Passive Movement Research Articles

Passive Movement Exercise of the Lower Limbs May Facilitate Wound Healing in Patients With Diabetic Foot Ulcers

Passive Movement Exercise of the Lower Limbs May Facilitate Wound Healing in Patients With Diabetic Foot Ulcers

Neonatal Proximal Humerus Osteomyelitis: A Case Report and Literature Review

Objective − This case report was written with the purpose of educating neonatal caregivers with regard to the early detection of osteomyelitis in order to start treatment quickly and avoid the devastating consequences later with lifelong disability.Case Report − We present a 20-day-old newborn with a lack of spontaneous movement of the right arm, which first occurred 5 days prior. The newborn was diagnosed with Erb’s palsy, and physiotherapy was started. Upon re-examination, he did not move his right arm, his shoulder was slightly swollen, he was afebrile, and C-reactive protein was elevated. The initial radiographic finding was normal, but the ultrasound evaluation found evidence of proximal humerus osteomyelitis. Over the next two days, the condition did not improve despite the included therapy (vancomycin and amikacin). Then, joint drainage surgery was performed. The radiographic finding upon discharge showed significant destruction of the proximal humerus and shoulder joint. At the age of 12 months, the range of motion in the affected shoulder joint was less than in the left.Conclusion − Regular arm mobility in the early postpartum days, pseudoparalysis on examination, a swollen and raised shoulder, pain during passive movements, a positive ultrasound examination, and a high level of C-reactive protein are data that can reliably indicate the onset of osteomyelitis of the proximal humerus and help in the differential diagnosis between osteomyelitis and Erb’s palsy. The lack of timely diagnosis of osteomyelitis and the delayed inclusion of therapy can lead to late consequences, such as significant destruction of the proximal humerus and the shoulder joint.

Early pain findings in infants with brachial plexus birth injury: Relationship with function and comorbidities, and cut-off point for fractures

BackgroundInfants with birth brachial plexus injury (BPBI) may have various comorbidities such as fractures, torticollis, plagiocephaly, central nervous system disorders. In infants with BPBI, it is important to identify fractures, which are common among comorbidities, objectively assess pain, and investigate factors that may be associated with pain. AimThe aim of this study is to determine the pain level, comorbidities, and motor function in infants with BPBI and to examine the relationship between these parameters. The second aim is to determine the cut-off value of the pain score that may be a sign of fracture in patients with BPBI, in order to suspect and predict a fracture in the shoulder region and to request additional examinations. Subjects and measurements59 infants with BPBI aged 15–90 days were included in the study. Comorbidities, active joint movements, and total upper extremity function assessed with the Active Movement Scale and pain scores measured with the FLACC Pain Scale were retrospectively analyzed. In addition, pain, comorbidities and motor function were investigated according to types of Narakas, which indicates the degree of nerve injury. ResultsOf the 59 participants, 18 (30.5 %) had at least one comorbidity and 12 (20.3 %) had fractures. The number of comorbidities (p = 0.41), the number of fractures (p = 0.84), and the level of pain (p = 0.71) did not differ by types of Narakas. There was a moderate negative correlation between pain level and upper extremity motor function in upper trunk injuries (p < 0.5, −0.67 < r < −0.46). There was a difference in pain level measured by palpation (p < 0.01) and passive joint movement (p < 0.01) in infants with and without comorbidities. To suspect a fracture in the shoulder region and to request further evaluation, the cut-off value of the Flacc pain level, which may predict a fracture, was 3.5 points for palpation and passive shoulder abduction and 4.5 points for passive external rotation. ConclusionThis is the first study in the BPBI to measure pain in infants using a quantifiable and widely used assessment. Pain level was ranked from high to low as infants with fractures, infants with comorbidities other than fractures and infants without comorbidities. Increased pain adversely affects motor function and pain above the cut-off values is a predictor of fracture.

