Proprioceptive wake classification by a body with a passive tail

The remarkable ability of some marine animals to identify flow structures and parameters using complex non-visual sensors, such as lateral lines of fish and the whiskers of seals, has been an area of investigation for researchers looking to apply this ability to artificial robotic swimmers, which could lead to improvements in autonomous navigation and efficiency. Several species of fish in particular have been known to school effectively, even when blind. Beyond specialized sensors like the lateral lines, it is now known that some fish use purely proprioceptive sensing, using the kinematics of their fins or tails to sense their surroundings. In this paper we show that the kinematics of a body with a passive tail encode information about the ambient flow, which can be deciphered through machine learning. We demonstrate this with experimental data of the angular velocity of a hydrofoil with a passive tail that lies in the wake generated by an upstream oscillating body. Using convolutional neural networks, we show that with the kinematic data from the downstream body with a tail, the wakes can be better classified than in the case of a body without a tail. This superior sensing ability exists for a body with a tail, even if only the kinematics of the main body are used as input for the machine learning. This shows that beyond generating 'additional inputs', passive tails modulate the response of the main body in manner that is useful for hydrodynamic sensing. These findings have clear application for improving the sensing abilities of bioinspired swimming robots.

Proprioceptive Cervicogenic Dizziness Care Trajectories in Patient Subpopulations: A Scoping Review

Proprioceptive cervicogenic dizziness (PCGD) is the most prevalent subcategory of cervicogenic dizziness. There is considerable confusion regarding this clinical syndrome's differential diagnosis, evaluation, and treatment strategy. Our objectives were to conduct a systematic search to map out characteristics of the literature and of potential subpopulations of PCGD, and to classify accordingly the knowledge contained in the literature regarding interventions, outcomes and diagnosis. A Joanna Briggs Institute methodology-informed scoping review of the French, English, Spanish, Portuguese and Italian literature from January 2000 to June 2021 was undertaken on PsycInfo, Medline (Ovid), Embase (Ovid), All EBM Reviews (Ovid), CINAHL (Ebsco), Web of Science and Scopus databases. All pertinent randomized control trials, case studies, literature reviews, meta-analyses, and observational studies were retrieved. Evidence-charting methods were executed by two independent researchers at each stage of the scoping review. The search yielded 156 articles. Based on the potential etiology of the clinical syndrome, the analysis identified four main subpopulations of PCGD: chronic cervicalgia, traumatic, degenerative cervical disease, and occupational. The three most commonly occurring differential diagnosis categories are central causes, benign paroxysmal positional vertigo and otologic pathologies. The four most cited measures of change were the dizziness handicap inventory, visual analog scale for neck pain, cervical range of motion, and posturography. Across subpopulations, exercise therapy and manual therapy are the most commonly encountered interventions in the literature. PCGD patients have heterogeneous etiologies which can impact their care trajectory. Adapted care trajectories should be used for the different subpopulations by optimizing differential diagnosis, treatment, and evaluation of outcomes.

Sensory Involvement in Amyotrophic Lateral Sclerosis

Although amyotrophic lateral sclerosis (ALS) is pre-eminently a motor disease, the existence of non-motor manifestations, including sensory involvement, has been described in the last few years. Although from a clinical perspective, sensory symptoms are overshadowed by their motor manifestations, this does not mean that their pathological significance is not relevant. In this review, we have made an extensive description of the involvement of sensory and autonomic systems described to date in ALS, from clinical, neurophysiological, neuroimaging, neuropathological, functional, and molecular perspectives.

A Prospective Study on Autotransplantation of Mandibular Third Molars With Complete Root Formation

Study Design

Autotransplantation, if possible, is a viable option for replacing a missing tooth when a donor tooth is available. The most typical tooth transplant is the transfer of a third molar to a first molar site. No immune reaction results from transplants of this nature. It restores the proprioceptive function and normal periodontal healing; thus, the patient can have a natural chewing feeling and natural biological response.

