Temporal saliency for motion direction may arise from visual stimulus-specific adaptation in avian midbrain inhibitory nucleus

Food and predators are the most noteworthy objects for the basic survival of wild animals. In nature, both of these are often rare or deviant in both spatial and temporal domains and would soon attract an animal's attention. Although stimulus-specific adaptation (SSA) is considered to be one neural basis of salient sound detection in the temporal domain, related research on visual SSA is lacking. The avian nucleus isthmi pars magnocellularis (Imc), which plays an extremely important role in the selective attention network, is one of the best models for investigating the neural correlate of visual stimulus-specific adaptation (SSA) and detection of salient stimulus in the temporal domain. Here, we used a constant order paradigm to test the existence of SSA in the pigeon's Imc. We found that the strength of response of Imc neurons significantly decreased after repetitive motion stimuli, but recovered when the motion was switched to a novel direction, leading to the saliency detection of the novel motion direction. These results suggest that the inhibitory nucleus Imc shows visual SSA to motion direction, allowing the Imc to implement temporal saliency mapping and to determine the spatial-temporal saliency of the current stimulus. This also implies that pigeons may detect novel spatial-temporal stimuli during the early stage of sensory processing.

Manual Therapy With Rest as a Treatment for Established Inflammation and Fibrosis in a Rat Model of Repetitive Strain Injury

Background: Repetitive strain injuries caused by repetitive occupational work are difficult to prevent for multiple reasons. Therefore, we examined the effectiveness of manual therapy (MT) with rest to treat the inflammation and fibrosis that develops through the performance of a repetitive task. We hypothesized that this treatment would reduce task-induced sensorimotor declines and neuromuscular inflammation.Methods: Twenty-nine female Sprague-Dawley rats performed a reaching and lever-pulling task for 14weeks. All ceased performing the task at 14weeks. Ten were euthanized at this timepoint (TASK). Nine received manual therapy to their upper extremities while resting 7weeks (MTR); 10 were assigned to rest alone (REST). Ten additional food restricted rats were included that neither performed the task nor received manual therapy (FRC).Results: Confirming previous experiments, TASK rats showed behavioral changes (forepaw mechanical hypersensitivity, reduced grip strength, lowered forelimb/forepaw agility, and noxious cold temperature sensitivity), reduced median nerve conduction velocity (NCV), and pathological tissue changes (myelin degradation, increased median nerve and muscle inflammation, and collagen production). Manual therapy with rest (MTR) ameliorated cold sensitivity seen in REST rats, enhanced muscle interleukin 10 (IL-10) more than in REST rats, lead to improvement in most other measures, compared to TASK rats. REST rats showed improved grip strength, lowered nerve inflammation and degraded myelin, and lowered muscle tumor necrosis factor alpha (TNFα) and collagen I levels, compared to TASK rats, yet maintained lowered forelimb/forepaw agility and NCV, and increased neural fibrosis.Conclusion: In our model of repetitive motion disorder, manual therapy during rest had modest effects on behavioral, histological, and physiological measures, compared to rest alone. These findings stand in contrast to the robust preventive effects of manual therapy in this same model.

Corrugated Diaphragm Actuator for Soft Robotic Applications

Soft robotics is projected to have a significant impact on healthcare, industry, and the military to deliver assistance in rehabilitation, daily living activities, repetitive motion tasks, and human performance augmentation. Many attempts have been made for application-specific robotic joints, robots, and exoskeletons using various actuator types, materials, and designs. The progress of creating soft robotic systems can be accelerated if a set of actuators with defined characteristics were developed, similar to conventional robotic actuators, which can be assembled to create desired systems including exoskeletons and end effectors. This work presents the design methodology of such a modular actuator, created with a novel corrugated diaphragm that can apply linear displacement, angular displacement, and force. This modular actuator approach allows for creating various robotic joints by arranging them into different configurations. The modular corrugated diaphragm actuator concept was validated through numerical simulation, fabrication, and testing. Linear displacement, angular displacement, and force characteristics were shown for a single module and in multi-module assemblies. Actuator assemblies that are configured in a serial and parallel manner were investigated to demonstrate the applicability and versatility of the concept of the modular corrugated diaphragm actuator for creating single and multi-DOF joints.

New repetitive motion planning scheme with cube end-effector planning precision for redundant robotic manipulators

Repetitive motion planning (RMP) is important in operating redundant robotic manipulators. In this paper, a new RMP scheme that is based on the pseudoinverse formulation is proposed for redundant robotic manipulators. Such a scheme is derived from the discretization of an existing RMP scheme by utilizing the difference formula. Then, theoretical analysis and results are presented to show the characteristic of the proposed RMP scheme. That is, this scheme possesses the characteristic of cube pattern in the end-effector planning precision. The proposed RMP scheme is further extended and studied for redundant robotic manipulators under joint constraint. Based on a four-link robotic manipulator, simulation results substantiate the effectiveness and superiority of the proposed RMP scheme and its extended one.

Corrugated Diaphragm Actuator for Soft Robotic and Exoskeleton Applications

Soft robotics is projected to have a significant impact on healthcare, industry, and the military to deliver assistance in rehabilitation, daily living activities, repetitive motion tasks, and human performance augmentation. Many attempts have been made for application-specific robotic joints, robots, and exoskeletons using various actuator types, materials, and designs. The progress of creating soft robotic systems can be accelerated if a set of actuators with defined characteristics were developed, similar to conventional robotic actuators, which can be assembled to create desired systems including exoskeletons and end effectors. This work presents such an attempt by designing a modular corrugated diaphragm actuator that can apply linear displacement, force, and bending motion. This modular actuator approach allows for creating various robotic joints by arranging them into different configurations. Numerical simulation, fabrication, and testing were carried out to evaluate the displacement, force, and bending characteristics of the corrugated diaphragm actuator as a single unit and in multi-unit arrays to understand their applicability for different scenarios. Actuator arrays that are configured in a serial and parallel manner were investigated. The results will be presented in terms of using this modular actuator concept to create single and multi-DOF joints, which will demonstrate the versatility of this modular actuator approach.