The Pericoracoid Tissue Release in Children With Brachial Plexus Birth Injury

In brachial plexus birth injury (BPBI), children with upper trunk injuries have multidirectional movement deficits, including global abduction and hand-to-neck, hand-to-abdomen, and hand-to-spine movements. The aim of this study was to evaluate the results of pericoracoid tissue release and postoperative structured physiotherapy as a first-step intervention to reduce the multidirectional movement deficit in children with BPBI. Thirty-four children with BPBI underwent pericoracoid tissue release, including coracohumeral and coracoacromial ligament release, pectoralis minor release, and coracoid process osteotomy. Patients were followed up with regular physiotherapy and a home exercise program for 1 year after surgery. Before surgery and at 3 and 12 months after surgery, upper-extremity function was measured using the modified Mallet classification and Active Movement Scale, passive shoulder and elbow joint movements were measured using goniometry, and the difference in the distance between the treatment table and the acromion was measured. There was an improvement in all movement tasks evaluated with modified Mallet classification, and there was increased shoulder flexion, abduction, and external and internal rotation movements as evaluated with Active Movement Scale. Increased passive joint movements were noted in abduction, external rotation, and internal rotation movements with the arm next to the body and with the limb in 90° abduction. There was a decrease in the distance difference between the acromion and the treatment table between both sides. Pericoracoid tissue release provided multidirectional improvement in shoulder joint movements in children with BPBI. Therapeutic IV.

The presence of an avatar can reduce cybersickness in Virtual Reality

Virtual Reality (VR) applications are increasingly being utilized for research, healthcare, and education. Despite their benefits, many VR users report motion sickness-like sensations (cybersickness), such as headache, disorientation, or nausea. Previous studies suggest that the sense of presence (“being there”) in the virtual world may contribute to the severity of cybersickness; however, results have been contradictory, with some studies reporting a negative and some reporting a positive relationship between the two. The goal of the current study was to further investigate how presence and cybersickness are related. Participants (N = 54) were exposed to a VR scene presented on a head-mounted display showing a 15-minute-long passive movement through space. The level of presence was manipulated by including an avatar (astronaut suit with hand-tracking) or no avatar in the virtual environment. Results showed that the avatar group reported significantly less severe cybersickness compared to the no-avatar group. We also found significant, negative correlations between some of the presence metrics (immersion, sensory fidelity) and cybersickness, indicating that cybersickness severity decreased as the level of presence increased. These findings suggest that more immersive VR experiences using an avatar may potentially reduce the risk of experiencing cybersickness.

Cortical brain potentials in response to lower limb proprioceptive stimuli in young adults with probable developmental coordination disorder

BackgroundProprioceptive deficits have been shown to underlie motor problems in individuals with a probable developmental coordination disorder (pDCD). Behavioral studies have employed response times to passive limb movement to evaluate proprioceptive function in individuals with pDCD. However, the underlying neural mechanisms involved in the cortical processing of proprioceptive input and its corresponding motor response are unclear. To address this issue, this study aims to investigate neuropsychological and neurophysiological performances using event-related potentials (ERP) on proprioceptive-motor tasks in young adults with pDCD. MethodsFrom a total of 149 young adults screened using the Bruininks-Oseretsky Test of Motor Proficiency 2nd Edition Complete Form (BOT-2), 12 individuals with pDCD were identified (mean age ± SD: 20.50 ± 1.08 years) along with 12 age- and sex-matched controls (mean age ± SD: 20.75 ± 1.05 years). Participants placed their dominant foot on a passive ankle motion apparatus that plantarflexed the ankle at a constant velocity of 22°/s for a total of 75 trials in each proprioceptive condition. With vision occluded, participants had to press the trigger button held by the dominant hand when they sensed the passive motion of the ankle (voluntary response, VR), or purely receive the movement without a voluntary response (non-voluntary response, NVR). Behavioral performances [i.e., mean movement detection time (MDTmean), the standard deviation of the movement detection time (MDTSD)] and ERP indices (i.e., N1, P3 amplitude, and latency) related to ankle kinesthetic stimuli were obtained to determine the proprioceptive-motor function. ResultsThe results showed that young adults with pDCD exhibited longer MDTmean (p < 0.001) and MDTSD (p = 0.002) compared to their controls. Electrophysiological indices measured at frontal and central electrode sites, showed that young adults with pDCD exhibited significantly smaller N1 (p = 0.019) and P3 amplitudes (p = 0.032) during VR and NVR conditions. Notably, correlation analysis revealed a significant negative relationship between MDTmean and N1 (r = 0.62, p < 0.001) and P3 amplitudes (r = − 0.55, p = 0.005) in the VR condition in young adults with and without pDCD. ConclusionsThis study sheds light on the central brain mechanisms underlying proprioceptive-motor deficits in young adults with pDCD. The combined analysis of behavioral and ERP data suggests that longer MDTmean and larger MDTSD in young adults with pDCD are associated with weaker proprioceptive afferent inflow shown by decreased N1 amplitude to the frontal and parietal cortices. Such degraded proprioceptive signals are followed by reduced P3 amplitude, suggesting that young adults with pDCD allocate fewer neural resources to modulate motor processes with regard to proprioceptive stimuli. These findings contribute to a better understanding of the neurophysiological basis of proprioceptive-motor deficits in pDCD and may inform the development of targeted sensorimotor interventions.

