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Objectives: Despite qualitative observations of wild primates pumping branches before leaping across gaps in the canopy, most studies have suggested that support compliance increases the energetic cost of arboreal leaping, thus limiting leaping performance. In this study, we quantified branch pumping behavior and tree swaying in wild primates to test the hypothesis that these behaviors improve leaping performance. Materials and Methods: We recorded wild colobine monkeys crossing gaps in the canopy and quantitatively tracked the kinematics of both the monkey and the compliant support during behavioral sequences. We also empirically measured the compliance of a sample of locomotor supports in the monkeys' natural habitat, allowing us to quantify the resonant properties of substrates used during leaping. Results: Analyses of three recordings show that adult red colobus monkeys (Piliocolobus tephrosceles) use branch compliance to their advantage by actively pumping branches before leaping, augmenting their vertical velocity at take‐off. Quantitative modeling of branch resonance periods, based on empirical measurements of support compliance, suggests that monkeys specifically employed branch pumping on relatively thin branches with protracted periods of oscillation. Finally, an additional four recordings show that both red colobus and black and white colobus monkeys (Colobus guereza) utilize tree swaying to cross large gaps, augmenting horizontal velocity at take‐off. Discussion: This deliberate branch manipulation to produce a mechanical effect for stronger propulsion is consistent with the framework of instrumental problem‐solving. To our knowledge, this is the first study of wild primates which quantitatively shows how compliant branches can be used advantageously to augment locomotor performance. [ABSTRACT FROM AUTHOR]

Premaxillary protrusion and the performance advantages it confers are implicated in the success of diverse lineages of teleost fishes, such as Cypriniformes and Acanthomorpha. Although premaxillary protrusion has evolved independently at least five times within bony fishes, much of the functional work investigating this kinesis relates to mechanisms found only in these two clades. Few studies have characterized feeding mechanisms in less‐diverse premaxilla‐protruding lineages and fewer yet have investigated the distinctive anatomy underlying jaw kinesis in these lineages. Here, we integrated dissection, clearing and staining, histology, micro‐CT, and high‐speed videography to investigate an isolated and independent origin of jaw protrusion in the hingemouth, Phractolaemus ansorgii, which employs a complex arrangement of bones, musculature, and connective tissues to feed on benthic detritus via a deployable proboscis. Our goals were to provide an integrative account of the underlying architecture of P. ansorgii's feeding apparatus and to assess the functional consequences of this drastic deviation from the more typical teleost condition. Phractolaemus ansorgii's cranial anatomy is distinct from all other fishes in that its adducted lower jaw is caudally oriented, and it possesses a mouth at the terminal end of an elongated, tube‐like proboscis that is unique in its lack of skeletal support from the oral jaws. Instead, its mouth is supported primarily by hyaline‐cell cartilage and other rigid connective tissues, and features highly flexible lips that are covered in rows of keratinous unculi. Concomitant changes to the adductor musculature likely allow for the flexibility to protrude the mouth dorsally and ventrally as observed during different feeding behaviors, while the intrinsic compliance of the lips allows for more effective scraping of irregular surfaces. From our feeding videos, we find that P. ansorgii is capable of modulating the distance of protrusion, with maximum anterior protrusion exceeding 30% of head length. This represents a previously undescribed example of extreme jaw protrusion on par with many acanthomorph species. Protrusion is much slower in P. ansorgii—reaching an average speed of 2.74 cm/s—compared to acanthomorphs feeding on elusive prey or even benthivorous cypriniforms. However, this reorganization of cranial anatomy may reflect a greater need for dexterity to forage more precisely in multiple directions and on a wide variety of surface textures. Although this highly modified mechanism may have limited versatility over evolutionary timescales, it has persisted in solitude within Gonorynchiformes, representing a novel functional solution for benthic feeding in tropical West African rivers. [ABSTRACT FROM AUTHOR]

Background: Mandibular reconstruction patients often suffer abnormalities in the mandibular kinematics. In silico simulations, such as musculoskeletal modelling, can be used to predict post‐operative mandibular kinematics. It is important to validate the mandibular musculoskeletal model and analyse the factors influencing its accuracy. Objectives: To investigate the jaw opening‐closing movements after mandibular reconstruction, as predicted by the subject‐specific musculoskeletal model, and the factors influencing its accuracy. Methods: Ten mandibular reconstruction patients were enrolled in this study. Cone‐beam computed tomography images, mandibular movements, and surface electromyogram signals were recorded preoperatively. A subject‐specific mandibular musculoskeletal model was established to predict surgical outcomes using patient‐averaged muscle parameter changes as model inputs. Jaw bone geometry was replaced by surgical planning results, and the muscle insertion sites were registered based on the non‐rigid iterative closest point method. The predicted jaw kinematic data were validated based on 6‐month post‐operative measurements. Correlations between the prediction accuracy and patient characteristics (age, pathology and surgical scope) were further analysed. Results: The root mean square error (RMSE) for lower incisor displacement was 31.4%, and the error for peak magnitude of jaw opening was 4.9 mm. Age, post‐operative infection and radiotherapy influenced the prediction accuracy. The amount of masseter detachment showed little correlation with jaw opening. Conclusion: The mandibular musculoskeletal model successfully predicted short‐range jaw opening functions after mandibular reconstruction. It provides a novel surgical planning method to predict the risk of developing trismus. [ABSTRACT FROM AUTHOR]

Long‐term records of the flow patterns and dynamics of surge‐type glaciers improve our understanding of their underlying dynamic processes, and are critical to better resolve their contribution to a changing cryosphere. We adapt a modeling approach designed to emulate glacier surging and fold kinematics using the full Stokes ice‐flow model Elmer/Ice to simulate surging of the Dusty Glacier, located in the St. Elias Mountains, Canada. We combine distributed mass‐balance and numerical ice‐flow models to reconstruct the fold kinematics of the 2001–2003 surge of the Dusty Glacier by comparing model results to Landsat‐7 and Sentinel‐2 imagery, and assess the sensitivity of centennial‐scale modeled glacier structure to different mass balance and sliding parameterizations. This study demonstrates the feasibility of using the approach to reconstruct the surface structure kinematics of a surge‐type glacier in nature, highlighting its potential application to other surge‐type glaciers and regions. Plain Language Summary: Glaciers can exhibit irregular flow patterns that complicate predictions of their evolution over the coming decades and centuries. We present a method for reproducing iconic surface structures known as folded medial moraines using glaciological modeling. These moraines are wavy flow patterns found on surge‐type glaciers, highlighted by sediment deposited onto the ice that traces their path. By reconstructing these patterns, the underlying climate and sliding conditions that contributed to the glacier's past flow can be identified. Improving our knowledge of these conditions can help improve glacier flow models. We demonstrate that our methodology successfully reconstructs the flow patterns present on a large surge‐type glacier in Yukon, Canada, and explore its past flow history, and possible future, based on these results. Key Points: We use a distributed mass‐balance model and Elmer/Ice to reconstruct the 2001–2003 surge kinematics of the Dusty Glacier, Yukon, CanadaWe explore the centennial‐scale sensitivity of glacier surface fold geometry to mass balance and sliding parameterizationsThis study is a proof‐of‐concept for further model reconstructions of the past dynamics of surge‐type glaciers [ABSTRACT FROM AUTHOR]

Oblique convergence across the northern Qilian Shan is accommodated by sub‐parallel strike‐slip and thrust faults that ruptured simultaneously in the Mw 8 Gulang earthquake in 1927. We investigate the kinematics of fault loading in the northern Qilian Shan and provide insights into the conditions necessary for generating multi‐fault earthquakes. We perform Bayesian inversions for the geometry and creep rate on the fault network. We infer that all of the thrust faults are locked north of the Qilian‐Haiyuan strike‐slip fault and are accumulating elastic strain. Multi‐fault earthquakes may occurr in this fault system because the faults are simultaneously loaded by the same source of deformation and are linked together by locked fault segments. The interseismic velocity field alone can not contain the location or activity of individual faults visible in the geomorphology, therefore the short‐term geodetic measurements may not reliably indicate the long‐term behavior of the fault system. Plain Language Summary: This study aims to understand the earthquake hazard in the northern Qilian region of China. We use measurements of ground deformation between earthquakes to infer how the faults are being loaded in the region. We find that the ground deformation can be explained by a simple model with a single, slowly creeping fault at depth that loads all of the overlying faults. Large earthquakes that were caused by slip on many different faults at the same time have occurred in this region before. We suggest these so‐called "multi‐fault" earthquakes may occur because all of the faults are being simultaneously loaded by the same source of stress. Key Points: Oblique convergence in the northern Qilian Shan is accommodated by sub‐parallel thrust and strike‐slip faultingThe short‐term geodetic measurements do not constrain the thrust fault kinematics in the northern Qilian Shan over geological timescalesMulti‐fault earthquakes may be common in the region as all of the shallow thrust faults are linked together by locked fault segments [ABSTRACT FROM AUTHOR]