Objective

This study aims to evaluate the prognosis of autotransplanted mandibular third molar and also to evaluate the cost effectiveness of the treatment performed when compared to the other treatment modalities for prosthetic rehabilitation.

Methods

A prospective study was done in the Department of Oral & Maxillofacial Surgery, Sardar Patel Post Graduate Institute of Dental & Medical Sciences, Lucknow, UP, India, with over 20 patients to evaluate the prognosis of autotransplanted mandibular third molars with complete root formation after atraumatic extraction of first or second mandibular molar, which were randomly selected irrespective of race, sex, caste, and socio-economic status. Regular clinical and radiographical examinations were performed over a period of 1 year and the patients were assessed for pain, swelling, infection, dry socket, periodontal pocket depth, ankylosis, root resorption, tooth mobility, and level of buccal bone in relation to cementoenamel junction (CEJ).

Results

Eighteen out of 20 transplants were successful; only 2 mandibular transplants were extracted because of abnormal horizontal and axial mobility and the reason of failure was attributed to fact that the roots of transplant were short and conical and there was lack of alveolar bone height at the recipient site in one patient, while root resorption was the reason for failure of transplant in the other patient.

Conclusions

This study assessed the efficacy of autotransplantation of molars and the viability of the procedure to replace unrestorable molar teeth; it also supports the hypothesis that transplantation of a mandibular third molar for replacement of a lost or seriously damaged molar tooth could be a reasonable alternative.

Effects of ankle joint proprioceptive training and thermal approach on stroke patients' trunk, balance stability and gait parameter

BACKGROUND

Numerous studies have investigated factors for trunk, balance stability and gait parameters of post-stroke patients. Evidence-based recommendations are required for the treatment of ankle proprioceptive exercise with thermal stimulation in post-stroke patients.

OBJECTIVE

We investigated the effects of ankle proprioceptive exercise with thermal stimulation on the trunk stability, balance, and gait ability of post-stroke patients.

METHODS

A total of 30 patients were randomly divided into the ankle proprioceptive training and thermal stimulation group (APT) and control group. The APT group performed ankle proprioceptive exercises with thermal stimulation for 60 min five times a week for eight weeks. The control group followed conservative treatment for 60 min five times a week for eight weeks. Trunk stability was measured with the trunk impairment scale (TIS) and balance tests were performed with the center of pressure (COP), limits of stability (LOS), Berg Balance Scale (BBS), and functional reach test (FRT) and gait ability was performed by OptoGait and 10 m WT.

RESULTS

There was a significant difference (p< 0.05) between before and after training in both groups. The APT group showed significant improvement in both groups.

CONCLUSION

This study can be used as intervention data for recovering trunk, balance stability and gait parameters in post-stroke patients.

Proprioceptive contribution to oculomotor control in humans

Stretch receptors in the extraocular muscles (EOMs) inform the central nervous system about the rotation of one's own eyes in the orbits. Whereas fine control of the skeletal muscles hinges critically on proprioceptive feedback, the role of proprioception in oculomotor control remains unclear. Human behavioural studies provide evidence for EOM proprioception in oculomotor control, however, behavioural and electrophysiological studies in the macaque do not. Unlike macaques, humans possess numerous muscle spindles in their EOMs. To find out whether the human oculomotor nuclei respond to proprioceptive feedback we used functional magnetic resonance imaging (fMRI). With their eyes closed, participants placed their right index finger on the eyelid at the outer corner of the right eye. When prompted by a sound, they pushed the eyeball gently and briefly towards the nose. Control conditions separated out motor and tactile task components. The stretch of the right lateral rectus muscle was associated with activation of the left oculomotor nucleus and subthreshold activation of the left abducens nucleus. Because these nuclei control the horizontal movements of the left eye, we hypothesized that proprioceptive stimulation of the right EOM triggered left eye movement. To test this, we followed up with an eye-tracking experiment in complete darkness using the same behavioural task as in the fMRI study. The left eye moved actively in the direction of the passive displacement of the right eye, albeit with a smaller amplitude. Eye tracking corroborated neuroimaging findings to suggest a proprioceptive contribution to ocular alignment.

