Swing Motion Research Articles

Deep Brain Stimulation and Levodopa Affect Gait Variability in Parkinson Disease Differently

BackgroundBoth dopaminergic medication and subthalamic nucleus (STN) deep brain stimulation (DBS) can improve the amplitude and speed of gait in Parkinson disease (PD), but relatively little is known about their comparative effects on gait variability. Gait irregularity has been linked to the degeneration of cholinergic neurons in the pedunculopontine nucleus (PPN). ObjectivesThe STN and PPN have reciprocal connections, and we hypothesized that STN DBS might improve gait variability by modulating PPN function. Dopaminergic medication should not do this, and we therefore sought to compare the effects of medication and STN DBS on gait variability. Materials and MethodsWe studied 11 patients with STN DBS systems on and off with no alteration to their medication, and 15 patients with PD without DBS systems on and off medication. Participants walked for two minutes in each state, wearing six inertial measurement units. Variability has previously often been expressed in terms of SD or coefficient of variation over a testing session, but these measures conflate long-term variability (eg, gradual slowing, which is not necessarily pathological) with short-term variability (true irregularity). We used Poincaré analysis to separate the short- and long-term variability. ResultsDBS decreased short-term variability in lower limb gait parameters, whereas medication did not have this effect. In contrast, STN DBS had no effect on arm swing and trunk motion variability, whereas medication increased them, without obvious dyskinesia. ConclusionsOur results suggest that STN DBS acts through a nondopaminergic mechanism to reduce gait variability. We believe that the most likely explanation is the retrograde activation of cholinergic PPN projection neurons.

Energy Harvester Based on an Eccentric Pendulum and Wiegand Wires.

This study proposed an energy harvester that combines an eccentric pendulum with Wiegand wires to harvest the kinetic energy of a rotating plate. The energy harvester converts the kinetic energy into electrical energy to power sensors mounted on the rotating plate or wheel. The kinetic model is derived from the Euler–Lagrange equation. The eccentric pendulum generates a swing motion from the direction variation of the centrifugal force and the gravitational force. The magnetic circuit is designed such that, during the swing motion, an alternating magnetic field is formed to induce the output voltage of the Wiegand wire. COMSOL software was used to simulate magnetic flux density and optimize the geometric parameters of magnets. Response surface methodology was used to formulate the output voltage model. Magnetic flux density affects output voltage dramatically. However, the output voltage is not sensitive to the gradient of magnetic flux density. The experimental results indicate that when the Wiegand wire is 14.2 mm from the magnet, the generation power is 0.118–1.15 mW, in a speed range of 240–540 rpm. When the Wiegand wire is 7.0 mm from the magnet, the generation power is 0.741–1.06 mW, in a speed range of 480–660 rpm.

Development and Evaluation of a Passive Mechanism for a Transfemoral Prosthetic Knee That Prevents Falls during Running Stance

Existing prosthetic knees used by transfemoral amputees have function almost akin to non-friction hinge joints during the running stance phase. Therefore, transfemoral amputees who wish to run need sufficient strength in their hip extension muscles and appropriate prosthetic leg swing motion to avoid falling due to unintended prosthetic knee flexion. This requires much training and practice. The present study aimed to develop a passive mechanism for a transfemoral prosthetic knee to prevent unintended prosthetic knee flexion during the running stance phase. The proposed mechanism restricts only flexion during the prosthetic stance phase with a load on the prosthetic knee regardless of the joint angle of the prosthetic knee. The load on the prosthetic knee required to maintain locked flexion was analyzed. We developed a rough prototype and conducted an evaluation experiment with an intact participant attached to a simulated prosthetic limb and the prototype. The results of level walking showed that the proposed mechanism limits knee flexion, as designed. The results of the preliminary trial suggest that the proposed mechanism functions appropriately during running, where the load on the prosthetic knee is larger than that during walking.