In this paper, we first give the basic information about octonions and present the Euclidean rotation matrix formed by an octonion in seven-dimensional Euclidean space. Next, we define and introduce the D7-module and dual vectors using dual numbers. Then, we provide the transformation that maps the points on the unit dual sphere one-to-one with the directed lines in R7. We also define a subset of the unit dual sphere, demonstrating that each element of this subset corresponds to two intersecting perpendicular directed lines in seven-dimensional Euclidean space. Following that, we introduce dual octonions with their basic algebraic properties and examine rigid body (screw) motions in seven-dimensional Euclidean space using dual octonions. Finally, we define an operator and express that this operator transforms two perpendicular intersecting directed lines in seven-dimensional Euclidean space into two perpendicular intersecting directed lines. [ABSTRACT FROM AUTHOR]

When manipulating objects, humans begin adjusting their grip force to friction within 100 ms of contact. During motor adaptation, subjects become aware of the slipperiness of touched surfaces. Previously, we have demonstrated that humans cannot perceive frictional differences when surfaces are brought in contact with an immobilised finger, but can do so when there is submillimeter lateral displacement or subjects actively make the contact movement. Similarly, in, we investigated how humans perceive friction in the absence of intentional exploratory sliding or rubbing movements, to mimic object manipulation interactions. We used a two‐alternative forced‐choice paradigm in which subjects had to reach and touch one surface followed by another, and then indicate which felt more slippery. Subjects correctly identified the more slippery surface in 87 ± 8% of cases (mean ± SD; n = 12). Biomechanical analysis of finger pad skin displacement patterns revealed the presence of tiny (<1 mm) localised slips, known to be sufficient to perceive frictional differences. We tested whether these skin movements arise as a result of natural hand reaching kinematics. The task was repeated with the introduction of a hand support, eliminating the hand reaching movement and minimising fingertip movement deviations from a straight path. As a result, our subjects' performance significantly declined (66 ± 12% correct, mean ± SD; n = 12), suggesting that unrestricted reaching movement kinematics and factors such as physiological tremor, play a crucial role in enhancing or enabling friction perception upon initial contact. Key points: More slippery objects require a stronger grip to prevent them from slipping out of hands.Grip force adjustments to friction driven by tactile sensory signals are largely automatic and do not necessitate cognitive involvement; nevertheless, some associated awareness of grip surface slipperiness under such sensory conditions is present and helps to select a safe and appropriate movement plan.When gripping an object, tactile receptors provide frictional information without intentional rubbing or sliding fingers over the surface. However, we have discovered that submillimeter range lateral displacement might be required to enhance or enable friction sensing.The present study provides evidence that such small lateral movements causing localised partial slips arise and are an inherent part of natural reaching movement kinematics. [ABSTRACT FROM AUTHOR]

Background: Unbalanced alterations of temporomandibular joint morphology were associated with unilaterally masticatory habits. Objective: This study aimed to investigate the effect of unilateral mastication on the remodelling of the temporomandibular joint using dynamic joint space. Methods: Twelve volunteers with non‐maxillofacial deformity and healthy temporomandibular joints were recruited. The 3D models of the mandible and the maxilla were reconstructed according to computed tomography. The subjects were asked to masticate French fries and peanuts unilaterally, which was recorded by a 3D motion capture system. The dynamic joint space during unilateral mastication was analysed. Results: During early closure, the joint space reduction on the non‐masticatory side was significantly greater than on the masticatory side (p <.05). During later closure, the joint space reduction on the non‐masticatory side was significantly lower than that on the masticatory side (p <.05). The difference in joint space reduction between both sides was greater than the French fries while masticating the peanuts. Conclusions: Unilateral mastication resulted in a different major pressure area on the bilateral TMJs. Therefore, unilateral mastication might be an essential factor in the bilateral asymmetrical remodelling of the TMJ. [ABSTRACT FROM AUTHOR]

Background: Kinematic driving data studies are a novel methodology relevant to health care, but prior studies have considerable variance in their methods, populations, and findings suggesting a need for critical analysis and appraisal for feasibility and methodological guidelines. Methods: We assessed kinematic driving studies of adults with chronic conditions for study feasibility, characteristics, and key findings, to generate recommendations for future study designs, and to identify promising directions for applications of kinematic driving data. PRISMA was used to guide the review and searches included PubMed, CINAHL, and Compendex. Of 379 abstract/titles screened, 49 full‐text articles were reviewed, and 29 articles met inclusion criteria of analyzing trip‐level kinematic driving data from adult drivers with chronic conditions. Results: The predominant chronic conditions studied were Alzheimer's disease and related Dementias, obstructive sleep apnea, and diabetes mellitus. Study objectives included feasibility testing of kinematic driving data collection in the context of chronic conditions, comparisons of simulation with real‐world kinematic driving behavior, assessments of driving behavior effects associated with chronic conditions, and prognostication or disease classification drawn from kinematic driving data. Across the studies, there was no consensus on devices, measures, or sampling parameters; however, studies showed evidence that driving behavior could reliably differentiate between adults with chronic conditions and healthy controls. Conclusions: Vehicle sensors can provide driver‐specific measures relevant to clinical assessment and interventions. Using kinematic driving data to assess and address driving measures of individuals with multiple chronic conditions is positioned to amplify a functional outcome measure that matters to patients. [ABSTRACT FROM AUTHOR]

To be a quantitative and testable tectonic model, plate tectonics requires spherical geometry and spherical kinematics in terms of finite rotations conveniently parametrized by their angle and axis and described by unit quaternions. In treatises on "Plate Tectonics" infinitesimal, instantaneous, and finite rotations, absolute and relative rotations are said to be applied to model the motion of tectonic plates. Even though these terms are strictly defined in mathematics, they are often casually used in geosciences. Here, their definitions are recalled and clarified as well as the terms rotation, orientation, and location on the sphere. For instance, infinitesimal rotations refer to a mathematical limit, when the angle of rotation tends to zero. Their rules do not apply to finite rotations, no matter how small their finite angles of rotation are. Mathematical approaches applying appropriate and feasible assumptions to model spherical motion of tectonic plates over geological times of hundreds of millions of years are derived including (i) sequences of incremental finite rotations, (ii) sequences of accumulating successive concatenations of finite rotations, and (iii) continuous rotations in terms of fully transient quaternions. The incremental and the accumulating approaches provide complementary views. While the relative Euler pole appears to migrate in the latter, it appears fixed in the former. Path, mean, and instantaneous velocity of the migrating Euler pole are derived as well as the angular and trajectoral velocity of the rotational motion about it. The approaches are illustrated by a geological example with actual data and a numerical yet geologically inspired example with artificial data. The former revisits the three‐plate scenario with stationary axes of two "absolute" rotations implying transient "relative" rotations about a migrating Euler pole and employs a proper plate‐circuit argument to determine them numerically without resorting to approximations. The latter applies an involved interplay of incremental and accumulating modeling inducing split–join cycles to approximate sinusoidal trajectories as reported to record plates' motion during the Gondwana breakup. [ABSTRACT FROM AUTHOR]

The structural connectivity and kinematic relationship between the Altyn Tagh sinistral strike‐slip fault (ATF) and Qilian Shan fold‐and‐thrust belt along the north Tibetan margin east of 96°E is an important question for tectonicists interested in the evolving active deformation field of Central Asia and associated earthquake hazards of China's Hexi Corridor region. New results from a detailed 130‐km‐long N‐S magnetotelluric (MT) survey from the Qilian Shan to Beishan elucidates the locations and down‐dip orientations of major faults. Importantly, the results indicate that the Heishan‐Jinta'Nanshan fault system roots steeply into the lower crust, is unconnected to the Qilian Shan thrust wedge, and has reactivated the margin of the North China Craton and an older, regional ductile shear belt. The structurally linked ATF‐Heishan‐Jinta'Nanshan system defines a fundamental kinematic boundary in central Asia between the NE directed Qilian Shan thrust belt to the south and the eastwardly extruding Beishan‐Alxa Block to the north. Plain Language Summary: In this study, we present results of a comprehensive electrical resistivity survey conducted in the western Hexi Corridor region of China. The survey reveals significant sub‐surface faults and crustal boundaries, providing insights into the crustal structure between northernmost Tibet (Qilian Shan) and the Beishan. We document how the strike‐slip crustal boundary known as the Altyn Tagh Fault (ATF)‐Heishan‐Jinta'Nanshan system is steep and spatially unconnected to the Qilian Shan east of 98°E. It separates crustal blocks with contrasting motion histories; the southern block experiences compressional deformation, whereas the northern block accommodates extensional and transtensional deformation. Furthermore, the northeast trending ATF bends and converges into the more east‐west‐oriented Heishan‐Jinta'Nanshan system. We propose that this is a result of the Heishan‐Jinta'Nanshan system reactivating an older ductile shear belt and a mechanically weak boundary along the northwestern margin of the Precambrian North China Craton. Our study confirms the significance of inherited crustal structures in localizing continental interior reactivation and associated earthquake hazards. Key Points: A new detailed 3D resistivity model from Northern Tibet to the Southern Beishan clarifies the crustal structure in the NW Hexi CorridorThe Heishan fault system penetrates steeply to the lower crust and is unconnected to the Qilian Shan thrust wedgeCrustal thickening and mountain uplift in Qilian Shan is kinematically separated from eastward Beishan‐Alxa Block extrusion further north [ABSTRACT FROM AUTHOR]

