power conditions are presented. The chip is envisioned as a flight recorder to be mounted on honey bees to track their trajectories, and bee flights were emulated by carrying the chip along a 226 m outdoor trajectory and downloading the recorded flight data from the chip at a base station in the field. Across 18 trials of the same trajectory, which emulates a small sample of tagged bees visiting known feeding sites and returning to their hive, the average reconstructed final position is 9.6 m away from the true final position, an error less than 5% of the total trajectory length.

Effects of Long-Term Use of Insoles with a Toe-Grip Bar on the Balance, Walking, and Running of Preschool Children: A Randomized Controlled Trial.

This randomized controlled study is aimed at investigating the effects of long-term use of insoles with a toe-grip bar on the balance, walking, and running of preschool children. Fifty-two preschool children were randomly assigned to an intervention group or control group. Children included in the intervention group wore shoes with insoles that had a toe-grip bar, and those in the control group wore shoes with regular insoles without a toe-grip bar for 4 weeks while they were at school. The center of gravity sway (total trajectory length and envelope area), walking parameters (walking speed, cadence, stride length, step length, stance time, and swing time), and time to run 25 m were measured before and after the intervention. The 25 m running time of the intervention group was significantly improved after the intervention (F = 5.66; p < 0.05). This study suggests that insoles with a toe-grip bar may contribute to improvements in the running of preschool children.

Relationship between Dynamic Trunk Balance and the Mini-Balance Evaluation Systems Test in Elderly Women

Objectives: Among elderly individuals, falls are major contributors to becoming bedridden, and evaluating and preventing the risk of falls is thus important in the elderly. Trunk balance stability is important to prevent falling. To safely measure trunk balance function, we have developed a dynamic balance-measurement device that is used with the subject in a sitting position. This Mini-Balance Evaluation Systems Test (Mini-BESTest) is a simple balance evaluation test that appears useful for detecting problems with balance function. The purpose of this study was to examine the relationship between dynamic trunk balance and findings on the Mini-BESTest in elderly women. Methods: Participants comprised 31 healthy women >60 years old. Evaluation items were the Mini-BESTest total score; dynamic sitting balance, static postural balance, and muscle strength (back muscle, iliopsoas muscle, and quadriceps). Results: Mean total Mini-BESTest score was 21.1. Mean dynamic sitting balance measured as total center of gravity (COG) trajectory length was 1447.5 mm. A negative correlation (r=-0.382, p=0.034) was observed between total COG trajectory length and BESTest score. No correlations were evident between total COG trajectory length, stationary standing COG, and muscle strength. Conclusion: In elderly women, trunk balance in dynamic sitting correlated negatively with total Mini-BESTest score.

Effect of Toe Type on Static Balance in Ballet Dancers.

Some forefoot shapes are ideal for pointe work in ballet. Egyptian-type, with the hallux being longest and the remaining toes decreasing in size, and Greek-type, with the second toe longer than the hallux, are considered less optimal for pointe work. Square-type, with the second toe the same length as the hallux, is considered optimal. This study compared postural stability in the bipedal stance, demi pointe, and en pointe between ballet dancers with the two toe types using a stabilometer. This study included 25 Japanese ballet academy dancers who had received ballet lessons for at least 6 years. Toes were categorized into Egyptian-type (n=14) and square-type (n=11). Bipedal stance, demi pointe, and en pointe were tested. Center of pressure (COP) parameters were calculated from ground-reaction forces using two force plates: total trajectory length (LNG), velocities of anterior-posterior (VAP) and medial-lateral directions (VML), and maximum range displacement in the anterior-posterior (MAXAP) and medial-lateral directions (MAXML). Mann-Whitney U-tests were used to examine differences in COP parameters. There were no differences in parameters during bipedal stance or demi pointe. However, dancers with Egyptian-type toes had significantly greater LNG (p<0.01), VML (p=0.01), MAXML (p<0.01), and MAXAP (p=0.03) during en pointe. Ballet dancers with Egyptian-type toes demonstrated greater displacement in the medial-lateral and anterior-posterior directions during en pointe. Ballet dancers should be aware of toe types and sway character to optimize ballet training and balance.

Covering orthogonal polygons with sliding k-transmitters

In this paper, we consider a new variant of covering in an orthogonal art gallery problem where each guard is a sliding k-transmitter. Such a guard can travel back and forth along an orthogonal line segment, say s, inside the polygon. A point p is covered by this guard if there exists a point q∈s such that pq‾ is a line segment normal to s, and has at most k intersections with the boundary walls of the polygon. The objective is to minimize the sum of the lengths of the sliding k-transmitters to cover the entire polygon. In other words, the goal is to find the minimum total length of trajectories on which the guards can travel to cover the entire polygon. We prove that this problem is NP-hard when k=2, and present a 2-approximation algorithm for any fixed k≥2. The proposed algorithm also works well for an orthogonal polygon where the edges have thickness.