Body Balance of Children and Youths with Visual Impairment (Pilot Study)

AIM

The study was designed to assess the effects of surface instability in the response of the balance control system in children and youths with visual impairment (BL) and in normally sighted controls (NE).

MATERIALS AND METHODS

The empirical research study involved 80 individuals, aged from 6 to 20 years, with a mean age of 14.37 (±4.68), including 40 blind individuals and a randomly selected control group 40 normally sighted. Stabilometric measurements were performed with the use of the Platform CQ Stab 2P, with eyes open (EO) and closed (EC) on the solid surface, and then, the same procedure was performed on the platform covered with 1-centimetre-thick foam.

RESULTS

Statistical analyses (Wilcoxon matched-pairs test, Mann-Whitney U test) of the results identified during the trials reveal the following findings in the BL group in the EO and EC tests. The results of the foam surface test were higher and the differences were statistically significant in the BL group (sway path EO p = 0.009, EC p = 0.006; mean amplitude EC p = 0.030; mean velocity EO p = 0.009, EC p = 0.006; sway area EO p = 0.017, EC p = 0.009; and number of COP deflections along the sagittal plane EO p = 0.004). No similar correlations were observed in the NE group, except for the mean amplitude EO p = 0.033 and sway area EO p = 0.030. There was one difference between the BL and the NE group for the mean amplitude parameter, p = 0.018, in a solid surface test with open eyes. The results were higher in the BL group.

CONCLUSIONS

The present study showed no worse balance in the BL group than in the NE group but worse performance on the foam than without it. It indicates the need to develop body balance skills in blind people by improving their proprioceptive sensitivity. In everyday life and training, blind people should experience exteroceptive stimuli, different textures, and unstable surfaces as much as possible.

Postural Sway in Older Patients with Sagittal Imbalance and Young Adults during Local Vibratory Proprioceptive Stimulation

This study aimed to assess differences in somatosensory control strategies between older patients with sagittal imbalance and young adults during postural tasks. The center of pressure displacement in 27 older patients with sagittal imbalance and 27 young adults was determined upon standing blindfolded on a balance board. Vibratory stimulation at 56 to 100 Hz was applied bilaterally to the gastrocnemius and soleus muscles (GS) and lumbar multifidus to evaluate the contributions of proprioceptive signals to postural control. Data of older patients and young adults were compared using the Mann–Whitney U-test or independent sample t-tests. Compared with the young adults, the older patients were significantly more reliant on the GS (p < 0.005) for their postural control and showed a higher relative proprioceptive weighting ratio (RPW) (p = 0.038). The postural strategy adopted by the older patients depended on the level of proprioceptive stimulation applied to the GS, and the postural control strategy of the ankle correlated with RPW. Overall, this study identifies RPW as a novel measure of postural strategy in older patients with sagittal imbalance and provides an understanding of strategies used to maintain balance, which may assist in developing preventative measures to reduce the risk of falls.

Clinical Characteristics and Clinical Course of Body Lateropulsion in 47 Patients with Brainstem Infarctions

BACKGROUND

In patients with lower lateral medullary infarction (LMI) located under the vestibular nucleus, proprioceptive impairment due to dorsal spinocerebellar tract (DSCT) is considered a pathological condition for body lateropulsion. In patients with brainstem infarction located at or above the level of the vestibular nucleus, other pathways, such as the crossed vestibulothalamic tract (CVTT), are considered responsible.

RESEARCH QUESTION

The clinical course of body lateropulsion between each anatomical level of infarction remains unclear. Further, whether body lateropulsion refers to a static or a dynamic symptom also remains unclear.

METHODS

We examined 47 patients who exhibited body lateropulsion and categorized them into four groups: lower LMI under the vestibular nucleus, LMI at the level of the vestibular nucleus, pontine infarction, and midbrain infarction. The patients' time to acquire static upright standing position and gait in a straight line were statistically analyzed by a log-rank test using the Kaplan-Meier method.