In this manuscript, the advancement of one‐dimensional shock waves propagating through a non‐ideal reacting gas is examined. Considering the shock wave as a propagating discontinuity surface, a pair of evolution equations describing the strength of the shock and the first‐order discontinuity for variable initial data are obtained. The truncation approximations are used to obtain the exponent of shock velocity for the case of strong shock with constant initial data and compared with those exponents obtained from Guderley's scheme and Chisnell–Chester–Whitham (CCW) rule. The effects of non‐ideal and reaction parameters on the shock evolution in the case of arbitrary shock strength are examined and compared with those obtained from the CCW rule. Furthermore, the global behaviors of shock strength and induced discontinuity for different values of non‐ideal and reaction parameters are analyzed. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the utility and applicability of electrooculography (EOG) when studying ocular activity during complex motor behavior. Due to its lower spatial resolution relative to eye tracking (ET), it is unclear whether EOG can provide valid and accurate temporal measurements such as the duration of the Quiet Eye (QE), that is the uninterrupted dwell time on the visual target prior to and during action. However, because of its greater temporal resolution, EOG is better suited for temporal‐spectral decomposition, a technique that allows us to distinguish between lower and higher frequency activity as a function of time. Sixteen golfers of varying expertise (novices to experts) putted 60 balls to a 4‐m distant target on a flat surface while we recorded EOG, ET, performance accuracy, and putter kinematics. Correlational and discrepancy analyses confirmed that EOG yielded valid and accurate QE measurements, but only when using certain processing parameters. Nested cross‐validation indicated that, among a set of ET and EOG temporal and spectral oculomotor features, EOG power was the most useful when predicting performance accuracy through robust regression. Follow‐up cross‐validation and correlational analyses revealed that more accurate performance was preceded by diminished lower‐frequency activity immediately before movement initiation and elevated higher‐frequency activity during movement recorded from the horizontal channel. This higher‐frequency activity was also found to accompany a smoother movement execution. This study validates EOG algorithms (code provided) for measuring temporal parameters and presents a novel approach to extracting temporal and spectral oculomotor features during complex motor behavior. This study validates electrooculography for computing temporal indices of oculomotor activity typically obtained through mobile eye tracking. It also indicates that using EOG indices that embed both temporal and spectral features can improve predictions of movement accuracy compared to those that rely on temporal features only. [ABSTRACT FROM AUTHOR]

Background: Prior studies investigated selected discrete sagittal‐plane outcomes (e.g., peak knee flexion) in relation to running economy, hereby discarding the potential relevance of running technique parameters during noninvestigated phases of the gait cycle and in other movement planes. Purpose: Investigate which components of running technique distinguish groups of runners with better and poorer economy and higher and lower weekly running distance using an artificial neural network (ANN) approach with layer‐wise relevance propagation. Methods: Forty‐one participants (22 males and 19 females) ran at 2.78 m∙s−1 while three‐dimensional kinematics and gas exchange data were collected. Two groups were created that differed in running economy or weekly training distance. The three‐dimensional kinematic data were used as input to an ANN to predict group allocations. Layer‐wise relevance propagation was used to determine the relevance of three‐dimensional kinematics for group classification. Results: The ANN classified runners in the correct economy or distance group with accuracies of up to 62% and 71%, respectively. Knee, hip, and ankle flexion were most relevant to both classifications. Runners with poorer running economy showed higher knee flexion during swing, more hip flexion during early stance, and more ankle extension after toe‐off. Runners with higher running distance showed less trunk rotation during swing. Conclusion: The ANN accuracy was moderate when predicting whether runners had better, or poorer running economy, or had a higher or lower weekly training distance based on their running technique. The kinematic components that contributed the most to the classification may nevertheless inform future research and training. [ABSTRACT FROM AUTHOR]

We investigated the acute effects of caffeine supplementation (6 mg･kg−1) on 60‐m sprint performance and underlying components with a step‐to‐step ground reaction force measurement in 13 male sprinters. After the first round sprint as a control, caffeine supplementation‐induced improvement in 60‐m sprint times (7.811 s at the first versus 7.648 s at the second round, 2.05%) were greater compared with the placebo condition (7.769 s at the first versus 7.768 s at the second round, 0.02%). Using average values for every four steps, in the caffeine condition, higher running speed (all six step groups), higher step frequency (5th–16th and 21st–24th step groups), shorter support time (all the step groups except for 13th–16th step) and shorter braking time (9th–24th step groups) were found. Regarding ground reaction forces variables, greater braking mean force (13th–19th step group), propulsive mean force (1st–12th and 17th–20th step groups), and effective vertical mean force (9th–12th step group) were found in the caffeine condition. For the block clearance phase at the sprint start, push‐off and reaction times did not change, while higher total anteroposterior mean force, average horizontal external power, and ratio of force were found in the caffeine condition. These results indicate that, compared with placebo, acute caffeine supplementation improved sprint performance regardless of sprint sections during the entire acceleration phase from the start through increases in step frequency with decreases in support time. Moreover, acute caffeine supplementation promoted increases in the propulsive mean force, resulting in the improvement of sprint performance. [ABSTRACT FROM AUTHOR]

Background: Occlusal interferences lead to changes in mandibular kinematics to compensate and improve function. However, the effects of different types of eccentric disturbance on the comminution capacity are not known. Objective: To determine the immediate effect of eccentric occlusal interferences on masticatory performance. Methods: This crossover clinical trial included 12 healthy dentate subjects aged 25.2 ± 3.3 years who were randomly submitted to seven types of occlusal interference: unilateral and bilateral laterotrusive and mediotrusive, protrusive, dummy and control (no interference). The interference forms were planned in a semi‐adjustable articulator, fabricated with composite resin and adhered to the mandibular first molars such that subjects' maximum intercuspation was maintained. Masticatory performance and the chewing rate during 20 cycles were evaluated during subjects' comminution of silicone test food under one interference condition per test day; the multiple sieve method was applied to the comminuted particles. The interference was removed upon test completion, and a 1‐week washout period was applied between tests. Results: Comminuted median particle sizes were larger under unilateral (4.94 ± 0.41 mm) and bilateral (4.81 ± 0.49 mm) laterotrusive, bilateral mediotrusive (4.65 ± 0.50 mm) and protrusive (4.83 ± 0.54 mm) interferences (p <.05) than under the control (4.01 ± 0.52 mm) and dummy (4.18 ± 0.58 mm) conditions (p <.05). Only unilateral and bilateral laterotrusive interferences narrowed the comminuted particle size dispersion (p <.05). The chewing rate did not differ among conditions (p =.1944). Conclusion: Artificial eccentric interferences had an immediate adverse effect on masticatory performance by resulting in larger comminuted particles. Clinical trial registration: Brazilian Registry of Clinical Trials (RBR‐8g5zfg8). [ABSTRACT FROM AUTHOR]

Objective: Food avoidance is central to patients with anorexia nervosa‐restrictive type (AN‐R). Competing accounts in experimental psychopathology research suggest that food avoidance may result from automatic, habitual responses or from elevated inhibitory control abilities. This study investigated behavioral trajectories of food avoidance in a novel virtual reality stopping task. Method: Sixty patients with AN‐R and 29 healthy controls with normal weight were investigated using a novel, kinematic task in virtual reality. We recorded spatial displacement in stop‐ and go‐trials to virtual food and control objects. Inhibitory control abilities were operationalized by the VR task in stopping performance (i.e., interrupted movement in stop‐trials), whereas we also measured habitual avoidance of virtual food across both go‐ and stop‐trials (i.e., delayed movement relative to nonfood objects). Results: In patients with AN‐R, hand displacements were shorter to food versus nonfood across stop‐ and go‐trials, reflected in a Stimulus × Group interaction. Healthy controls showed no differences. Importantly, the food‐specific effect in AN‐R was identical across stop‐ and go‐trials, indicating habitual food avoidance. Moreover, stop error rates (i.e., stop‐trials with response) were lower in patients with AN‐R. Discussion: The findings suggest food‐specific habitual avoidance and heightened generalized inhibitory control in AN‐R. The continuously delayed displacements during active hand movements across stop‐ and go‐trials indicated the persistence of patients' avoidance of food. Public Significance: Experimental research investigates the mechanisms underlying mental disorders such as anorexia nervosa. In this study, we measured interrupted hand movements in response to food pictures or neutral pictures (shoes) in patients with anorexia nervosa and healthy controls. A virtual reality scenario was used. Findings indicated that patients were slower at approaching food, interrupted or not. Key mechanisms of food avoidance can be translated into habit‐based treatment options in future research. [ABSTRACT FROM AUTHOR]