Laminar fMRI in the locked-in stage of amyotrophic lateral sclerosis shows preserved activity in layer Vb of primary motor cortex

Amyotrophic lateral sclerosis (ALS) affects the cerebral cortex layer-dependently, most notably by the foremost targeting of upper motor neurons (UMNs) sited in layer Vb. Previous studies have shown a retained ability of paralysed patients to activate cortical motor networks, even in late-stage ALS. However, it is currently unknown whether such activation reflects a retained capacity to process sensorimotor inputs or if it is a result of actual motor output. Given the distinct function of individual cortical layers, layer-specific functional measurements may provide insight to this question. In this study, using submillimetre resolution laminar fMRI, we assessed the layer-dependent activation associated with attempted (motor) and passive (somatosensory) movements in a locked-in stage ALS patient. We found robust activation in both superficial and deep layers of primary motor cortex (M1). The peak activation in deep layers was localised to layer Vb. These findings demonstrate preserved activity in deep output layers of M1, possibly reflecting a retained ability to engage surviving UMNs despite years of paralysis. Our study underscores the capacity of laminar fMRI to discern subtle cortical activity and elucidates a promising pathway for probing in vivo human ALS pathology with unprecedented resolution.

Physiotherapy and Rehabilitation in Geriatric Dogs and Cats

The word “geriatric” refers to the medicine of the elderly and it is used in veterinary medicine for animals that have completed 75% of their lifespan. As the size of an animal increases, the age at which they become geriatric decreases, therefore; geriatric age varies amongst different species and breeds. Homeostatic changes occur with increasing age and some diseases such as obesity, tumor formation, orthopedic disorders, cardiovascular disorders and neurological disorders are frequently seen. Some breeds are genetically predisposed to such diseases. Thus, regular screening tests and clinical examinations are important for early diagnosis. Geriatric physiotherapy is a developing field that is noninvasive and, in some cases, can be used as a form of primary treatment or supportive treatment. Physiotherapy prevents muscle atrophy and reduces pain caused by inflammation all the while improving the patient’s quality of life. There is a wide range of different methods used in physiotherapy; TENS and NMES devices, passive and active movement exercises, hydrotherapy, acupuncture, massage, laser therapy, ECSWT and cryotherapy. However, treatment protocols are tailored by physicians to fit each patient’s needs depending on the disease and severity of the disease to be treated.

Impairments in Proprioceptively-Referenced Limb and Eye Movements in Chronic Stroke.

Upper limb proprioceptive impairments are common after stroke and affect daily function. Recent work has shown that stroke survivors have difficulty using visual information to improve proprioception. It is unclear how eye movements are impacted to guide action of the arm after stroke. Here, we aimed to understand how upper limb proprioceptive impairments impact eye movements in individuals with stroke. Control (N = 20) and stroke participants (N = 20) performed a proprioceptive matching task with upper limb and eye movements. A KINARM exoskeleton with eye tracking was used to assess limb and eye kinematics. The upper limb was passively moved by the robot and participants matched the location with either an arm or eye movement. Accuracy was measured as the difference between passive robot movement location and active limb matching (Hand-End Point Error) or active eye movement matching (Eye-End Point Error). We found that individuals with stroke had significantly larger Hand (2.1×) and Eye-End Point (1.5×) Errors compared to controls. Further, we found that proprioceptive errors of the hand and eye were highly correlated in stroke participants (r = .67, P = .001), a relationship not observed for controls. Eye movement accuracy declined as a function of proprioceptive impairment of the more-affected limb, which was used as a proprioceptive reference. The inability to use proprioceptive information of the arm to coordinate eye movements suggests that disordered proprioception impacts integration of sensory information across different modalities. These results have important implications for how vision is used to actively guide limb movement during rehabilitation.