Friction of Fluoroplastic Coatings in Swinging Motion

Friction of Fluoroplastic Coatings in Swinging Motion

A Novel Fish-Inspired Robot with a Double-Cam Mechanism

Fishes have evolved different excellent swimming strategies. To study the influence of tail fin swing on the swimming performance of bionic robot fish, with one joint under the same tail swing frequency and amplitude, we designed a novel robot fish, driven by a double-cam mechanism. By designing the profile of the cam in the mechanism, the robot fish can achieve different undulatory motion trajectory of the caudal fin under the same tail swing frequency and amplitude. The mechanism simulated the undulatory motion of crucian carp. We studied the influence of undulatory motion on the swimming speed of robot fish, which was analyzed by dynamic analysis of the undulatory motion and experiments. According to the experimental results, we can find that the swimming speed of the robotic fish is different under various wave motions. When other conditions are the same, the speed that the robot fish can achieve by imitating the swing motion of the real fish is 1.5 times that of the robot fish doing the cycloid motion. The experimental results correspond to the kinetic analysis results. Furthermore, it is proven that the robot fish with a low caudal peduncle stiffness swims faster under a low swinging frequency, and the speed of a robot fish with a high caudal peduncle stiffness is higher under a high tail swinging frequency.

Pool boiling enhancement via nanotexturing and self-propelled swing motion for bubble shedding

Vapor bubbles were shed from the heater surface by self-propelled swinging resulting from rising bubbles for improved heat dissipation. The heating wire was electroplated, and thus nanocones were formed on its surface. This nanotextured wire was attached to polyamide tape and underwent Joule heating. The vapor bubbles on the wire induced the self-propelled motion of the heater plates assembled in a “Λ” shape suspended at the tip. The growing bubbles experienced competing forces in the form of buoyancy and surface tension. Eventually, buoyancy dominated and, as a result, the heater plate was propelled in the direction of the rising bubbles. The nanotextured surface increased the number of bubble nucleation sites, and thus, the displacement of the swing motion was magnified accordingly, owing to enhanced bubble detachment. The sustainable swing motion was motorized to enable the temperature of the wire heater to be accurately measured. In these motorized experiments, the critical heat flux (CHF) and effective convective heat transfer coefficient (heff) increased when the amount of nanotexturing on the heating wire increased, which confirmed the benefits of nanotexturing on pool boiling in which self-propelled swing motion was utilized to shed the nucleated bubbles.

Mechanism and Effect of Tread Swing for Lower Limbs Strength Training Device

The aim of this study was to propose a tread swing mechanism for lower-limb strength training devices and to confirm its effects. In the standing position and for training the lower limbs, if the tread-surface angle is inappropriate, the posture of the knee joints gets affected, and knee adduction/valgus moments, which result in knee stress, get generated. The target training exercises are the front-back leg scissors and open-close leg triangle exercises. With regard to the swing of the tread, it is necessary to realize a pitch/yaw rotation and a roll/yaw rotation for the former and the latter exercises, respectively. As a result, knee joint stress can be reduced by moving the center of pressure (COP). The proposed mechanism has a further differential mechanism that utilizes the difference between the pulley diameters. The translational movement force of the tread is transmitted as the torque of the swing motion for the pitch, roll, and yaw through the effects of a differential mechanism. The rate of the swing angle can be changed by adjusting the pulley diameter. As a result of evaluating the effect of exercises using a manufactured device, it was confirmed that the tread performed a predetermined swing motion. It was also confirmed that the COP position changed. Therefore, it is expected that knee joint stress will reduce. Rehabilitation and strength training that result in small knee joint stresses and generate large muscle load are in great demand for people experiencing knee joint failure.

Microbial transport and dispersion in heterogeneous flows created by pillar arrays

Swimming microbes, such as bacteria and algae, live in diverse habitats including soil, seawater, and the human body. The habitats are characterized by structural boundaries and heterogeneous fluid flows. Although in recent decades much progress has been made in understanding the Brownian ratchet motion of microbes and their hydrodynamic interactions with the wall, the complex interplay between the structural and fluid environment with self-propelling microbial motion still remains elusive. Here, we developed a Langevin model to simulate and investigate the transport and dispersion of microbes in periodic pillar arrays. By tracing the spatiotemporal evolution of microbial trajectories, we show that a no-slip pillar surface induces local fluid shear, which redirects microbial movements. In the vicinity of pillars, looping trajectories and slow motion lead to a transient accumulation and sluggish transport of microbes. Several modes of microscopic motion, including swinging, zigzag, and adhesive motion, were observed. In an asymmetric pillar array, adjacent downstream pillars provide geometric guidance such that the microbial population has a deterministic shift perpendicular to the flow direction. Moreover, the effects of the topology of the pillar array, fluid flow properties, and microbial properties on microbial advection and dispersion in a pillar array were quantitatively analyzed. Our results highlight the importance of surrounding structures and flow on microbial transport and distribution, and these should be carefully considered in the study of microbial processes.