Worker Injuries in Southern California’s Warehousing Industry: How to Better Protect Workers in This Burgeoning Industry?

Dangerous conditions and worker injuries in the rapidly growing warehousing industry have gained attention in recent years, with accounts typically drawing on worker reports and investigative journalism. We analyzed workers’ compensation injury claims and California Division of Occupational Safety and Health (Cal/OSHA) citations in Southern California’s large warehousing sector. Claims increased from 2014 to 2018, with a majority of injuries caused by repetitive motion, lifting and other ergonomic risk factors. Cal/OSHA cited employers for violating standards to protect workers from unsafe vehicle operations, dangerous machinery and equipment, and falls; and for failing to implement injury prevention programs. These citations address the causes of some worker injuries; however, no Cal/OSHA citations were issued for violating the state’s Repetitive Motion Injuries prevention standard. Nor do enforcement activities address the underlying causes highlighted by workers—high production quotas and a relentless work pace—that characterize the industry. We discuss the value and limitations of our approach and the implications of our results.

Evaluation of the relationship between history of lower back pain and asymmetrical trunk range of motion

BACKGROUND: Low back pain (LBP) is a common complaint and preventive measures should be considered immediately. In addition, asymmetrical trunk motion, which occurs due to repetitive motion upon performing daily activities, may be one of the biomechanical factors to cause LBP. OBJECTIVE: To investigate the characteristics of asymmetrical trunk motion in women with a history of LBP. METHODS: Thirty-four women were dichotomously categorized into either the LBP or non-LBP group. Trunk active range of motion (RoM) upon sitting and standing were measured via a three-dimensional motion analysis system. Each RoM and rotation and side-flexion asymmetries were calculated and an unpaired t-tests were used to identify differences between each group. RESULTS: Trunk rotation asymmetry upon sitting and standing position in LBP group was significantly greater than that in non-LBP group. Furthermore, trunk rotation angle upon sitting in LBP group was significantly larger than that in non-LBP group. CONCLUSIONS: The limited RoM and asymmetry of trunk rotation may be due to imposed repetitive mechanical stress on habitual excessive motion, including most asymmetrical movements. Our findings indicated that a small trunk rotation angle and asymmetrical trunk rotation may be useful parameters to predict LBP onset or other musculoskeletal conditions of the trunk.

FAKTOR RISIKO CARPAL TUNNEL SYNDROME PADA SISWA SEKOLAH MENENGAH ATAS PEMAIN GAME ONLINE DI KOTA DENPASAR

ABSTRAK Carpal Tunnel Syndrome (CTS) merupakan salah satu gangguan pada lengan tangan akibat penyempitan terowongan karpal sehingga terjadi penekanan terhadap nervus medianus. Gerakan tangan saat menggunakan keyboard dan mouse dalam bermain game online memiliki tingkat repetisi tinggi pada jari tangan sehingga dapat berpengaruh terhadap kejadian CTS. Penelitian ini bertujuan untuk mengetahui proporsi dan faktor risiko CTS pada siswa SMA pemain game online di Kota Denpasar. Penelitian kuantitatif analitik dengan rancangan cross-sectional study. Responden berjumlah 70 siswa dengan teknik pengambilan sampel purposive sampling. Hasil menunjukan proporsi CTS responden sebesar 31,43% dengan kategori ringan. Seluruh variabel karakteristik individu yang mencakup usia (p=0,25) dan jenis kelamin (p=0,50) tidak memiliki hubungan yang bermakna dengan kejadian CTS, sedangkan variabel pola bermain, perangkat bermain, dan repetitive motion (p=0,00) terbukti memiliki hubungan bermakna dengan kejadian CTS. Pola bermain merupakan faktor risiko yang paling berpengaruh terhadap kejadian CTS pada siswa pemain game online dengan OR= 23,74. Oleh karena itu diperlukan adanya dukungan pemerintah berupa program preventif - rehabilitatif bagi pecandu game untuk mengedukasi siswa dan orangtua terkait dampak game online. Kata Kunci: Carpal Tunnel Syndrome, Siswa, Game Online

Line scan-based rapid magnetic resonance imaging of repetitive motion

Two-dimensional (2D) line scan-based dynamic magnetic resonance imaging (MRI) is examined as a means to capture the interior of objects under repetitive motion with high spatiotemporal resolutions. The method was demonstrated in a 9.4-T animal MRI scanner where line-by-line segmented k-space acquisition enabled recording movements of an agarose phantom and quail eggs in different conditions—raw and cooked. A custom MR-compatible actuator which utilized the Lorentz force on its wire loops in the scanner’s main magnetic field effectively induced the required periodic movements of the objects inside the magnet. The line-by-line k-space segmentation was achieved by acquiring a single k-space line for every frame in a motion period before acquisition of another line with a different phase-encode gradient in the succeeding motion period. The reconstructed time-course images accurately represented the objects’ displacements with temporal resolutions up to 5.5 ms. The proposed method can drastically increase the temporal resolution of MRI for imaging rapid periodic motion of objects while preserving adequate spatial resolution for internal details when their movements are driven by a reliable motion-inducing mechanism.