Combination of motor, sensory and affective tasks in an EEG paradigm for children with developmental disabilities

Individuals with neurodevelopmental disorders exhibit overlapping emotional, somatosensory and motor deficits. Although brain processes underlying these impairments have been extensively studied in a separate way, the brain interaction of these inputs is an innovative line of research. Here we present a new EEG methodology for exploring the interactive brain activity of sensorimotor and affective stimuli. The task consists in presenting affective stimuli of different modalities (e.g. affective pictures, affective touch) while simultaneously an arthromotor performs passive joint movements, unseen by the participant. Participants were then required to press one of two buttons to indicate if their joint position agreed with a picture shown in a screen. Pilot data of electroencephalography recordings revealed distinct somatosensory event-related potentials (SEP) when movement was subsequent to affective stimuli, compared to neutral stimuli, as well as a differentiation of SEPs for different neurodevelopmental conditions. Behavioral responses further showed that children with cerebral palsy had more errors to identify their hand position when they were exposed to affective stimuli. This paradigm is a valuable tool to explore the modulative influence of emotion in the sensorimotor brain processing of different populations with joint emotional and sensorimotor impairments, such as children with neurodevelopmental disorders or patients with stroke.•This method allows exploring the interaction between affective and sensoriomotor inputs in an EEG paradigm.

Tuina versus physiotherapy or a combination of both for the management of chronic nonspecific low back pain: A randomized controlled trial

ObjectiveTo rigorously evaluate the short-term and long-term effectiveness of Tuina (TN), alone and in combination with physiotherapy (PT), for Chronic nonspecific low back pain (CNLBP) through a comprehensive, high-quality clinical trial. MethodsThis randomized, single-blind trial was conducted from September 2020 to July 2023, involving 204 CNLBP patients from the First Affiliated Hospital of Jinan University. Participants underwent a baseline assessment, 6 treatment sessions over 8 weeks, a post-treatment evaluation in the 9th week, and a 20-week follow-up. Participants were randomly assigned to TN, PT, or a combination of TN and PT (TP) groups. Each treatment involved 6 sessions with a minimum 7-day interval, each lasting 30 minutes. Primary outcome was the change in Visual Analog Scale (VAS) for pain. Secondary outcomes included the Oswestry Disability Index (ODI), 36-Item Short Form Health Survey (SF-36), Range of Motion (ROM) of the spine, Traditional Chinese Medicine Syndrome Scale (TCMSS), and adverse events (AE). ResultsAmong the 204 participants, 67.16 % were female, and 88.73 % completed the 20-week follow-up. All groups showed significant reductions in VAS scores post-treatment and at follow-up. Secondary outcomes improved significantly, with notable decreases in ODI and TCMSS scores. Pairwise comparisons within groups indicated statistical significance, particularly in ODI scores, with clinical relevance. No significant differences were found between the groups. ROM and SF-36 showed statistical but not clinical significance. Only one AE (0.49 %) was reported, with no severe incidents. ConclusionAll treatment groups, including TN, TP, and PT, demonstrated significant reductions in VAS scores for CNLBP patients, with effects lasting up to 20 weeks. While TN and TP showed substantial improvements in secondary outcomes, particularly in ODI scores, no significant differences were found between the groups. These findings suggest that all treatments can be effective for managing CNLBP, supporting clinical practitioners in selecting appropriate interventions for patients, especially for those unable to engage in active exercises, utilizing passive movements like TN to enhance health outcomes.

Supra-inguinal fascia iliaca block versus peri-capsular nerve group (PNEG) block for pain management in patients with hip fracture: A double-blind randomised comparative trial