Bio-inspired bistable piezoelectric energy harvester for powering animal telemetry tags: Conceptual design and preliminary experimental validation

This paper presents the conceptual design, preliminary experimental validation, and performance evaluation of a novel bio-inspired bi-stable piezoelectric energy harvester for self-powered animal telemetry tags. The overall conceptual design, which includes a bio-inspired attachment and a bi-stable piezoelectric energy harvester, is introduced firstly with a specific application example of marine fish tracking. The self-powered telemetry tag can be externally deployed on fish (dorsal fin) to monitor fish habitats, population, and underwater environment. Inspired by the Venus flytrap's rapid shape transition, a bi-stable piezoelectric energy harvester is developed to scavenge energy from fish maneuvering and the surrounding fluid flow for a sustainable power supply. The bistability of the harvester is characterized by the measured force-displacement curve and double potential wells. A bluff body is integrated to the free end of the bistable piezoelectric energy harvester to enhance the structure-fluid interaction for the large-amplitude snap-through vibrations and higher voltage output. Controlled laboratory experiments are conducted in a water tank on the bio-inspired bi-stable piezoelectric energy harvester using a servo motor system to simulate fish swing motion at various conditions to evaluate the power generation performance. The preliminary underwater experimental results demonstrated that the proposed bio-inspired bi-stable piezoelectric energy harvester could effectively convert fish swing motions into electricity. The device collected 17.25 mJ of energy over 130 s under a peak-to-peak swing angle of 30o at 1.5 Hz in the capacitor charging experiments.

シャフトの変形挙動に変化を与えるスイング中の動作の抽出に向けた取り組み

Golf is a sport that can be enjoyed by people of all ages. The appeal of golf is not only the competition of scores, but also the feeling of satisfaction that comes from hitting an accurate shot. For accurate shots, it is necessary to use a club that is suitable for each individual swing. Just as the swing is different for each golfer, the deformation behavior of the shaft during the swinging motion is also considered to be different for each golfer. Therefore, several researches has been conducted on swing motion and shaft deformation behavior to select the appropriate club for swinging, but the swing motion that makes a difference in deformation behavior has not been clarified. Therefore, the objective of this study is to extract the golfer's swing motion that gives characteristic differences in the deformation behavior of the shaft. First, a simulation model that reproduced the deformation behavior of the shaft was constructed using FEM. The deformation behavior of the shaft was calculated using the simulation model, and differences in deformation behavior among each golfer. Next, wavelet analysis was applied to the golfer's swing motion to confirm the temporal variation of the frequency band during the swing motion. Finally, the results of the wavelet analysis were used to extract differences in the swinging motion that cause differences in the deformation behavior.

ゴルフスイングに関連する基本動作の改善がスイング動作に与える影響の調査

Golf is a sport that can be enjoyed by people of all ages. The appeal of golf is not only the competition of scores, but also the feeling of satisfaction that comes from hitting an accurate shot. For accurate shots, it is necessary not only to use clubs suitable for the golfer’s swings, but also to improve swinging motion. Many golfers wish to improve their swing, but it is difficult to do so easily because the swinging motion is complex and because each golfer swing is unique. Therefore, the purpose of this study is to propose a golf swing improvement method for beginners and intermediate golfers based on the hypothesis that beginners and intermediate golfers do not understand the coordinated movements of the body during the golf swing. First, we measured the basic movements related to the golf swing, called "exercise movements," of beginners and intermediate players. After the exercise movements were measured, the instructor provided instruction to improve the exercise movements. After the improvement of the exercise movements was confirmed, singular value decomposition was performed on the exercise movements before and after the improvement, the exercise movements were decomposed into multiple cooperative movements, and the original and improved cooperative movements were compared. Finally, we compared the swing movements before and after the exercise movements and investigated the effect of the improvement of the exercise movements on the swing movements.