The Banda arc‐continent collision zone signifies one of the most seismically active and tectonically intricate zones. The high convergence rate across the region, coupled with the exceptionally arcuate arc and subducted slab, makes it an ideal locale for investigating interactions between plate (slab) kinematics and plastic flow in the asthenosphere, which can be diagnosed by seismic anisotropy from shear wave splitting analyses. In total, 206 pairs of splitting measurements using teleseismic SKS, SKKS, and PKS, along with 43 pairs using local S phases, are obtained by utilizing broadband seismic data from five permanent seismic stations. To reduce the ambiguity in determining the origin of anisotropy leading to the teleseismic splittings, which lack vertical resolution, crustal anisotropy is constrained according to the sinusoidal moveout of converted S phases at the Moho using receiver functions. A layered anisotropic structure based on joint analyses of the anisotropy measurements characterizing different depth layers suggests the presence of trench‐parallel flow both in the mantle wedge and the sub‐slab region. The northeastward motion of the slab, entrained by the fast‐moving Australian Plate, deflects asthenospheric materials. The modulation results in trench‐parallel plastic mantle flows and leads to the steepening of the southern portion of the asymmetric spoon‐shaped Banda slab. In the shallower part of the sub‐slab region, the northeastward Australian Plate motion produces simple shear in the transitional layer between the rigid lithosphere and the viscous asthenosphere. The shear deformation induces seismic anisotropy with resulting fast orientations in accordance with the plate motion direction. Plain Language Summary: The Banda region represents a nascent arc‐continent collision with the Australian continental lithosphere. The volcanic arc and non‐volcanic arc‐islands display a unique horseshoe shape. The subducted slab is anomalously bent 180°, leading to a spoon‐shaped morphology with a steeper southern portion. The role of the kinematics of the Australian Plate and this bent slab in shaping the asthenosphere is not clear. This study uses seismic anisotropy measured using data recorded over 14 years by five broadband seismic stations on the non‐volcanic arc‐islands to explore this intriguing problem. Results suggest that the northeastward movement of the Australian Plate makes asthenospheric materials flow along the depth contour of the slab, steepening the Banda slab's southern part. In the sub‐slab region, the upper portion follows the movement direction of the Australian Plate, while the deeper part is influenced more by slab deflection, directing asthenospheric flow. Key Points: Mantle flow field associated with the spoon‐shaped Banda slab is investigated using seismic azimuthal anisotropy measurementsObservations can be explained by trench‐parallel flow both in the mantle wedge and the sub‐slab regionNortheastward movement of the slab relative to the asthenosphere induces the two flow systems and leads to steepening of the southern slab [ABSTRACT FROM AUTHOR]

The slow spreading Reykjanes Ridge overlies the Iceland hotspot and has undergone well ordered changes in crustal segmentation. Previous studies have attributed these changes to varying mantle plume thermal effects, rendering the lithosphere ductile or brittle. Here we use seafloor spreading magnetic anomalies to show that crustal accretion has been focused throughout its spreading history and to determine the detailed evolution of Reykjanes Ridge segments. By ∼53 Ma, organized spreading had developed on an orthogonally spreading linear axis following continental breakup. After a plate motion change at ∼38 Ma, orthogonally spreading offset ridge segments formed by ridge propagation forming varying length fracture zones. From then to the present, the offset segments diachronously migrated back to the original linear geometry from north to south replacing orthogonal with oblique spreading as the axis became linear again. Fracture zones were not terminated, however, simply by reducing segment offsets even to zero. Their termination involved the axial propagation of buoyant upwelling instabilities across the discontinuities, correspondingly extending V‐shaped crustal ridges southward. This evolution was guided by a persistent linear deep damp mantle melting interval maintained by the episodic propagation of buoyant upwelling instabilities. Our study indicates that at slow spreading ridges, where buoyant upwelling instabilities govern crustal segmentation, spatial gradients in mantle melting properties may direct the behavior of the instabilities. Where ridges overlie regional hotspot gradients in mantle melting, buoyant instabilities may propagate systematically, and plate boundary evolution may follow an organized pattern. Plain Language Summary: As the Reykjanes Ridge overlies the Iceland hotspot, much of its evolution has been proposed to reflect varying mantle plume thermal effects. Here we use seafloor spreading magnetic lineations to study this evolution and better understand controlling mechanisms. We find that typical plate tectonic processes can account for the evolution without resorting to changing mantle plume thermal effects. However, a persistent regional gradient in mantle melting associated with the Iceland hotspot strongly directs the evolution. The ridge originated as a linear axis. It became fragmented by rift propagation following a plate motion change. The offset segments then progressively reassembled their original linear geometry by asymmetric spreading. Axial propagation of buoyant upwelling instabilities terminated fracture zones when segment offsets became small. This evolution was guided by a deep zone of mantle melting that remained linear, maintained by axially propagating buoyant instabilities that also form V‐shaped crustal ridge on the ridge flanks. Our study indicates that at slow spreading ridges where buoyant mantle upwellings govern crustal segmentation, factors that influence mantle melting can direct the motion of the instabilities. Where hotspots form pronounced along‐axis melting gradients, buoyant upwelling centers and crustal segmentation can follow an organized evolution. Key Points: Overlying the Iceland hotspot, the Reykjanes Ridge underwent a remarkably organized plate boundary evolutionThe linear ridge became fragmented following a plate motion change then systematically reassembled its original linear configurationThe Iceland hotspot melting gradient causes buoyant mantle upwelling cells to propagate, reestablishing the original linear axis [ABSTRACT FROM AUTHOR]

Ankle inversion orientation and peroneal activation insufficiency may contribute to lateral ankle sprains during landing in chronic ankle instability (CAI); however, how anticipation alters these factors is neglected. This study aimed to assess the impact of anticipation on joint orientation and muscle activity during landing in individuals with CAI. Fifteen participants with CAI and 15 healthy participants (control) were recruited to perform single‐leg landings after bilateral countermovement jumps when the landing limb was specified before (planned) or after (unplanned) take‐off. Joint angle (hip, knee, and ankle) and electromyography (gluteus medius, rectus femoris, biceps femoris, gastrocnemius lateral head, tibialis anterior, and peroneal longus) were collected and analyzed with 2 (groups) × 2 (conditions) statistical parametric mapping ANOVA. In the unplanned condition, the CAI group demonstrated a less plantarflexed (maximum difference [MD] = 9.5°, p = 0.047) and more inverted ankle joint (MD = 4.1°, p < 0.001) before ground contact, along with lower peroneal activity at ground contact compared to the control group (MD = 28.9% of peak activation, p < 0.001). No significant differences between groups were observed in the planned condition. In conclusion, anticipation may mask jump landing deficits in people with CAI, including inverted ankle orientation and reduced peroneus longus activity pre‐ and post‐landing, which were observed exclusively in unplanned landings. Clinicians and researchers need to recognize the impact of anticipation on apparent landing deficits and consider the implications for injury prevention and rehabilitation strategies. [ABSTRACT FROM AUTHOR]

The aim of this study was to understand the interactions between anthropometric, kinetic, and kinematic variables and how they determine the 100 m freestyle performance in young swimmers. Twenty‐five adolescent swimmers (15 male and 10 female, aged 15.75 ± 1.01 years) who regularly participated in regional and national competitions were recruited. The 100 m freestyle performance was chosen as the variable to be predicted. A series of anthropometric (hand surface area–HSA), kinetic (thrust and active drag coefficient (CDA)), and kinematic (stroke length (SL); stroke frequency (SF), and swimming speed) variables were measured. Structural equation modeling (via path analysis) was used to develop and test the model. The initial model predicted performance with 90.1% accuracy. All paths were significant (p < 0.05) except the thrust—SL. After deleting this non‐significant path (thrust—SL) and recalculating, the model goodness‐of‐fit improved and all paths were significant (p < 0.05). The predicted performance was 90.2%. Anthropometrics had significant effects on kinetics, which had significant effects on kinematics, and consequently on the 100 m freestyle performance. The cascade of interactions based on this path‐flow model allowed for a meaningful prediction of the 100 m freestyle performance. Based on these results, coaches and swimmers should be aware that the swimming predictors can first meaningfully interact with each other to ultimately predict the 100 m freestyle performance. [ABSTRACT FROM AUTHOR]

With the help of plane geometric algebra, we see volumetric errors as pure geometric objects. We use this identification to expand errors with respect to Abbe's principle into the whole working space with respect to some additional conditions. We show that geometric algebra helps us to understand errors in kinematics chains. We demonstrate our approach on a model example. [ABSTRACT FROM AUTHOR]