BackgroundRegional analgesia has been recommended to alleviate pain caused by hip fractures. Both the supra-inguinal fascia iliaca block (S-FIB) and the peri‑capsular nerve group (PENG) block provide better analgesia than conventional fascia iliaca block for patients with hip fractures, but which one is superior remains equivocal. This study aimed to determine the superiority of S-FIB or PENG block for patients awaiting hip surgery. MethodsIn this prospective, double-blind, randomised comparative trial, patients with hip fractures awaiting operation were randomly allocated to receive either S-FIB with 30 ml 0.35 % ropivacaine or PENG block with 20 ml 0.35 % ropivacaine. Primary outcomes were pain scores (numeric rating scale, NRS, 0–10) at rest and during passive movement 30 min after nerve block. Secondary outcomes included pain scores at rest and during movement 10 and 20 min after nerve block and during positioning for spinal anaesthesia, time spent for performing nerve block and spinal anaesthesia, and the quality of positioning for spinal anaesthesia. ResultsOne-hundred patients were enrolled and 91 patients completed the trial (S-FIB group n = 46, PENG group n = 45). No significant difference was noted between these two groups in the pain scores (median [interquartile range]) either at rest (0 [0–0] vs 0 [0–0], P = 0.151) or during passive movement (3 [1-6] vs 3 [2-5], P = 0.99) at 30 min after nerve block. However, within-group analysis revealed that a significant reduction in pain score at rest was noted as early as 20 min after PENG block while that was noted only at 30 min after S-FIB. In addition, less time was required to perform PENG than S-FIB the block (3.1 [2.3–3.9] vs. 4.6 [3.1–5.6] minutes, P < 0.001). ConclusionsOur result suggests that with a lower dose of local anaesthetic, a shorter procedure time and earlier analgesic effect, PENG block may be preferred to S-FIB for patients with hip fracture awaiting surgery.

Statin therapy improves locomotor muscle microvascular reactivity in patients with heart failure with preserved ejection fraction.

Peripheral microvascular dysfunction has been documented in patients with heart failure with preserved ejection fraction (HFpEF), which may be related to elevated levels of inflammation and oxidative stress. Unfortunately, few strategies have been identified to effectively ameliorate this disease-related derangement. Thus, using a parallel, double-blind, placebo-controlled design, this study evaluated the efficacy of 30-day atorvastatin administration (10 mg daily) on lower limb microvascular reactivity, functional capacity, and biomarkers of inflammation and oxidative stress in patients with HFpEF (statin, n = 8, 76 ± 6 yr; placebo, n = 8, 68 ± 9 yr). The passive limb movement (PLM)-induced hyperemic response and 6-min walk test (6MWT) distance were evaluated to assess ambulatory muscle microvascular function and functional capacity, respectively. Circulating biomarkers were also measured to assess the contribution of changes in inflammation and redox balance to these outcomes. The total hyperemic response to PLM, assessed as leg blood flow area under the curve (LBFAUC), increased following the statin intervention (pre, 60 ± 68 mL; post, 164 ± 90 mL; P < 0.01), whereas these variables were unchanged in the placebo group (P = 0.99). There were no significant differences in 6MWT distance following statin or placebo intervention. Malondialdehyde (MDA), a marker of lipid peroxidation, was significantly reduced following the statin intervention (pre, 0.68 ± 0.10; post, 0.51 ± 0.11; P < 0.01) while other circulating biomarkers were unchanged. Together, these data provide new evidence for the efficacy of low-dose statin administration to improve locomotor muscle microvascular reactivity in patients with HFpEF, which may be due, in part, to a diminution in oxidative stress.NEW & NOTEWORTHY This was the first study to investigate the impact of statin administration on locomotor muscle microvascular function in patients with HFpEF. In support of our hypothesis, the total hyperemic response to PLM, assessed as leg blood flow area under the curve, increased, and malondialdehyde, a marker of oxidative damage, was reduced following the statin intervention. Together, these data provide new evidence for the efficacy of statin administration to improve locomotor muscle microvascular reactivity in patients with HFpEF, which may be due, in part, to reduced oxidative stress.

Association Between Hip Translation and Hip Rotation and Anatomy: A Pilot Quasi-static MRI Study.