An application of Chasles' theorem to describe the rotation axis of golf swing

The purpose of this study was to propose a method for describing the rotational motion of the entire golf swing by two lines about which the trunk and the lower limbs rotate respectively, and to visualize individual differences in the rotation axes. Three-dimensional whole-body motion data of three male golfers were collected using an IMU motion capture system and a helical axis was computed for each body segment at each interval of frames. The weighted average of the helical axes of the head, upper trunk, and lower trunk segments was computed for each interval to represent the rotation axis of the trunk. Similarly, the weighted average was calculated for femur, leg, and foot segments to represent the rotation axis of the lower limbs. The mean values and standard deviations of the position and orientation of each rotation axis were computed over each of the two swing phases (backswing phase & downswing phase) and animated as cones in computer graphics. Comparisons of the rotation axes among the three golfers revealed that the position and the direction of the axes are unique to each player.

Numerical Analysis of Golf Swing using Hilbert-Huang Transformation

Golf swing analysis is mainly performed using a high-speed camera and a device called a Trackman. Trackman can collect club data, ball data, putting data, etc., and the high-speed camera can record images at 6000 Hz. However, these devices are quite expensive and difficult to introduce to the general golfer. This research adopts an inexpensive inertial motion capture, Perception Neuron 2.0, to numerically capture motion and identify the differences between motions that result in straight and slice ballistics. In general, the left half of the body opening, and the head up are known to cause a slice ballistic of the golf ball. In this research, the analysis focuses on the front left half body and the head motion. The captured golf swing motion data is then processed by Hilbert-Huang Transform to calculate their instantaneous frequency and instantaneous amplitude. The result of the research found differences at the moment of impact of the golf swing at low frequencies. The amplitude of the straight ballistic motion of the head and the left shoulder increases at the moment of impact of the swing. On the other hand, the amplitude of the slice ballistic motion of the head and the left shoulder increases before impact. These results indicate that the slice ballistic motion is causes by an opening of the left half of the body and head-up from a biomechanical viewpoint.

Development of Upper Limb Simulation Model for Racket Shaft Designing in Badminton Swing Motion

The purpose of this study is to quantify the effects of various factors on player performance and to obtain useful suggestions for racket designing by constructing a three-dimensional simulation model of badminton swing motion. The racket model consists of a shaft section divided into four rigid segments, with virtual joints with rotational springs between adjacent segments, and elastic torques acting in response to angular displacement and angular velocity to represent shaft bending. For the upper limb, the hand, forearm, and upper arm were modeled as a three-segment rigid body model. The torque acting on the virtual joints of each joint and grip section is controlled by PD control, which sets the control gain according to the joint angle and angular velocity calculated based on the observed values for the input joint torque, to obtain a joint torque reduces the error between the motion generated by the simulation and the actual motion. The results obtained from the simulations, effects of shaft design factors on various evaluation quantities were calculated. Regarding the validity of the model, although the obtained model represented the racket head speed during the swing well, it was observed that the error near impact was larger than that of the actual measurement.

Transport control of a swivel crane based on a highly versatile vibration suppression trajectory

In this study, methods for automatically controlling load transportation by a swivel crane with high speed and suppressed swing motion of suspended load are proposed. First, highly versatile trajectories for each of swivel and straight transport of load are proposed on the basis of a linearized and simplified analytical model and the optimal control theory. The proposed method has the versatility that it can be applied even with different swivel radii and swivel angles. The effectiveness and limitations of the proposed methods are shown with computer simulations and experiments with a laboratory model. Next, we propose a new method that expands the proposed method and uses the measurement data of the swing information of the load. It is shown that by using this method, even if the load swings at the start of transport, it is possible to suppress the swing of the load at the target point of transport.