Relationship between Dynamic Trunk Balance and the Balance Evaluation Systems Test in Elderly Women.

ABSTRACTObjectiveFalls are major contributors to elderly subjects becoming bedridden. Consequently, it is important to evaluate and minimize the risk of falls in the elderly. Trunk stability is important for balance function and is related to fall prevention in elderly women. We developed a balance-measuring device that uses a dynamic sitting position to safely measure balance function. The Balance Evaluation Systems Test (BESTest) is useful method to assess balance function, a recently developed balance evaluation test that can detect minor balance problems not captured by previous tests. The purpose of the present study was to examine the relationship between dynamic trunk balance and findings of the BESTest in elderly women. MethodsThirty-one healthy women aged 60 years or more participated in this study. The evaluation items were the BESTest total score, scores for each of the six elements of the BESTest, dynamic sitting balance, static postural balance, and muscle strength. ResultsThe mean total BESTest score was 85.4 points. The mean total trajectory length of the center of gravity (COG) during the dynamic sitting balance test was 1447.5 mm. A negative correlation (r=–0.481, P= 0.006) was observed between the total COG trajectory length and the BESTest score. A negative correlation was also found between the total COG trajectory length and biomechanical constraints (r=–0.492, P=0.005) and anticipatory postural adjustments (r=–0.532, P=0.002). There were no correlations between the dynamic sitting balance total COG trajectory length and the stationary standing COG trajectory length or muscle strength. ConclusionsIn elderly women, the total COG trajectory length during dynamic sitting was negatively correlated with the BESTest total score.

Noncausal trajectory optimization for real-time range-only target localization by multiple UAVs

This study proposes a new method namely noncausal trajectory optimization which is developed to obtain superior performance in range-only (i.e. distance and received signal strength based) target localization by multiple unmanned aerial vehicles (UAVs). Noncausal trajectory optimization suggests to optimize the next waypoint considering not only the past waypoints already visited but also the future remaining trajectory of the UAV. Therefore, based on the analogy of noncausal filters in signal processing, the new proposed method is named as “noncausal trajectory optimization”. In the previous literature, because only the past trajectory is taken into account, the UAVs are mostly suggested to make circular or spiral motions around the target. However, this study suggests that the UAV must create a linear trajectory as much as possible when total travel length is shorter than initial distance to the target. For a single UAV, this study proves that the ideal direction of this linear path is only the function of the ratio of the total length of trajectory over the initial distance to the target. To prove this, the summation operators in Fisher information matrices (FIM) are converted to line integrals and then D-optimality criterion is applied. Next, noncausal trajectory optimization is introduced which is dedicated to obtain a higher final localization capability by sacrificing immediate or early advantages. Then, noncausal joint trajectory optimization for multiple UAVs is illustrated. Finally, trajectory optimization for moving target as well as three dimensional trajectory optimization are discussed. Monte Carlo simulations showed that the proposed optimization method obtains a higher final accuracy level compared to the ordinary trajectory optimization.

T vector velocity: A new ECG biomarker for identifying drug effects on cardiac ventricular repolarization.

BackgroundWe present a new family of ECG biomarkers for assessing drug effects on ventricular repolarization. We show that drugs blocking inward (depolarizing) ion currents cause a relative increase of the T vector velocity (TVV) and accelerate repolarization, while drugs blocking outward ion currents cause a relative decrease of the TVV and delay repolarization. The results suggest a link between the TVV and the instantaneous change of the cellular action potentials that may contribute to bridge the gap between the surface ECG and myocardial cellular processes.MethodsWe measure TVV as the time required to reach X% of the total Trajectory length of the T vector loop, denoted as TrX. Applied to data from two FDA funded studies (22+22 subjects, 5232+4208 ECGs) which target ECG effects of various ion-channel blocking drugs, the TrX effect profiles indicate increasingly delayed electrical activity over the entire repolarization process for drugs solely reducing outward potassium current (dofetilide, moxifloxacin). For drugs eliciting block of the inward sodium or calcium currents (mexiletine, lidocaine), the TrX effect profiles were consistent with accelerated electrical activity in the initial repolarization phase. For multichannel blocking drugs (ranolazine) or drug combinations blocking multiple ion currents (dofetilide + mexiletine, dofetilide + lidocaine), the overall TrX effect profiles indicate a superposition of the individual TrX effect profiles.ResultsThe parameter Tr40c differentiates pure potassium channel blocking drugs from multichannel blocking drugs with an area under the ROC curve (AUC) of 0.90, CI = [0.88 to 0.92]. This is significantly better than the performance of J-Tpeakc (0.81, CI = [0.78 to 0.84]) identified as the best parameter in the second FDA study. Combining the ten parameters Tr10c to Tr100c in a logistic regression model further improved the AUC to 0.94, CI = [0.92 to 0.96].ConclusionsTVV analysis substantially improves assessment of drug effects on cardiac repolarization, providing a plausible and improved mechanistic link between drug effects on ionic currents and overall ventricular repolarization reflected in the body surface ECG. TVV contributes to an enhanced appraisal of the proarrhythmic risk of drugs beyond QTc prolongation and J-Tpeakc.