RESULTS

Body lateropulsion in the static upright position was less frequent in the lower LMI group than in the other groups.

SIGNIFICANCE

Lower LMI primarily affected body lateropulsion in gait. DSCT damage could affect ipsilateral hip joint or leg coordination, causing body lateropulsion in dynamic situation.

Effects of an 8-week basketball-specific proprioceptive training with a single-plane instability balance platform

BACKGROUND

To avoid injuries in basketball players, they are recommended to pay more attention to improve their body balance. Therefore new training methods and equipment need to be devised. This study examined the effects of an 8-week basketball-specific proprioception training program while using a new developed one plane instability balance board during warm-up for improving balance ability in basketball players. Players who obtained basketball-specific balance training were compared to a control group.

METHODS

Thirty-one male university basketball players (age: 21.35, SD = 0.605 years; height: 190.97, SD = 1.88; body mass: 86.95, SD = 2.61) participated in this study. Seventeen participants were assigned to the basketball-specific 8-week balance training group (BTG) while 14 participants served as a control group (CG). Both groups were tested with the Y balance test (YBT) and postural stability test (PST) at baseline and 8 weeks later.

RESULTS

The results indicate significant improvements in the overall YBT for both legs in BTG, but not in CG. However, no group differences were found for dynamic balance performance, but static balance (i.e., postural stability) differed between groups after 8 weeks. A statistically significant moderate inverse correlation was computed between the total score of YBT and the total score of the overall stability index (r=-0.404; p= 0.041).

CONCLUSIONS

An 8-week basketball-specific proprioception training program with a single-plane instability balance platform improved balance ability (Y balance test and postural stability test) of basketball players.

Can Proprioceptive Training Reduce Muscle Fatigue in Patients With Motor Neuron Diseases? A New Direction of Treatment

Muscle fatigue is a serious problem in patients with motor neuron diseases (MNDs). It commonly disturbs both daily life activity and rehabilitation tolerance. A particular concern should be taken when MNDs occur in older ages. Older patients with MNDs usually have a worse clinical presentation and a lower survival rate. This could increase the occurrence of muscle fatigue. Muscle fatigue occurs due to a dysfunction in either motor or sensory systems. Current exercise interventions performed to decrease the occurrence of muscle fatigue focused only on treating motor causes of muscle fatigue. It has been demonstrated that these interventions have a high debate in their effectiveness on decreasing the occurrence of muscle fatigue. Also, these exercise interventions ignored training the affected sensory part of muscle fatigue, however, the important role of the sensory system in driving the motor system. Thus, this review aimed to develop a novel exercise intervention by using proprioceptive training as an intervention to decrease the occurrence of muscle fatigue in patients with MNDs particularly, older ones. The physiological effects of proprioceptive training to decrease the occurrence of muscle fatigue could include two effects. The first effect includes the ability of the proprioceptive training to increase the sensitivity of muscle spindles as an attempt to normalize the firing rate of α-motoneurons, which their abnormalities have major roles in the occurrence of muscle fatigue. The second effect includes its ability to correct the abnormal movement-compensations, which develop due to the biomechanical constraints imposed on patients with MNDs.

Fabrication and Dynamic Modeling of Bidirectional Bending Soft Actuator Integrated with Optical Waveguide Curvature Sensor