There is little known about translation of the hip and the relationship with hip rotation and morphology in asymptomatic patients. (1) Femoral head would exhibit significant translations in asymptomatic hips, (2) femoral head translations would correlate to femoral rotations, and (3) range of femoral head translations would correlate to hip morphology. Cross-sectional study; Level of evidence, 3. A total of 11 individuals (age, 23-47 years; 64% female) with asymptomatic hips underwent hip magnetic resonance imaging (MRI) in the following postures: neutral (supine), midflexion, maximum-flexion, internal rotation, internal rotation + midflexion, internal rotation + maximum-flexion, adduction, flexion-abduction-external rotation (FABER), extension, and lateral abduction. All rotations were passive. MRI-generated 3-dimensional hip models were used to quantify femoral rotations and translations. Femoral head diameter, acetabular diameter, lateral center-edge angle, alpha angle, femoral anteversion, acetabular version and inclination, and neck-shaft angle were measured from MRI. A t test was used if measured translations were statistically significant. Linear regression was used to assess the associations between translation and rotation. Pearson correlation was used to assess the relationships between hip anatomy and range of femoral head translations. In all tested positions, the femoral head translated anteriorly by 2 ± 1 mm (maximum 5 mm, P < .001), posteriorly by 1 ± 1 mm (maximum 6 mm, P < .001), superiorly by 2 ± 2 mm (maximum 7 mm, P < .001), inferiorly by 2 ± 2 mm (maximum 6 mm, P < .001), laterally by 1 ± 1 mm (maximum 4 mm, P < .001), and medially by 2 ± 1 mm (maximum 5 mm, P < .001), relative to the rested supine position. Femoral flexion was associated with posterior translation of the femoral head (P = .038). Femoral abduction was associated with medial translation of the femoral head (P = .042). Higher femoral anteversion and smaller alpha angle were associated with a higher total magnitude of femoral head translation in the anterior-posterior direction (P < .04). Smaller femoral anteversion, higher acetabular inclination, smaller lateral center-edge angle, and lower neck-shaft angle were associated with a higher total magnitude of femoral head translation in the superior-inferior direction (P ≤ .03). Our study demonstrated that, during passive physiologic movement, asymptomatic hips on average translated up to 2 mm (with up to 7 mm maximum translation in some positions), which is potentially related to hip rotations and morphology. Further investigations are warranted to understand the normal and pathologic hip translations and their impact on hip function (ie, instability and impingement).

Impaired Endothelial And Microvascular Functions In Obese Patients: Analysis Of Blood Flow In The Femoral Artery During Passive Leg Movements

Impaired Endothelial And Microvascular Functions In Obese Patients: Analysis Of Blood Flow In The Femoral Artery During Passive Leg Movements

Maintained volitional activation of the muscle alters the cortical processing of proprioceptive afference from the ankle joint

Cortical proprioceptive processing of intermittent, passive movements can be assessed by extracting evoked and induced electroencephalographic (EEG) responses to somatosensory stimuli. Although the existent prior research on somatosensory stimulations, it remains unknown to what extent ongoing volitional muscle activation modulates the proprioceptive cortical processing of passive ankle-joint rotations.Twenty-five healthy volunteers (28.8 ± 7 yr, 14 males) underwent a total of 100 right ankle-joint passive rotations (4° dorsiflexions, 4 ± 0.25 s inter-stimulus interval, 30°/s peak angular velocity) evoked by a movement actuator during passive condition with relaxed ankle and active condition with a constant plantarflexion torque of 5 ± 2.5 Nm. Simultaneously, EEG, electromyographic (EMG) and kinematic signals were collected. Spatiotemporal features of evoked and induced EEG responses to the stimuli were extracted to estimate the modulation of the cortical proprioceptive processing between the active and passive conditions.Proprioceptive stimuli during the active condition elicited robustly ∼26 % larger evoked response and ∼38 % larger beta suppression amplitudes, but ∼42 % weaker beta rebound amplitude over the primary sensorimotor cortex than the passive condition, with no differences in terms of response latencies.These findings indicate that the active volitional motor task during naturalistic proprioceptive stimulation of the ankle joint enhances related cortical activation and reduces related cortical inhibition with respect to the passive condition. Possible factors explaining these results include mechanisms occurring at several levels of the proprioceptive processing from the peripheral muscle (i.e. mechanical, muscle spindle status, etc.) to the different central (i.e. spinal, sub-cortical and cortical) levels.

Study on water entry impact characteristics and parameter influence analysis of the vehicle passing through the thin crushed ice zone in a polar environment

The problem of water entry in polar environments holds significant research value for polar resource exploration and military applications. This study uses computational fluid dynamics and the discrete element method (CFD-DEM) to investigate the complex process of a vehicle entering water through a thin crushed ice zone. Experimental data validates the efficiency of the coupling algorithm. The primary focus of this study is to investigate the influence of crushed ice shapes, arrangement patterns, coverage densities, and sizes within thin crushed ice zones on the process of water entry. A comprehensive analysis is carried out to assess how the characteristic parameters of different thin crushed ice zones affect the dynamic behavior of the vehicle during water entry and the movements of the crushed ice. Concurrently, the influence of different velocities of the vehicle on the water entry process through a specific thin crushed ice zone is analyzed. The results show that when the crushed ice is in a regular arrangement, it exhibits a circular immersion phenomenon and a cross-shaped passive movement trend. The arrangement patterns, coverage densities, and sizes of the crushed ice have different effects on the water entry process. Of these factors, the complexity of the influence of crushed ice sizes on the water entry process stands out. Meanwhile, the water entry velocity plays a crucial role in determining the relative significance of the hydrodynamic force and the collision force of crushed ice on the total resistance of the vehicle during water entry. These insights provide valuable guidance for the planning and execution of missions in polar regions.