Background and Objective: Upper extremity impairment is one of the complications in hemiplegic children. The purpose of modified constraint‐induced movement therapy (mCIMT) is to improve the function of impaired arms and hands in these children. This study compared the efficacy of mCIMT and the approach of neurodevelopmental therapy (NDT) on reaching capacity in children with spastic hemiplegia. Methods: Fifty‐two spastic hemiplegic children ranging in age from four to 6 years were selected for this study from an outpatient clinic and biomechanical lab (Prince Sattam bin Abdulaziz University, KSA). They were randomly divided into two experimental groups: group I received NDT and group II received mCIMT for the involved upper limb and restriction of the uninvolved arm movements for 12 weeks (three times per week). Both groups received a conventional exercise program in addition to experimental one. Active elbow extension range of motion and three‐dimensional motion analysis of the reaching task were measured before and after 3 months of treatment. Results: Significant enhancement in all pre‐treatment and post‐treatment outcomes was observed in both groups by a two‐way mixed MANOVA; furthermore, Group II (mCIMT) showed the most significant improvement (elbow extension, percentage of reach to peak velocity, movement time and movement units) when comparing the post‐treatment outcomes between the two groups (p < 0.001). Implication for Physiotherapy Practice: Addition of mCIMT to a conventional exercise was superior to adding NDT exercise therapy in promoting the performance of reaching pattern in hemiplegic children. [ABSTRACT FROM AUTHOR]

Background: The aims of the present umbrella review were (a) to summarize the available evidence on the effectiveness of mobile applications aimed at increasing physical activity; (b) to analyse the effect of an increase in physical activity on kinanthropometric variables, body composition and physical fitness of adolescents aged 12–16 years old; and (c) to determine the strengths and limitations of the interventions carried out with adolescents aged 12–16 years old through the use of mobile applications, to provide recommendations for future research. Methods: The most relevant inclusion criteria were (a) adolescents aged 12–16 years old; (b) interventions carried out only with mobile apps; (c) pre‐post measurements; (d) participants without illnesses or injuries; and (e) interventions lasting more than 8 weeks. The databases used to identify the systematic reviews were the Web of Science, Google Scholar, PubMed and Scopus. Two reviewers independently used the AMSTAR‐2 scale to measure the methodological quality of the included reviews and also carried out an analysis of external validity, with a third reviewer participating in the cases in which consensus was not reached. Results: A total of 12 systematic reviews were included (these included a total of 273 articles that used electronic devices, of which 22 studies exclusively used mobile applications with adolescents aged 12–16). Regarding physical activity and its effect on body composition, kinanthropometric variables and physical fitness, no significant differences were found for any of the variables analysed, and the results were not sufficiently consistent to determine the influence of these interventions. Conclusions: It is important to highlight that the scientific research conducted so far showed that mobile applications were not effective in increasing physical activity and changing the kinanthropometric variables, body composition or physical fitness of adolescents. Thus, future research with stronger methodological rigour and larger samples is needed to provide stronger evidence. [ABSTRACT FROM AUTHOR]

Objectives: Although a bounding gait is practiced by a diversity of animals, the morphological characteristics, kinematics, and energetics associated with this locomotor form remain poorly understood. This study focuses on the locomotor anatomy of two species of African colobine monkeys (Piliocolobus badius, a leaper, and Colobus polykomos, a leaper–bounder) in an effort to assess if bounding should be considered a unique primate locomotor category or is better viewed as a behavior on a leaping continuum. Materials and Methods: A total of 53 femora, 28 humeri, and 45 ossa coxae from the two species provide comparative morphological data. Free‐body models of bounding and leaping are presented to characterize loading conditions. Species differences in morphometric traits are evaluated via parametric and nonparametric tests (i.e., analysis of variance, resampling). Results: C. polykomos exhibits traits that align more closely with putative leaping specializations when compared to P. badius (e.g., large femoral head, long femur, low femoral neck angle), while also possessing certain traits that are not (e.g., long femoral neck and reduced relative femoral robusticity). Consequently, C. polykomos likely experiences absolutely greater joint forces at the hip and higher bending at the femoral neck both when it leaps and bounds, given equivalent accelerations in bounding and leaping. Discussion: Bounding is best described as a form of low‐acceleration leaping. If bounding has lower acceleration requirements relative to leaping, C. polykomos achieves locomotor competence with less energy, relatively smaller bending moments, and reduced joint forces. [ABSTRACT FROM AUTHOR]

Objectives: Muscle activity during crouched walking has been previously studied in the context of the evolution of hominin bipedalism and human movement disorders. However, crouched walking could also be used in approach hunting where postural height (actual height of the body from the ground to the top of the head during locomotion) is the limiting factor. Here, we aim to analyze the relationship between relative postural height (%stature), kinematics, and muscle activity during crouched walking. Materials and Methods: Adult males (n = 19) walked with extended limbs and at three degrees of crouch while their 3D motion capture kinematics and lower limb muscle electromyography were recorded. We measured activation of tibialis anterior, soleus, gastrocnemius medialis, gastrocnemius lateralis, vastus lateralis, rectus femoris, biceps femoris, and gluteus maximus. We analyzed the effects of postural height on kinematics and muscle activation using linear mixed effects model. Results: Flexion angles, individual muscle activation (except for medial gastrocnemius), and total muscle activation were negatively related to relative postural height, that is, were greater at more crouched postures. Relative postural height had a stronger effect on the activation of the thigh and gluteal muscles compared to shank muscles. Discussion: General increase in lower limb muscle activation at lower postural heights suggests a negative relationship between relative postural height and fatigue, and may indicate a possible mechanism by which short stature could benefit the hunter in approach hunting. Greater activation of thigh and gluteal muscles relative to shank muscles may help to identify crouched walking in past human populations. [ABSTRACT FROM AUTHOR]

The foot is responsible for the bodyweight transfer to the ground, while adapting to different terrains and activities. Despite this fundamental role, the knowledge about the foot bone intrinsic kinematics is still limited. The aim of the study is to provide a quantitative and systematic description of the kinematics of all bones in the foot, considering the full range of dorsi/plantar flexion and pronation/supination of the foot, both in weightbearing and nonweightbearing conditions. Bone kinematics was accurately reconstructed for three specimens from a series of computed tomography scans taken in weightbearing configuration. The ground inclination was imposed through a set of wedges, varying the foot orientation both in the sagittal and coronal planes; the donor body‐weight was applied or removed by a cable‐rig. A total of 32 scans for each foot were acquired and segmented. Bone kinematics was expressed in terms of anatomical reference systems optimized for the foot kinematic description. Results agree with previous literature where available. However, our analysis reveals that bones such as calcaneus, navicular, intermediate cuneiform, fourth and fifth metatarsal move more during foot pronation than flexion. Weightbearing significantly increase the range of motion of almost all the bone. Cuneiform and metatarsal move more due to weightbearing than in response to ground inclination, showing their role in the load‐acceptance phase. The data here reported represent a step toward a deeper understanding of the foot behavior, that may help in the definition of better treatment and medical devices, as well as new biomechanical model of the foot. [ABSTRACT FROM AUTHOR]

Background: An increasing number of commercially available wearables provide real‐time feedback on running biomechanics with the aim to reduce injury risk or improve performance. Objective: Investigate whether real‐time feedback by wearable insoles (ARION) alters running biomechanics and improves running economy more as compared to unsupervised running training. We also explored the correlation between changes in running biomechanics and running economy. Methods: Forty recreational runners were randomized to an intervention and control group and performed ~6 months of in‐field training with or without wearable‐based real‐time feedback on running technique and speed. Running economy and running biomechanics were measured in lab conditions without feedback pre and post intervention at four speeds. Results: Twenty‐two individuals (13 control, 9 intervention) completed both tests. Both groups significantly reduced their energetic cost by an average of −6.1% and −7.7% for the control and intervention groups, respectively. The reduction in energy cost did not significantly differ between groups overall (−0.07 ± 0.14 J∙kg∙m−1, −1.5%, p = 0.63). There were significant changes in spatiotemporal metrics, but their magnitude was minor and did not differ between the groups. There were no significant changes in running kinematics within or between groups. However, alterations in running biomechanics beyond typical session‐to‐session variation were observed during some in‐field sessions for individuals that received real‐time feedback. Conclusion: Alterations in running biomechanics as observed during some in‐field sessions for individuals receiving wearable‐based real‐time feedback did not result in significant differences in running economy or running biomechanics when measured in controlled lab conditions without feedback. [ABSTRACT FROM AUTHOR]