The effects of combined static and dynamic stretching of anti-gravitational muscles on body flexibility and standing balance: A preliminary study of healthy young participants

IntroductionFalling is a leading cause of injury-related death. Previous studies reported that an impairment of standing balance is one of the causative factors associated with falling. The combined use of static and dynamic stretching has been reported as a treatment method for improving standing balance. As one of the combined methods, stretching based on Mézières’ concept, which has an efficacy on the improvement of body flexibility, has been used. However, it is not fully clear whether stretching based on Mézières’ concept can improve standing balance. This study aimed to examine the effects of combined method of static and dynamic stretching of anti-gravitational muscles based on Mézières’ concept on body flexibility and standing balance. MethodsThis study employed a quasi-randomized controlled trial design. Thirteen subjects were assigned randomly to one of two groups: stretching or control. A sit and reach test (SRT), functional reach test (FRT), and total trajectory length of center of pressure (COP) during static standing were assessed at pre- and post-intervention. An independent t-test was used to compare the rate of improvement between both groups at each assessment. ResultsThe stretching group demonstrated a significantly larger rate of improvement in the total trajectory length of COP compared to the control group. In the SRT and FRT, the stretching group showed a trend toward improvement compared to the control group, but did not achieve statistical significance. ConclusionsThe combined use of static and dynamic stretching of anti-gravitational muscles might have the potential to improve the standing balance.

Multi-objective cellular particle swarm optimization for wellbore trajectory design

Wellbore trajectory design is a determinant issue in drilling engineering. The criteria to evaluate a wellbore trajectory are summarized as the total trajectory length, the torque and the well profile energy in this paper. By minimizing the wellbore trajectory length, torque and profile energy simultaneously, it is most likely that a wellbore trajectory designed to arrive at the specific target can be drilled more safely, quickly and cheaply than other potential trajectories. However, these three objectives are often in conflict with each other and related in a highly nonlinear relationship. A multi-objective cellular particle swarm optimization (MOCPSO) with an adaptive neighborhood function is developed in this paper. Then, MOCPSO is applied with the three objective functions to gain a set of Pareto optimal solutions that are beneficial for a less risky and less costly wellbore trajectory design option. Besides, MOCPSO’s performance is compared with multi-objective PSO, multi-objective evolutionary algorithm based on decomposition (MOEA/D) and non-dominated sorting genetic algorithm-II (NSGA-II). Effect of the proposed neighborhood function is also investigated by making contrasts with the commonly used four neighborhood templates. Moreover, the radius parameter in the adaptive neighborhood function is analyzed to reveal its influence on the optimization performance. It can be inferred that MOCPSO is statistically superior to both multi-objective PSO, NSGA-II and MOEA/D at the 0.05 level of significance on the wellbore trajectory design problem. And the proposed adaptive neighborhood function performs either comparable or better as compared to the other commonly used neighborhood functions. According to the parameter analysis, it can be concluded that the MOCPSO approach with radius value of 1or 1.5 has a better statistical performance.

P2-5-09. Effect of transcranial direct current electrical stimulation on supplementary motor cortex on control of balance in healthy subjects

Use of transcranial direct current electrical stimulation (tDCS) in rehabilitation has been reported, but few on the effects of tDCS on posture and balance. Our objective was to clarify the influence of tDCS of the supplementary motor area (SMA) on balance in healthy people. Eight healthy adults (4 males, 4 females, mean age 25 yrs) who gave informed consent were enrolled. For tDCS, the anode was attached by tape to the scalp above the SMA, likewise and the cathode was placed at the external occipital protuberance., and Stimulation at intensity of 1 mA was applied for 20 min. The same procedure without stimulation was followed for sham stimulation. Before and after stimulation subjects performed raising of upper limbs while standing, and maintaining a single leg standing position, on a stabilometer. Items evaluated were shortening of the total trajectory length of the center of gravity movement during and after raising the upper limbs before and after the stimulation, and shortening of the total trajectory length of the center of gravity movement during maintaining the single posture. It is thought that tDCS anodic stimulation of the SMA promoted the posture adjustment function of SMA and contributed to a decrease in center of gravity fluctuation.

