Recent innovations in technology including apps that transform virtual vestibular rehabilitation are described. The use of telehealth in the rehabilitation of people with vestibular disorders is relatively new. The advantages of telehealth for vestibular rehabilitation are described. There have been significant advances in technology that permit the clinician to prescribe a precise vestibular exercise prescription in the home. With new advances in the fidelity of cell phones and improvements in streaming capabilities, viewing body and eye movements virtually has greatly improved. New technology is expanding capabilities to rehabilitate people with vestibular disorders safely with online monitoring via the cloud.

Most fish are inherently unstable and must swim to stabilize posture. How diurnal fish reduce activity at night while maintaining postural control remains unclear. We defined distinct locomotor strategies that larval zebrafish (Danio rerio) use to control posture and navigate the water column in response to light and circadian cues. In the dark, larvae maintain balance by swimming in long bouts with large nose-up rotations, compensating for nose-down drift accrued during prolonged inactivity. Effective postural compensation requires vestibular sensation from the utricle. By contrast, in the light, larvae navigate with short, frequent and variable bouts. While lighting exerts a dominant, masking effect on the locomotor strategies, circadian rhythms modulate swim kinematics. Our results reveal distinct light-dark locomotor strategies and disentangle how ambient light and the internal clock jointly shape balance control and navigation. This work lays the foundation for understanding how external and internal cues interact to govern locomotor activity in freely moving diurnal animals.

Skeletal muscle architectural design strongly affects force-generating capacity and excursion range, and its functional importance to animal and human movement is well founded. Traditionally, this 'structure-function relation' has been inferred from architecture measurements with muscles at rest (from anatomical dissections or medical imaging techniques such as ultrasonography or magnetic resonance imaging) and muscle function tested under quasi-steady force conditions (e.g. isometric). A contemporary view recognises that, during active, dynamic contractions, muscles undergo load- and velocity-dependent changes in architecture and three-dimensional shape while remaining near-constant volume. Consequently, whole-muscle length change and velocity can become decoupled from fascicle length change and velocity, such that the whole muscle cannot be treated as a simple linear velocity transmission system but instead as a geared system where the input fascicle length change and velocity differ from the output whole muscle length change and velocity. This phenomenon is described by the concept of 'muscle gearing' and can be quantified as the ratio of the velocities or displacement of the muscle to the fascicle. Gear ratios are not fixed; instead, gear shifts with force and velocity, allowing the whole-muscle output to better match the mechanical demands of the task. Variable gearing is thought to emerge from load-dependent changes in fascicle angle and three-dimensional muscle deformations under volume-preserving and tissue constraints. Variable gearing has important functional implications, as it influences fascicle operating length and shortening velocity for a given task and thereby shifts where fascicles operate along their intrinsic force-length and force-velocity relationships. Through these effects, along with changes in the projection of fascicle force onto the muscle line of action as pennation varies, variable gearing can broaden whole-muscle force and power output across movement conditions. Accordingly, muscle gearing should be considered an integral component of a comprehensive framework for understanding dynamic muscle function in both normal and pathological states. Here, we synthesise evidence from animal and human studies to characterise variation in gearing across muscles, species and contraction conditions, and the factors that may underlie it. We use a previously validated three-dimensional finite-element muscle model to interrogate mechanisms that are difficult to isolate experimentally and, for the first time, demonstrate an effect of muscle activation on gearing. We also consider how ageing, injury and exercise training may alter gearing. Overall, muscle gearing has important functional implications, and our modelling demonstrates that it is an emergent property of the physics of muscle contraction.

Elucidating the neural computations underlying natural, complex movement remains a fundamental challenge in neuroscience. Bat flight presents a formidable motor control challenge, requiring hand-like wings whose many degrees of freedom must be precisely coordinated to enable rapid three-dimensional (3D) maneuvers. Here, we performed large-scale wireless recordings from the wing motor cortex of freely flying bats, combined with 3D tracking of wing kinematics. Despite the complexity of flight control, bats repeatedly executed accurate flights through precise adjustments of individual wingbeats. Surprisingly, motor cortical activity was not dominated by the wingbeat cycle. Instead, neurons were sparsely active, exhibiting mixed selectivity for flight kinematics and variable entrainment to the wingbeat phase reaching millisecond-scale precision. This yielded a high-dimensional population code driven by successive wingbeats occupying distinct neural states. These findings reveal a mode of motor cortical population dynamics expressed during natural dexterous movement that is not well captured by prevailing views derived from constrained paradigms.

Despite widespread use of in-ear music during running, its effects on ventilatory efficiency and biomechanics remain unclear. This study examined whether moderate-to-loud (85 dB SPL) in-ear tempo music affects ventilatory efficiency, running economy (RE), and spatiotemporal biomechanics during fixed-speed treadmill running, and whether responses differ by sex. Thirty-two recreationally active participants (15 women, 17 men; age 22.7±2.2 years) completed two randomized, counterbalanced sessions of 20-min treadmill running at 8 km·h⁻¹ with and without 128-bpm in-ear music. Breath-by-breath gas exchange, spatiotemporal gait parameters, and RPE were collected and analyzed via mixed-model ANOVA. In the whole sample, music induced a fast-shallow breathing pattern: breathing frequency rose by 10.0% and tidal volume fell by 4.6%, with a 5.5% increase in minute ventilation (V̇E; all p≤0.001). Ventilatory efficiency was reduced, with a 4.3% higher V̇E/V̇CO₂ and a 4.5% higher V̇E/V̇O₂ (both p<0.001). Biomechanics shifted toward a more aerial gait: stride time (+1.3%) and stride length (+1.0%; both p=0.002) increased, as did vertical oscillation (+30%, p=0.015) and flight time (+16%, p=0.002), while duty factor fell (-1.3%, p=0.006), with the aerial-gait shift more pronounced in women. Music also slightly raised RE (+1.1%; p=0.009). RPE was lower with music (12.7±2.6 vs. 13.4±2.4; p<0.001). Thus, moderate-to-loud in-ear music during treadmill running elicits an altered, fast-shallow ventilatory pattern that reduces ventilatory efficiency, also shifting running biomechanics toward a less economical pattern. The concurrent lowering of perceived exertion despite a slightly higher metabolic cost underscores a paradoxical dissociation between subjective effort and objective strain. Trial registration: NCT03506282.