Various sensory feedback methods are considered important for motor learning, but the effect of each sensory feedback method on effective squat learning still needs to be clarified. This study aimed to investigate the effect of sensory feedback types on the acquisition and retention of a squat. A double‐blinded, randomized controlled trial was carried out. Thirty‐healthy people were recruited and randomly assigned to the visual feedback group (VFG = 10), tactile feedback group (TFG = 10), and control group (CG = 10). VFG received visual feedback through video data of the participant performing squats, and TFG received tactile feedback through manual contact with a physical therapist. Both groups received feedback on the movements that needed correction after each set was completed. CG maintained rest without receiving any feedback. The retro‐reflexive marker, force plate, and electromyography were used to measure body angle, foot center of pressure (COP), and muscle activity. All assessments were measured to confirm a squat acquisition. VFG and TFG showed significant differences in neutral knee position (NKP), trunk forward lean (TFL), anterior knee displacement (AKD), and anteroposterior (AP) foot COP (p < 0.050). In addition, the acquisition was retained until 3 days later for NKP and a week later for TFL, AKD, and AP foot COP in VFG (p < 0.050), while the acquisition was not retained in TFG (p > 0.050). There was no statistically significant change in CG (p > 0.050). This study demonstrated that visual feedback positively affects the acquisition and retention of squats. Therefore, we recommend the use of visual feedback for squat acquisition and retention in exercise novices. [ABSTRACT FROM AUTHOR]

This study aimed to assess the acute effect of a competitive football match on jump performance and kinematic parameters during jump landing in semiprofessional female football players. Twenty‐two semiprofessional players (20 ± 3 years) underwent a drop jump task for a posterior video analysis of the landing phase. These measurements were obtained at (1) baseline, (2) after, and (3) 48 h after a competitive football match. A one‐way ANOVA with repeated measures was employed to detect differences over the time. There was a main effect of time for maximal knee flexion angle during drop landing (p = 0.001). In comparison with baseline, maximal knee flexion angle was reduced immediately post‐match and was still reduced 48 h after the match (63.4 ± 8.6 vs 57.0 ± 11.7 vs 48.9 ± 19.1, p ≤ 0.038). There was also a main effect of time for drop jump height (p < 0.001). Drop jump height was reduced immediately post‐match and remained low 48 h after the match in comparison with baseline (27.3 ± 3.6 vs 24.5 ± 2.8 ~ 25.5 ± 3.0 cm, p ≤ 0.002). There was a main effect of time on hip flexion angle during landing (p = 0.001), but the pairwise comparison revealed that this variable was not affected immediately post‐match but was lower 48 h after the match than at baseline (50.1 ± 10.1 ~ 50.8 ± 13.2 vs 38.1 ± 17.8 °, p ≤ 0.005). A competitive football match worsened jump performance and several landing biomechanical parameters in female football players, which were still decreased in comparison with baseline even 48 h after the match. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated the effects of a 12‐week gait retraining program on the morphological and mechanical properties of the Achilles tendon (AT) during running on the basis of real‐time dynamic ultrasound imaging. Methods: A total of 30 male recreational runners who were used to wearing cushioned shoes with a rearfoot strike (RFS) pattern were recruited. They were randomized into a retraining group (RG, n = 15) and a control group (CG, n = 15). The RG group was asked to run in five‐fingered minimalist shoes with a forefoot strike (FFS) pattern, and the CG group was asked to keep their strike pattern. Three training sessions were performed per week. All the participants in RG uploaded running tracks obtained through a mobile application (.jpg) after each session for training supervision. The ground reaction force, kinematics, and kinetics of the ankle joint at 10 km/h were collected using an instrumented split‐belt treadmill and a motion capture system. The morphological (length and cross‐sectional area) and mechanical characteristics (force, stress, strain, etc.) of AT in vivo were recorded and calculated with a synchronous ultrasonic imaging instrument before and after the intervention. Repeated two‐way ANOVA was used to compare the aforementioned parameters. Results: A total of 28 participants completed the training. The strike angle of RG after training was significantly smaller than that before training and significantly smaller than that of CG after training (F(1, 13) = 23.068, p < 0.001, partial η2 = 0.640). The length (F(1, 13) = 10.086, p = 0.007, partial η2 = 0.437) and CSA (F(1, 13) = 7.475, p = 0.017, partial η2 = 0.365) of AT in RG increased after training. A significant main effect for time was observed for the time‐to‐peak AT force (F(1, 13) = 5.225, p = 0.040, partial η2 = 0.287), average (F(1, 13) = 7.228, p = 0.019, partial η2 = 0.357), and peak AT loading rate (F(1, 13) = 11.687, p = 0.005, partial η2 = 0.473). Conclusion: Preliminary evidence indicated that a 12‐week gait retraining program could exert a beneficial effect on AT. 57% (8/14) runners in RG shifted from RFS to FFS pattern. Although not all runners were categorized as FFS pattern after the intervention, their foot strike angle was reduced. Retraining primarily positively promoted AT morphological properties (i.e., CSA and length) to strengthen AT capability for mechanical loading. [ABSTRACT FROM AUTHOR]

Purpose: Jump‐landing exercises are often performed during the rehabilitation of Achilles tendon (AT) injuries. However, the factors that affect the AT force (ATF) during landing are unclear. This study aimed to determine the kinematics and ground reaction force (GRF) variables associated with the peak ATF during a drop vertical jump (DVJ). Methods: The landing phase of DVJ was evaluated in 101 healthy participants (46 males, age: 21.2 ± 1.4 years old) using a three‐dimensional motion analysis system with two force plates. ATF was estimated from the ankle flexion angle and moment. Univariate and multivariate regression analyses were performed with the peak ATF as the dependent variable. The vertical GRF (VGRF), center of pressure (COP), forward trunk leaning, hip/knee/ankle joint angles at peak ATF, and sex were used as independent variables. Results: In the univariate regression analysis, larger VGRF (β = 0.813), more anterior COP position (β = 0.214), smaller knee flexion (β = −0.251) and adduction (β = −0.252), smaller hip flexion (β = −0.407), smaller forward trunk lean (β = −0.492), and male sex (β = −0.282) were significantly associated with a larger peak ATF. Multivariate analysis revealed that larger VGRF (β = 1.018), more anterior COP position (β = 0.320), a larger knee (β = 0.442), and smaller hip flexion (β = −0.205) were associated with the larger peak ATF. Conclusions: The VGRF, COP position, and knee and hip flexion were independently associated with ATF. Modifying these factors may be useful in managing tendon loading during jump‐landing exercises. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to examine whether 10‐20‐30 training (consecutive 1‐min intervals consisting of 30 s at low‐speed, 20 s at moderate‐speed, and 10 s at high‐speed), performed with submaximal effort during the 10‐s high‐speed runs, would lead to improved performance as well as increased maximum oxygen uptake (VO2‐max) and muscle oxidative phosphorylation (OXPHOS). In addition, to examine to what extent the effects would compare to 10‐20‐30 running conducted with maximal effort. Design: Nineteen males were randomly assigned to 10‐20‐30 running performed with either submaximal (SUBMAX; n = 11) or maximal (MAX; n = 8) effort, which was conducted three times/week for 6 weeks (intervention; INT). Before and after INT, subjects completed a 5‐km running test and a VO2‐max test, and a biopsy was obtained from m. vastus lateralis. Results: After compared to before INT, SUBMAX and MAX improved (p < 0.05) 5‐km performance by 3.0% (20.8 ± 0.4 (means±SE) vs. 21.5 ± 0.4 min) and 2.3% (21.2 ± 0.4 vs. 21.6 ± 0.4 min), respectively, and VO2‐max was ~7% higher (p < 0.01) in both SUBMAX (57.0 ± 1.3 vs. 53.5 ± 1.1 mL/min/kg) and MAX (57.8 ± 1.2 vs. 53.7 ± 0.9 mL/min/kg), with no difference in the changes between groups. In SUBMAX, muscle OXPHOS was unchanged, whereas in MAX, muscle OXPHOS subunits (I‐IV) and total OXPHOS (5.5 ± 0.3 vs 4.7 ± 0.3 A.U.) were 9%–29% higher (p < 0.05) after compared to before INT. Conclusion: Conducting 10‐20‐30 training with a non‐maximal effort during the 10‐s high‐speed runs is as efficient in improving 5‐km performance and VO2‐max as maximal effort exercise, whereas increase in muscle OXPHOS occur only when the 10‐s high‐speed runs are performed with maximal effort. [ABSTRACT FROM AUTHOR]

Purpose: Para‐alpine sit skiers face unique challenges in balance control due to their disabilities and the use of sit skis. This study assessed their multi‐joint coordination before and after slackline training. Methods: Nine alpine sit skiers (6 M/3 F; 27 ± 8 years; height: 168.3 ± 6.0 cm; body mass: 55.4 ± 6.9 kg) with different disabilities (LW10‐LW12) volunteered for the experiment. All subjects performed slackline training for 5 weeks (20 sessions). Joint kinematics were captured by vision‐based markerless motion analysis. Root mean square (RMS) amplitude, mean velocity and mean power frequency (MPF) were evaluated. Results: After training, performance improved significantly with an increase in balance time (1041%, p = 0.002), and a decrease in joint angular velocities and RMS amplitude of the sit ski foot (p < 0.05). Joint synergies were developed through in‐ or anti‐phase movements between joint pairs, particularly involving the hip joints (continuous relative phase angles ~0° or 180°, p < 0.001). Multi‐joint coordination shifted from large‐RMS amplitude of elbows to low‐MPF large‐RMS amplitude of the hip and shoulders (p < 0.05), with a significant increase of hip weighting (77.61%, p = 0.031) in the principal component analysis. The coordination was maintained with the change of slackline tension (p < 0.05). Athletes with severe trunk disabilities (LW10) had shorter balance time and poorer coordination than athletes with full trunk functions (LW12). Conclusions: Our findings showed the development of joint coordination involving better control of the hip and sit skis during the challenging slackline training task. [ABSTRACT FROM AUTHOR]