Soft robots exhibit many exciting properties due to their softness and body compliance. However, to interact with the environment safely and to perform a task effectively, a soft robot faces a series of challenges such as dexterous motion, proprioceptive sensing, and robust control of its deformable bodies. To address these issues, this article presents a method for fabrication and dynamic modeling of a novel bidirectional bending soft pneumatic actuator that embeds a curvature proprioceptive sensor. The bidirectional bending deformation was generated by two similar chambers with a sinusoidal shape for reducing the internal dampness during bending deformation. An optical waveguide made from flexible poly (methyl methacrylate) material that is immune to the inlet pressure was embedded into the actuator body to measure its bending angle. A dynamic modeling framework based on step response and parameter fitting was proposed to establish a simple differential equation that can describe the nonlinear behavior of the soft actuator. Hence, a sliding mode controller is designed based on this differential equation and the Taylor expansion. The proposed dynamical model and the sliding mode controller were validated by trajectory tracking experiments. The performance of the bidirectional bending soft actuator, such as the linear output of the curvature sensor in different inflating patterns, the proprioceptive sensitiveness to the external environment, the output force, and large bending range under relatively small pressure, was evaluated by relevant experimental paradigms. Prototypes from the novel design and fabrication process demonstrated the soft actuator's potential applications in industrial grasping and hand rehabilitation.

Comparative joint position error in patients with non-specific neck disorders and asymptomatic age-matched individuals

Background

Neck pain is a common complaint worldwide and ranked seventh in 2010 as the cause of ‘years lived with disability’ in Ghana. Proprioceptive dysfunction, measured by joint position error (JPE) tests, indicates an association with neck pain frequency, dizziness and balance problems in patients.

Objectives

To examine proprioceptive deficits of the neck using a laser pointer attached to the head.

Methods

Twenty patients within the age group 21–60 years, with at least five points on the neck disability index (NDI), and 20 age- and sex-matched controls with less than five points on the NDI were recruited for this study. The JPE was determined wearing a headlight laser pointer directed towards a Cartesian coordinate system adjusted to x/y = 0/0, placed on a wall after returning from left and right rotation, flexion and extension. From starting in an upright sitting position, facing the Cartesian coordinate system, each participant performed five repetitions for each movement direction. The mean of five repetitions for each movement direction was calculated as absolute error (AE), constant error (CE) and variable error (VE).

Results

Control participants showed larger JPE values for nearly all AE, CE and VE. After repositioning from flexion controls showed an approximately 0.6 ° larger median JPE, and the opposite for extension, with median differences between 1 ° and 2 °.

Conclusion

The results of this study do not reveal any meaningful differences between patients with mild disabled neck movement compared with controls.

Clinical implications

Joint position error testing does not seem useful for patients with mild neck disability.

Neural Coding of Leg Proprioception in Drosophila

Animals rely on an internal sense of body position and movement to effectively control motor behavior. This sense of proprioception is mediated by diverse populations of mechanosensory neurons distributed throughout the body. Here, we investigate neural coding of leg proprioception in Drosophila, using in vivo two-photon calcium imaging of proprioceptive sensory neurons during controlled movements of the fly tibia. We found that the axons of leg proprioceptors are organized into distinct functional projections that contain topographic representations of specific kinematic features. Using subclass-specific genetic driver lines, we show that one group of axons encodes tibia position (flexion/extension), another encodes movement direction, and a third encodes bidirectional movement and vibration frequency. Overall, our findings reveal how proprioceptive stimuli from a single leg joint are encoded by a diverse population of sensory neurons, and provide a framework for understanding how proprioceptive feedback signals are used by motor circuits to coordinate the body.

Toward Modular Soft Robotics: Proprioceptive Curvature Sensing and Sliding-Mode Control of Soft Bidirectional Bending Modules

Real-world environments are complex, unstructured, and often fragile. Soft robotics offers a solution for robots to safely interact with the environment and human coworkers, but suffers from a host of challenges in sensing and control of continuously deformable bodies. To overcome these challenges, this article considers a modular soft robotic architecture that offers proprioceptive sensing of pressure-operated bending actuation modules. We present integrated custom magnetic curvature sensors embedded in the neutral axis of bidirectional bending actuators. We describe our recent advances in the design and fabrication of these modules to improve the reliability of proprioceptive curvature feedback over our prior work. In particular, we study the effect of dimensional parameters on improving the linearity of curvature measurements. In addition, we present a sliding-mode controller formulation that drives the binary solenoid valve states directly, giving the control system the ability to hold the actuator steady without continuous pressurization and depressurization. In comparison to other methods, this control approach does not rely on pulse width modulation and hence offers superior dynamic performance (i.e., faster response rates). Our experimental results indicate that the proposed soft robotic modules offer a large range of bending angles with monotonic and more linear embedded curvature measurements, and that the direct sliding-mode control system exhibits improved bandwidth and a notable reduction in binary valve actuation operations compared to our earlier iterative sliding-mode controller.