The role of mouse tails in response to external and self-generated balance perturbations on the roll plane.

Chordate tails exhibit considerable morphological and functional diversity, with variations in length, diameter and texture adapted to various ecological roles. While some animals, including humans, have lost or reduced their tails, many vertebrates retain and use their tails for activities such as balancing, climbing and escaping predators. This study investigates how laboratory mice (Mus musculus) use their tails to maintain balance when dealing with external and self-generated perturbations. Mice crossed platforms of different widths, while responding to roll-plane tilts. Our findings show that mice swing their tails to counteract external roll perturbations, generating angular momentum to stabilize themselves. Mice were also found to use active (dynamic stabilizer) and passive (counterweight) tail movement strategies when locomoting on narrow platforms. The results suggest that the tail is a core component of mouse locomotion, especially in challenging balancing conditions.

Negative emotions reduce sensorimotor cortex activity during proprioceptive modulation of rolandic ∼20HZ beta rhythm in typically developing children and those with neurodevelopmental conditions

BackgroundThe Rolandic ∼20-Hz beta rhythm of the sensorimotor cortex is associated with motor function and perception. However, the modulation of this rhythm by different emotional stimuli is an innovative area of research. AimsThis study aims at investigating the impact of affective pictures (positive, negative, and neutral) on the proprioceptive modulation of the Rolandic ∼20 Hz beta rhythm in typically developing children and children with neurodevelopmental disorders (i.e. cerebral palsy and autism). Methods and proceduresEEG was recorded while participants experienced passive wrist movements during the simultaneous viewing of affective pictures. Time-frequency analysis of the sensorimotor oscillatory activity was performed. Outcomes and resultsOur findings revealed that pictures with negative emotional valence notably diminish event-related synchronization (ERS) amplitude during the perception of hand movement in all groups of children. Conclusions and implicationsThese findings suggest that emotional stimuli, particularly the negative ones, could significantly influence brain's processing of proprioception, adding knowledge to the interaction of common comorbidities, such as sensorimotor disorders and emotional dysregulation, in children with neurodevelopmental disabilities.

Microvascular effects of a mixed meal tolerance test: a model validation study

AbstractPurposeEndothelial dysfunction is a pathophysiological change preceding many cardiovascular events. Measuring improvements of endothelial function is challenging when function is already optimal, which may be remediated using a physiological challenge. This study aimed to determine whether imaging assessments can detect microvascular effects of a mixed meal tolerance test (MMTT).MethodsTwenty healthy volunteers (age ≥45 and ≤70 years) underwent two MMTTs at the beginning (Day 1) and end (Day 84) of a twelve‐week period. Imaging methods included laser speckle contrast imaging (LSCI) combined with post‐occlusive reactive hyperaemia (PORH) and local thermal hyperaemia (LTH) challenges, passive leg movement ultrasonography (PLM), and sidestream dark field microscopy (SDFM). Measurements were conducted pre‐MMTT and at 5 timepoints post‐MMTT for PLM and SDFM and 3 timepoints post‐MMTT for PORH and LTH.ResultsNo consistent effects of the MMTT were detected on LSCI LTH, PLM and SDFM endpoints. LSCI PORH maximum perfusion was significantly suppressed 46, 136, and 300 min post‐MMTT administration on Day 1, while residual perfusion decreased significantly 46 and 136 min post‐MMTT on Day 1. However, when repeated on Day 84, PORH endpoints were not significantly affected by the MMTT.ConclusionSDFM, PLM and LSCI LTH endpoints displayed high intra‐subject variability and did not detect consistent effects of MMTT. LSCI PORH endpoints displayed the lowest intra‐subject variability of all assessed endpoints and were affected by the MMTT on Day 1, but not on Day 84. Further standardization of methods or more robust challenges to affect vascular endpoints may be needed.