Ice hockey is an intense team sport characterized by repeated bursts of fast‐paced skating, rapid changes in speed and direction and frequent physical encounters. These are performed in on‐ice shifts of ~30–80 s interspersed with longer sequences of passive recovery, resulting in about 15–25 min on‐ice time per player. Nearly 50% of the distance is covered at high‐intensity skating speeds and with an accentuated intense activity pattern in forwards compared to defensemen. During ice hockey match‐play, both aerobic and anaerobic energy systems are significantly challenged, with the heart rate increasing toward maximum levels during each shift, and with great reliance on both glycolytic and phosphagen ATP provision. The high‐intensity activity pattern favors muscle glycogen as fuel, leading to pronounced reductions despite the relatively brief playing time, including severe depletion of a substantial proportion of individual fast‐ and slow‐twitch fibers. Player‐tracking suggests that the ability to perform high‐intensity skating is compromised in the final stages of a game, which is supported by post‐game reductions in repeated‐sprint ability. Muscle glycogen degradation, in particular in individual fibers, as well as potential dehydration and hyperthermia, may be prime candidates implicated in exacerbated fatigue during the final stages of a game, whereas multiple factors likely interact to impair exercise tolerance during each shift. This includes pronounced PCr degradation, with potential inadequate resynthesis in a proportion of fast‐twitch fibers in situations of repeated intense actions. Finally, the recovery pattern is inadequately described, but seems less long‐lasting than in other team sports. [ABSTRACT FROM AUTHOR]

A generalized model of flow of viscous thin film has been presented and the film is maintained over a porous, moving and non‐flat sheet. We categorically emphasized on the nonuniform and nonlinear kinematics of the sheet and deformation of thin film and variation of all quantities specified at the boundaries are taken of exponential type. The combined effects of deformation of both thin film and sheet along with the nonlinear kinematics of sheet have been analyzed on the characteristics of flow. The governing partial differential equations are transformed into ordinary differential equations (ODEs) by using similarity transformations and the final problem of ODEs is solved with the help of bvp4c technique, whereas, the result for the velocity and skin friction are graphed for different values of the injection (suction), stretching (shrinking) and deformation (contraction/expansion) of both thin film and sheet parameters. Note that the increasing, decreasing, uniform, linear, nonlinear and boundary layer behaviors of the velocity profiles and skin friction are noted for multiple choices of the parameters. Moreover, flows in upstream and downstream directions have been observed for different values and diverse nature of the parameters. [ABSTRACT FROM AUTHOR]

Research on infant and toddler reaching has shown evidence for motor planning after the initiation of the reaching action. However, the reach action sequence does not begin after the initiation of a reach but rather includes the initial visual fixations onto the target object occurring before the reach. We developed a paradigm that synchronizes head‐mounted eye‐tracking and motion capture to determine whether the latency between the first visual fixation on a target object and the first reaching movement toward the object predicts subsequent reaching behavior in toddlers. In a corpus of over one hundred reach sequences produced by 17 toddlers, we found that longer fixation‐reach latencies during the pre‐reach phase predicted slower reaches. If the slowness of an executed reach indicates reach difficulty, then the duration of pre‐reach planning would be correlated with reach difficulty. However, no relation was found with pre‐reach planning duration when reach difficulty was measured by usual factors and independent of reach duration. The findings raise important questions about the measurement of reach difficulty, models of motor control, and possible developmental changes in the relations between pre‐planning and continuously unfolding motor plans throughout an action sequence. [ABSTRACT FROM AUTHOR]

This paper presents a model‐free data‐driven strategy for linear and non‐linear finite element computations of open‐cell foam. Employing sets of material data, the data‐driven problem is formulated as the minimization of a distance function subjected to the physical constraints from the kinematics and the balance laws of the mechanical problem. The material data sets of the foam are deduced here from representative microscopic material volumes. These volume elements capture the stochastic characteristics of the open‐cell microstructure and the properties of the polyurethane material. Their computation provides the required stress‐strain data used in the macroscopic finite element computations without postulating a specific constitutive model. The paper shows how to derive suitable material data sets for the different cases of (non‐)linear and (an‐)isotropic material behavior efficiently. The numerical example of a rubber sealing illustrates possible areas of application, and the proposed strategy's versatility. [ABSTRACT FROM AUTHOR]

In the present contribution, the FE2 scheme for beam elements is extended to thermomechanically coupled problems. Beam elements have the advantage of drastically reducing the number of degrees of freedom compared to solid elements. However, the major challenge in modeling structures with beam elements lies in developing sophisticated non‐linear beam material models. This drawback resides in the fact that these elements require effective cross‐sectional properties involving material and geometric properties. The FE2 method, combined with a homogenization scheme based on the Hill‐Mandel condition, solves this problem. Within this scheme, homogenization of a representative volume element (RVE) on the mesoscopic scale provides effective cross‐sectional properties for the macroscopic scale. This homogenization procedure allows the consideration of non‐linear material formulations and cross‐sectional deformation within the analysis of a beam structure. The applicability of such a FE2 scheme for purely mechanical problems was already shown. In the present contribution, an extension to thermomechanically coupled problems is provided. In the proposed setting, the macroscopic scale is represented by beam elements with displacement, rotation, and temperature degrees of freedom. Solid elements with displacements and temperature degrees of freedom describe the behavior of the RVE. Hence, the proposed extension solves both scales in a monolithic approach. The assumption of a steady state problem at both scales allows a focus on a consistent scale transition and a discussion about the choice of suitable boundary conditions under the assumption of beam kinematics. [ABSTRACT FROM AUTHOR]

Introduction: Tibial stress injuries are a burdensome injury among military recruits. Military activities include running and the carriage of additional weight, and this may be related to the high risk of bone stress injuries. The aim of this study was to quantify tibial loading when running at two different speeds, with and without additional weight, and to quantify their combined influence. Methods: Fourteen male distance runners who ran at least 40 km per week ran barefoot on a force‐instrumented treadmill in four conditions representing preferred running speed (mean (SD) 3.1 (0.3) m/s) and 20% increased running speed (3.8 (0.4) m/s), with and without 20% of body weight carried in a weight vest. Kinematics and kinetics were synchronously collected. Bending moments were estimated about the medial‐lateral axis of the tibial centroid located 1/3rd of the length from distal to proximal. Static equilibrium was ensured at each 1% of stance. Peak bending moments were obtained in addition to cumulative‐weighted loading, where weighted loading accounted for the relative importance of the magnitude of the bending moment and the quantity of loading using a bone‐dependent weighting factor. Results: There were no interaction effects for running speed and weight carriage on peak or cumulative tibial loading. Running at a 20% faster speed increased peak and cumulative loading per kilometer by 8.0% (p < 0.001) and 4.8% (p < 0.001), respectively. Carriage of an additional 20% of body weight increased peak and cumulative loading per kilometer by 6.6% (p < 0.001) and 8.5% (p < 0.001), respectively. Interpretation: Increasing the physical demand of running by increasing speed or weight carriage increased peak tibial loading and cumulative tibial loading per kilometer, and this may increase the risk of tibial stress injury. Running speed and weight carriage independently influenced tibial loading. [ABSTRACT FROM AUTHOR]

Controlling a robot manipulator system with both uncertain kinematics and dynamics is a challenging problem since the traditional control schemes that relying on the robot system models are no longer applicable. Developing a neural network‐based adaptive tracking control for such uncertain robot manipulator systems with region constraints is especially changing. In this paper, region tracking controllers are designed for a robot manipulator systems with uncertain kinematics and dynamics. The developed region tracking controllers ensures that the uncertain robot manipulator can track a moving region other than the traditional fixed point, which has better redundancy characteristics. The results are obtained through the development of the sliding‐mode and a novel proportion‐integration‐differentiation (PID)‐like method to address the region tracking control problem. Numerical simulations are presented to verify the proposed controller's performance. [ABSTRACT FROM AUTHOR]

Punching failure of footings on a sand layer over clay: Calculation methods and insights from numerical parametric studies Punching failure of foundations on a layer of sand over clay is relevant for the bearing capacity of working platforms and the stability of footings. In practice, the analytical model according to Meyerhof and Hanna with a cuboid failure block in the sand layer has been used so far. The punching coefficient required for this is estimated from empirical diagrams that are partly of unclear origin. Various alternatives have been proposed in recent years, some using inclined sliding surfaces in the sand. An overview of these works is provided in the first part of this paper. These studies are extended herein by a detailed numerical parameter investigation. The finite element method is used to calculate the punching failure resistance in conjunction with an elastoplastic material model. The composite rigid body collapse mechanism method is used to identify the kinematics at failure. From a synthesis of the results, an analytical method for calculating the ultimate bearing stress of strip and rectangular footings is developed, which covers the range of values for the parameters encountered in practice. [ABSTRACT FROM AUTHOR]