Possible Role of the Myelinated Neural Network in the Parietal Peritoneum in Rats as a Mechanoreceptor

A network of myelinated nerve fibers in the peritoneum covers the abdominal wall. We studied the topographic distribution of this network, explored the fibers' destination in the central nervous system, and examined the markers in these fibers in order to identify the nature of the sensation conveyed by the network of nerve fibers in rats. We used Sihler's method, which stains myelinated fibers in whole mount materials, and observed a dense nerve network and endings toward the peritoneal cavity in the peritoneum that covers the abdomen's lateral bulge. We studied the axonal transport of cholera toxin subunit B to investigate the central projections of this network in order to identify its function. After applying the tracer in the peritoneum, we observed many labeled terminals in the medial part of laminae 3-5 of the spinal cord. A small number of labeled terminals was observed in the dorsal nucleus of Clarke and gracile nucleus. Labeled somata were observed in the dorsal root ganglia (DRG). Most (96%) were larger than 35 μm. We performed immunohistochemistry of the abdominal wall, using antiserum against the 200-kD neurofilament (a marker for mechanosensory neurons). We observed many positive nerve fibers in the peritoneum. Because cell bodies in the DRG were large, their nerve terminals ended in the base of the dorsal horn, which is known to transmit proprioceptive information, and the network possesses the marker for mechanosensitive fibers; therefore, it appears that the myelinated nerve network conveys information about distension and/or contraction of the abdominal wall. Anat Rec, 300:1662-1669, 2017. © 2017 Wiley Periodicals, Inc.

Novel balance rehabilitation and training apparatus to improve functional balance

A new balance rehabilitation and training apparatus has been developed to allow a balance-impaired person to cope with his or her fear of falling while safely and independently performing exercises necessary to improve functional balance. The apparatus consists of a stable platform where the user stands and a vertical structure that supports free-floating handles that the user holds with both hands while performing various exercises. The purpose of study 1 was to determine whether this new apparatus significantly alters the biological postural control system, and the purpose of study 2 was to document the benefits of balance training using the apparatus. Study 1 was a randomized repeated-measures design with six healthy adult subjects (mean age = 35.5 yr), and study 2 was a 4 wk intervention case study with a generally healthy 63-yr-old individual. The results suggest that postural sway characteristics and the cortical and proprioceptive feedback were not limited when using the apparatus. We also observed improvements in balance control and postural stability with 4 wk of training with the apparatus. These results support that the apparatus could be an effective tool to help individuals safely and independently perform balance exercises while potentially preventing falls and minimizing fear of falling.

a high-density EEG study

Multisensory integration and interaction occur when bimodal stimuli are presented as either spatially congruent or incongruent, but temporally coincident. We investigated whether proprioceptive cues interact with auditory attention to one of two sound sources in free-field. The participant's task was to attend to either the left or right speaker and to respond to occasional increased-bandwidth targets via a footswitch. We recorded high-density EEG in three experimental conditions: the participants either held the speakers in their hands (Hold), reached out close to them (Reach), or had their hands in their lap (Lap). In the last two conditions, the auditory event-related potentials (ERPs) revealed a prominent negativity around 200 ms post-stimulus (N2 wave) over fronto-central areas, which is a reliable index of further processing of spatial stimulus features in free-field. The N2 wave was markedly attenuated in the 'Hold' condition, which suggests that proprioceptive cues apparently solidify spatial information computed by the auditory system, in so doing alleviating the need for further processing of spatial coordinates solely based on auditory information.