Characteristics of arm swing movements during sprinting in upper grade elementary school children, focusing on gender and ability differences

Characteristics of arm swing movements during sprinting in upper grade elementary school children, focusing on gender and ability differences

Verification of the Effectiveness of Arm Swing Movement in Motion Generation and Control of Forward Jump for a Humanoid Robot Based on the Relative Angular Acceleration

Verification of the Effectiveness of Arm Swing Movement in Motion Generation and Control of Forward Jump for a Humanoid Robot Based on the Relative Angular Acceleration

다기능 조파기의 조파 운동과 발생 파형

Piston type wave makers or flap type wave makers are usually adopted as a wave maker which disturbing the fluid domain with sinusoidal motion. Recently hybrid wave maker which could be operated as not only piston type and/or flap type but also swing type wave maker have been devised by utilizing the link mechanism. The wave board of hybrid wave maker has been devised to be independently controlled by the horizontal actuators on upper and lower end of the wave board. The wave board could operate as a flap type wave board when the lower hinge is in a stationary condition and the upper hinge is operated with sinusoidal motion. On the contrary, the swing type wave board could be obtained by the lower hinge is activated and the upper hinge is in a stationary condition. When both end of the wave board is activated in a synchronized condition, the wave board motion become piston motion. In addition the hybrid wave maker could enhance the piston motion with flap motion or swing motion by selecting control parameters. Various wave board motion of hybrid wave maker and relevant wave form have measured on the wave board and departed location. It is appeared that the novel hybrid wave maker could be utilized for the improvement of wave qualities in experiments.

Rub-impact dynamic analysis of a rotor with multiple wide-chord blades under the gyroscopic effect and geometric nonlinearity

In turbo-machinery, wide-chord blades are widely used due to the advantages of improving fan efficiency and aerodynamic performance. The rotor with multiple wide-chord blades is spaced from the outer casing. The small clearance may cause rub-impact fault between wide-chord blades and the casing, which induces different damage severity or the destruction of the whole machine. Numerical simulation is necessary to analyze this kind of rub-impact fault, but the solution process becomes complicated because of the coupling of geometric nonlinearity, local vibrations of wide-chord blades and gyroscopic motion of the rotor. This paper develops a rubbing rotor model with multiple wide-chord blades considering the gyroscopic effect and geometric nonlinearity induced by rub-impact. Based on the rub-impact model established for wide-chord blades, the high-order nonlinear governing equations of the bladed rotor are derived. Vibration responses are solved, and a series of dynamic characteristic analysis is carried out. The results reveal that high-order nonlinearity has a little effort on vibrations during slight rub-impact. But with the increase of transverse deformation induced by severe tip-rub, its influence cannot be ignored. Besides, localized rub-impact phenomenon of blades induced by external synchronous forces is found. Instead, external asynchronous force makes all blades rub, one after another along the circumferential direction of the disk, and there is a phase differenceΔφ=2π/Ω±ωNbbetween the vibration responses of adjacent blades. Then, we found that the swing motion intensifies the difference of transverse deformations along the chord direction of wide-chord blades with tip-rub, which may induce the edge failures. Also, the swing motion intensifies the steady rub-impact fault. It could weaken or eliminate its divergence and instability when the rotor with multiple wide-chord blades is unstable. The gyroscopic effect could weaken the swing motion, and then weakens the stable rub-impact fault.

The Role of Muscle Spindle Feedback in the Guidance of Hindlimb Movement by the Ipsilateral Forelimb during Locomotion in Mice.

Safe and efficient locomotion relies on placing the foot on a reliable surface at the end of each leg swing movement. Visual information has been shown to be important for determining the location of foot placement in humans during walking when precision is required. Yet in quadrupedal animals where the hindlimbs are outside of the visual field, such as in mice, the mechanisms by which precise foot placement is achieved remain unclear. Here we show that the placement of the hindlimb paw is determined by the position of the forelimb paw during normal locomotion and in the presence of perturbations. When a perturbation elicits a stumbling corrective reaction, we found that the forelimb paw shifts posteriorly relative to body at the end of stance, and this spatial shift is echoed in hindlimb paw placement at the end of the swing movement. Using a mutant mouse line in which muscle spindle feedback is selectively removed, we show that this posterior shift of paw placement is dependent on muscle spindle feedback in the hindlimb but not in the forelimb. These findings uncover a neuronal mechanism that is independent of vision to ensure safe locomotion during perturbation. This mechanism adds to our general knowledge of how the nervous system controls targeted limb movements and could inform the development of autonomous walking machines.