Trunk Balance Evaluation in Adolescent Athletes and Gender Difference using the Dynamic Sitting Balance Device

Objective: The purpose of this study was to quantitatively measure the trunk stability of adolescent athletes using a recently developed, plane-specific, dynamic trunk stability measuring device and to examine gender differences. Methods: This was a cross-sectional study to confirm the difference in dynamic trunk stability between male and female adolescent athletes ranging in age from 12 to 15 years. 15 adolescent athlete cohort was divided into 2 groups by gender. In the dynamic trunk balance evaluator that we developed, the seating surface can be vibrated at a constant cycle (0.2 Hz, 0.4 Hz, 0.6 Hz), the pressure of the seating surface under vibration is detected by three small force sensors installed under the seating surface, and the center of pressure (COP) can be calculated. Measurements were performed for 30 s by one examiner, and each participant was measured three times after two practice attempts. While the seating surface was swaying, the participant's gaze was fixed to a mark about 1 cm in diameter set at a position 2 m in front of the participant at eye height, and the participant was asked to maintain the position of the head constant. The fluctuation of the center of gravity on the seat surface over time was measured, and the total trajectory length of the COP was used as the evaluation item. Results: There were no adverse events during measurement. The results for the total COP trajectory length of male was 2365 ± 176 mm, and that of female was 2674 ± 293 mm. There were significant differences between the male and female groups. In particular, Adolescent female athletes had less dynamic trunk stability in the coronal plane. Conclusion: Adolescent female athletes had less dynamic trunk stability in the coronal plane than their male counterparts. The recently developed device may be a useful tool for assessing the effects of prevention programs on dynamic core stability.

A Study on changes to the body by changing the thickness of the insole (sole plate)

We have spent to walk the majority of the activities of daily living. We can reduce the burden on the foot by putting insoles in the shoes. In addition, insoles are used as part of rehabilitation. It can be proposed for the maintenance of a healthy life by studying the effect on the body due to the shape of the insole. This study focused on the thickness of the insoles and aimed to clarify the influence on the body when to use different insoles of the toe portion and the heel portion. Experimental subjects were opened with resting stance posture, both feet standing position and one-foot standing position. The condition of the insole was 5.5 ㎜ and 7.5 ㎜ in the thickness of the toes, and the heels were 5.0 ㎜ and 7.5 ㎜ in thickness. The experimental participants were four men in their twenties. The measuring device was a force plate. The sampling rate was 1000 Hz. From the result of the total trajectory length, it was confirmed that the center of gravity fluctuation becomes smaller by the insole.

Effect of gaze-stabilization exercises on vestibular function during postural control.

Gaze-stabilization exercise (GSE) is often conducted in vestibular rehabilitation, but its effect on vestibular function in postural control is not clear. We investigated whether GSE affects vestibular function during static upright standing and vestibulospinal reflex (VSR) in healthy young adults. First, the center of pressure of the total trajectory length (CoP-L) was measured before each GSE task or control (only standing) task (pre), immediately after (post), and 10 min after (post10) in the static standing position on foam rubber with the eyes open or closed (EC). Second, the H-reflex on the soleus muscle was measured after the onset of ipsilateral anodal galvanic vestibular stimulation before and after a GSE or a control task to estimate the amount of VSR induced by electrical vestibular input. CoP-L for the pre, post, and post10 control tasks and the GSE in EC did not differ significantly; the CoP-L for the post and post10 tasks in EC were significantly lower than that for the pretask. The H-reflex was inhibited by galvanic vestibular stimulation in the pre-GSE tasks. The inhibition increased after GSE, but not during control tasks. These findings suggest that GSE immediately improves the postural stability required for vestibular function and can be mediated by VSR improvements.

Effect of Insoles with a Toe-Grip Bar on Toe Function and Standing Balance in Healthy Young Women: A Randomized Controlled Trial.

Objective The aim of this randomized controlled study was to investigate the effects of insoles with a toe-grip bar on toe function and standing balance in healthy young women. Methods Thirty female subjects were randomly assigned to an intervention group or a control group. The intervention group wore shoes with insoles with a toe-grip bar. The control group wore shoes with general insoles. Both groups wore the shoes for 4 weeks, 5 times per week, 9 hours per day. Toe-grip strength, toe flexibility, static balance (total trajectory length and envelope area of the center of pressure), and dynamic balance (functional reach test) were measured before and after the intervention. Results Significant interactions were observed for toe-grip strength and toe flexibility (F = 12.53, p < 0.01; F = 5.84, p < 0.05, resp.), with significant improvement in the intervention group compared with that in the control group. Post hoc comparisons revealed that both groups showed significant improvement in toe-grip strength (p < 0.01 and p < 0.05, resp.), with higher benefits observed for the intervention group (p < 0.01). Conversely, no significant interaction was observed in the total trajectory length, envelope area, and functional reach test. Conclusions This study suggests that insoles with a toe-grip bar contribute to improvements in toe-grip strength and toe flexibility in healthy young women.