Gallbladder cancer (GBC) is a prevalent and aggressive malignancy of the biliary system. Studies have revealed that Proteasome 26S subunit ATPase 2 (PSMC2) is overexpressed and associated with the development process of several cancers. However, the specific role in GBC remains unknown. This study aims to explore the association between PSMC2 and GBC pathogenesis. We assessed PSMC2 expression from normal and GBC patient samples. Using Cell Counting Kit-8 (CCK-8), colony formation, scratch, and Transwell migration assays, we investigated the effects of PSMC2 on the proliferation and migration of GBC cells. Subsequently, through bioinformatics analysis, we identified the cell cycle pathways related to PSMC2 in GBC cells. Using flow cytometry, we identified that knocking down PSMC2 could alter the cell cycle in GBC cells. Then, through bioinformatics analysis and Western blot assay, we discovered the relationship between the AKT/Cyclin D1/CDK6 pathway and the cell cycle and used an RAC-alpha serine/threonine-protein kinase (AKT) inhibitor and an Cyclin-Dependent Kinase 6 (CDK6) inhibitor to restore the GBC cell proliferation induced by PSMC2 overexpression in order to detect the mechanism of PSMC2's role in GBC. We found that PSMC2 was observably upregulated in GBC patient samples. In vitro experiments demonstrated that knocking down PSMC2 significantly suppressed the GBC cells' proliferation and migration abilities. Bioinformatics assays showed a significant enrichment of the cell cycle pathway in both the GO and KEGG databases. Furthermore, cell cycle-related genes CDK6 and Cyclin D1 were significantly upregulated in PSMC2-high expressed clusters. Then we identified that knockdown of PSMC2 could suppress AKT activation and reduce the expression of Cyclin D1 and CDK6. Moreover, treatment with the AKT inhibitor could restore the upregulated CDK6 expression after PSMC2 overexpression, and treatment with the CDK6 inhibitor restored the progression and altered the cell cycle distribution in GBC cells induced by PSMC2 overexpression. PSMC2 was significantly upregulated in GBC tissues and cell lines. PSMC2 expression promotes progression and migration in GBC cells, potentially through regulation of the AKT/Cyclin D1/CDK6 signaling pathway.

Dynamic alignment refers to the process of adjusting prosthetic components during the user's gait. Recently, there has been increasing focus on this area due to its critical role in restoring natural limb movement and meeting individual user needs. This review aims to examine the various devices, methods, and techniques reported in the literature for assessing dynamic alignment. The review is structured to address dynamic alignment in human prostheses, including techniques for measuring forces and moments, the effects on gait cycle parameters, external influences, and alignment adjustment devices. A key contribution of this review is highlighting aspects of optimal alignment, which are associated with improved gait stability, reduced compensatory movements, and decreased physical effort during walking. Advances in modern prosthetic devices, incorporating smart sensors and advanced algorithms, indicate a promising direction for the field. Current research also underscores the need for more precise and reliable mechanisms to perform dynamic alignment effectively.

AbstractClimate change is raising temperatures in aquatic habitats and shifting the frequency and severity of precipitation events. In fishes, metabolic demands increase under warmer conditions, which may limit the ability of fishes to survive the physical and metabolic demands of high-water flow events if extreme rainfall occurs during periods of high temperature. Here, we investigated how temperature affected the swimming performance, aerobic metabolism, and skeletal muscle phenotype of Amargosa River pupfish (Cyprinodon nevadensis amargosae) to explore how warmer temperatures may reduce the ability of pupfish to cope with fast-moving water. Adult pupfish were acclimated to 16°C, 27.5°C, or 35°C for 63-114 d, after which their swimming performance and metabolic rates were assessed using an intermittent swim-tunnel respirometry system. The critical swimming speed of pupfish increased from 7.9 body lengths (BL) s-1 at 16°C to 9.8 BL s-1 at 27.5°C but declined to 3.8 BL s-1 at 35°C. Paralleling those differences in swimming performance, maximum metabolic rate and aerobic scope were both lower at 35°C. Those differences in rates of oxygen consumption and swimming performance were accompanied by a shift in skeletal muscle metabolic phenotype, with muscle from pupfish at 35°C having reduced mitochondrial density, diminished citrate synthase activity, and ∼65%-80% reductions in relative messenger RNA abundances for citrate synthase and mitochondrion genes atpase6/8 and cox2. These results indicate that pupfish subjected to elevated temperatures experience reductions in skeletal muscle aerobic capacity and swimming performance, which may make these fish more vulnerable to fast-moving waters such as flash floods if those events occur at times of elevated temperature.