Calculation of the punching failure resistance of foundations The phenomenon of punching failure of a foundation that stands on a bearing layer above a water‐saturated soft layer with minor bearing capacity is defined and described and the mechanics are explained. A calculation method is being developed for this problem. This is based on failure kinematics observed in model tests and a static assumption regarding the stress distribution in horizontal sections through the punched body, which is expressed by a ratio value. This static ratio value was determined for various surface load distributions using finite element calculations and given in a table. The calculation method is formulated as a slice method with horizontal slices and can be carried out in a simple manual calculation. Two real, well‐documented examples are calculated in detail and confirm the accuracy of the method. [ABSTRACT FROM AUTHOR]

Cable‐driven parallel robots (CDPRs) are parallel robots in which cables are used instead of rigid connecting elements. An important task here, as in other areas of robotics, are kinematic calculations. The state of the CDPR can be described either in Cartesian workspace coordinates as a pose or in the joint space via the cable lengths. The calculation of the cable lengths from a given platform pose is relatively simple for CDPRs. In contrast, the forward kinematics, that is, the calculation of the pose from the cable lengths, is complex due to the parallel topology and often cannot be solved analytically. In addition, CDPR systems are often designed redundantly, with more cables than Cartesian degrees of freedom. This redundancy causes that the solution of the forward kinematics can be considered as a fitting problem, where for measured cable lengths, the solution with minimum error norm is sought. In this paper, an approach based on the Gauss–Newton method is presented. It is described how a computationally efficient implementation is possible when using quaternions under consideration of the unit quaternion constraints. [ABSTRACT FROM AUTHOR]

High‐speed‐cutting) milling is an extensively used production process in tool‐making and mold‐making industries. For the purpose of a self‐balancing tool, a hollow shaft is used and filled partially with a fluid. This talk presents different beam and shell models for the investigation of nonlinear vibrations. Therefore, different theories are compared with respect to the influence of geometrical nonlinearities, spin‐softening as well as stress‐stiffening, and also shear deformation. Additionally, a stochastic Wedig–Dimentberg approach is presented for the simulation of a spatial distributed unbalance. Starting with the nonlinear kinematics for the tool‐deformation Hamilton's principle is evaluated for the variational formulation of each model. Regarding to the shear deformation, the theories of Euler–Bernoulli and Ehrenfest–Timoshenko (beam models) as well as Kirchhoff–Love and Mindlin–Reissner (shell models) are used. In the following up, the variational formulation is discretized under usage of a global Ritz approach on the one hand, and on the other hand with a local finite element (FE) discretization. Afterward, the governing system of differential equations is solved and discussed. Different results of rotating and nonrotating tools are presented, which show the available options of each theory and also their limits. In particular, results of the eigenfrequencies including their stochastic distribution, stationary deformation, stability behavior, and various time solutions are shown. [ABSTRACT FROM AUTHOR]

An increasing demand for paper and paperboard in engineering applications has emerged throughout the years. This leads to a growing interest in simulation tools to predict the material behavior, which is challenging due to the anisotropic structure of the material. It can be divided into in‐plane and out‐of‐plane behavior, which is mostly independent of each other resulting from the microstructure. Thus, a constitutive material model that captures in‐plane and out‐of‐plane behavior in a consistent manner is desired to simulate complex deformation states. The decoupling will be incorporated by a decomposition of the kinematics and the energy formulation into in‐plane and out‐of‐plane terms by use of structural tensors. This approach is flexible and can easily be extended to inelastic material behavior. In this work, the introduction of the decoupling into a constitutive material model for inelastic behavior is described. Visco‐elasticity is included through inelastic potentials. Three different potential formulations are given where focus is on the third, novel formulation, which defines inelastic strain evolution only in out‐of‐plane directions. The capabilities of this formulation are compared to the remaining potentials by simulations of a pinched cylinder that is loaded in the out‐of‐plane direction. [ABSTRACT FROM AUTHOR]

Biomechanical modeling and simulation is expected to play a significant role in the development of the next generation tools in many fields of medicine. However, full‐order finite element models of complex organs such as the heart can be computationally very expensive, thus limiting their practical usability. Therefore, reduced models are much valuable to be used, for example, for pre‐calibration of full‐order models, fast predictions, real‐time applications, and so forth. In this work, focused on the left ventricle, we develop a reduced model by defining reduced geometry & kinematics while keeping general motion and behavior laws, allowing to derive a reduced model where all variables & parameters have a strong physical meaning. More specifically, we propose a reduced ventricular model based on cylindrical geometry & kinematics, which allows to describe the myofiber orientation through the ventricular wall and to represent contraction patterns such as ventricular twist, two important features of ventricular mechanics. Our model is based on the original cylindrical model of Guccione, McCulloch, & Waldman (1991); Guccione, Waldman, & McCulloch (1993), albeit with multiple differences: we propose a fully dynamical formulation, integrated into an open‐loop lumped circulation model, and based on a material behavior that incorporates a fine description of contraction mechanisms; moreover, the issue of the cylinder closure has been completely reformulated; our numerical approach is novel aswell, with consistent spatial (finite element) and time discretizations. Finally, we analyze the sensitivity of the model response to various numerical and physical parameters, and study its physiological response. [ABSTRACT FROM AUTHOR]

Predator–prey interactions are ubiquitous and under strong selection because of the consequences experienced by both predator and prey if they lose the interaction. Biomechanics and behavior play important roles in the outcome of these interactions, but many studies focus on the prey, restrict the range of behaviors considered, and the role of prey boldness in the outcome is not understood. We used high‐speed video to test for effects of multiple measures of performance and kinematics of both the predator and prey, and boldness of prey on the outcome of interactions between Pike Cichlids (Crenicichla sp.) and Guppies (Poecilia reticulata). We found high variation in the behaviors employed during the predator–prey interactions, including in suction versus raptorial feeding, strike accuracy, and guppy responsiveness. We also found that predators moving relatively slower and prey moving relatively faster were more successful at consuming the prey and evading the predator, respectively. Prey that reacted farther from the predator was more likely to escape predation, but boldness of the prey did not affect the interaction. Our work suggests that a high level of variation in predator–prey interactions is widespread, even when strike and escape behaviors are stereotyped. We also showed that what both the predator and the prey do during an interaction are important in determining the outcome. [ABSTRACT FROM AUTHOR]

Background and Objective: Patellar tendinopathy (PT) is a highly prevalent overuse injury in volleyball and is often linked with overloading of the patellar tendon. Little is known, however, about whether and how patellar tendon loading is affected by fatigue during the most challenging jump activity in volleyball. Therefore, this study investigates the effect of a high‐intensity, intermittent fatigue protocol on movement alterations in terms of patellar tendon loading during a volleyball spike jump. Methods: Forty‐three male volleyball players participated in this study. Three‐dimensional full‐body kinematics and kinetics were collected when performing a spike jump before and after the fatigue protocol. Sagittal plane joint angles, joint work and patellar tendon loading were calculated and analyzed with curve analyses using paired sample t‐tests to investigate fatigue effects (p < 0.05). Results: Fatigue induced a stiffer lower extremity landing strategy together with prolonged pelvis‐trunk flexion compared to baseline (p = 0.001–0.005). Decreased patellar tendon forces (p = 0.001–0.010) and less eccentric knee joint work (−5%, p < 0.001) were observed after the fatigue protocol compared to baseline. Conclusion: Protective strategies seem to be utilized in a fatigued state to avoid additional tensile forces acting on the patellar tendon, including proximal compensations and stiff lower extremity landings. We hypothesize that players might be more prone for developing PT if eccentric patellar tendon loads are high in the non‐fatigued state and/or these loads are somehow not decreased after fatigue. [ABSTRACT FROM AUTHOR]

Multi-stable structures and metamaterials with more than two stable states are widely applied in diversified engineering applications. Non-rigid foldable origami patterns have provided an effective way of designing multi-stable structures. But most of them have only two stable states and therefore require a combination of many units to achieve multi-stability. Here, a series of extensible origami structures are proposed with generic multi-stability based on non-rigid wrapping origami. Through a kinematic analysis and experiments, it is demonstrate that a sequential folding among different layers of the structures is created to generate a continuous rigid origami range and several discrete rigid origami states, which consequently leads to the multi-stability of the extensible origami structures. Moreover, the effects of design parameters on the mechanical properties of the structures are investigated by numerical simulation, enabling properties programmability upon specific needs. This study thus paves a new pathway for the development of novel multi-stable origami structures. [ABSTRACT FROM AUTHOR]