Extent Of Movement Research Articles

Assessing Proprioception in an Older Population: Reliability of a Protocol Based on Active Movement Extent Discrimination

Proprioceptive ability - the sense of where body parts are located in space - is one of many factors thought to affect falls risk among the elderly. Active movement extent discrimination is an approach to measuring proprioception that is administered in an ecologically valid testing environment to better reflect the exercise of proprioceptive skills in daily life. The Active Movement Extent Discrimination Apparatus (AMEDA) was developed to objectively measure this proprioceptive discrimination. However, the current absolute identification testing protocol is cognitively demanding, and it yields results that are insufficiently reliable to assess performance at the individual level. The objectives of this pilot study were to test the reliability and feasibility of a proposed new AMEDA testing protocol and to explore how performance related to cognitive ability and any perceived dysfunction in the foot or ankle. We tested 42 participants (aged 19 - 94 years) three times on the ankle AMEDA using a newly developed protocol that asked participants to report whether a given angle of ankle inversion was shallower or deeper than the immediately preceding inversion. Participants also completed the Stroop test, as a measure of cognitive ability, and two validated questionnaires for identifying foot or ankle dysfunction (the Cumberland Ankle Instability Tool and the Foot and Ankle Ability Measure). The proportion of correct responses for the AMEDA test showed the expected sigmoid shape of the psychometric function as signal strength increased. The intraclass correlation coefficient measured over the three tests was 0.65 (95% confidence interval: 0.49 - 0.78), suggesting moderate reliability. We found a positive and statistically significant correlation between AMEDA performance and Stroop results but no relationship between the AMEDA score and questionnaire-measured foot or ankle dysfunction. This study confirmed that the alternative testing protocol was simple to administer and easily understood by participants.

Movement of sturgeons (Acipenser oxyrinchus oxyrinchusandA. fulvescens) in the St. Lawrence Estuary: A 35‐year tagging study

Movement of Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and lake sturgeon (A. fulvescens) in the St. Lawrence Estuary (Québec, Canada) are not fully understood. To assess the movement extent of both species, a mark–recapture study was conducted in collaboration with commercial fishermen operating in the St. Lawrence Estuary. Between 1981 and 2015, 3,367 Atlantic sturgeon (fork length 21.8–199.5 cm) and 3,180 lake sturgeon (fork length 17.8–190.8 cm) were tagged and released. Of these, 673 Atlantic sturgeon and 42 lake sturgeon were recaptured. The maximum distances traveled between capture and recapture locations were 1,307 km for Atlantic sturgeon (8 years after initial capture) and 252 km for lake sturgeon (less than 1 year after initial capture). Statistical analyses identified differences in the dispersal distance of both species as revealed by a first component characterized by individuals with short dispersal distances (98% and <35 km for Atlantic sturgeon; 58% and <1 km for lake sturgeon) and a second component characterized by individuals with longer dispersal distances (2% and >600 km for Atlantic sturgeon; 42% and >190 km for lake sturgeon). We suggest that the short dispersal distances detected in the vast majority of Atlantic sturgeon recaptures likely reflect strong site fidelity, highlighting the importance of the St. Lawrence Estuary as a preferred habitat for juveniles and subadults. Although recaptures were low for lake sturgeon because this species is only marginally targeted by commercial fishermen in the St. Lawrence Estuary, our results also showed that this species uses estuarine habitats and that half of the population seems to exhibit strong site fidelity (67% of individuals were recaptured within 2 km).

Contributions of implicit and explicit memories to sensorimotor adaptation of movement extent during goal-directed reaching

We examined how implicit and explicit memories contribute to sensorimotor adaptation of movement extent during goal-directed reaching. Twenty subjects grasped the handle of a horizontal planar robot that rendered spring-like resistance to movement. Subjects made rapid “out-and-back” reaches to capture a remembered visual target at the point of maximal reach extent. The robot’s resistance changed unpredictably between reaches, inducing target capture errors that subjects attempted to correct from one trial to the next. Each subject performed over 400 goal-directed reaching trials. Some trials were performed without concurrent visual cursor feedback of hand motion. Some trials required self-assessment of performance between trials, whereby subjects reported peak reach extent on the most recent trial. This was done by either moving a cursor on a horizontal display (visual self-assessment), or by moving the robot’s handle back to the recalled location (proprioceptive self-assessment). Control condition trials performed either without or with concurrent visual cursor feedback of hand motion did not require self-assessments. We used step-wise linear regression analyses to quantify the extent to which prior reach errors and explicit memories of reach extent contribute to subsequent reach performance. Consistent with prior reports, providing concurrent visual feedback of hand motion increased reach accuracy and reduced the impact of past performance errors on future performance, relative to the corresponding no-vision control condition. By contrast, we found no impact of interposed self-assessment on subsequent reach performance or on how prior target capture errors influence subsequent reach performance. Self-assessments were biased toward the remembered target location and they spanned a compressed range of values relative to actual reach extents, demonstrating that declarative memories of reach performance systematically differed from actual performances. We found that multilinear regression could best account for observed data variability when the regression model included only implicit memories of prior reach performance; including explicit memories (self-assessments) in the model did not improve its predictive accuracy. We conclude therefore that explicit memories of prior reach performance do not contribute to implicit sensorimotor adaptation of movement extent during goal-directed reaching under conditions of environmental uncertainty.

Future Challenges in the Assessment of Proprioception in Exercise Sciences: Is Imitation an Alternative?

Future Challenges in the Assessment of Proprioception in Exercise Sciences: Is Imitation an Alternative?

PRICE VARIATION AND MOVEMENT OF Halea ciliata SPECIES OF LUMBER IN DELTA STATE, NIGERIA

The study examined the intensity of price movement and trend analysis of selected volumes (0.013m3, 0.019m3 and 0.025m3) of Halea ciliata in urban and local lumber markets in Delta State of Nigeria. Monthly sales records of Halea ciliata species of lumber (2010-2019) were taken from sales receipt and were analyzed using econometric analysis. Results showed that prices of Halea ciliata species of lumber and the volumes considered were non-stationery in their level forms but were stationary at first difference (P≤0.01 and P≤0.05). The indices of market concentration were less than one suggesting elevated level of short run market integration. Co-integration test showed that a long run stable relation exist between prices in local and urban markets while the Error correction mechanism reflect that the extent of price movement is relatively fast. The study concluded that lumber market for Halea ciliata is integrated and operated efficiently. It was recommended that intensive forest restoration be embarked upon for continuous supply of lumber to sellers.

Hangman's fracture: a clinical review based on surgical treatment of 15 cases.

This is a retrospective analysis of cases with hangman's fracture. The subject of 'hangman's fracture' has been elaborately evaluated in the literature. The authors propose an alternative format of surgical treatment that is based on modification of existing classification schemes. During the period 2015 to March 2020, 15 patients having hangman's fracture were identified and were surgically treated. The clinical condition was classified on the basis of American Spinal Injury Association scale (ASIA scale) and VAS parameters. The patients were classified into 4 groups depending on the presence (or absence) of atlantoaxial and/or C2-3 instability. Surgical decisions were guided by the proposed classification. Clinical evaluation and dynamic CT scan were done at follow-up visits. During the average follow-up of 26months, all patients are essentially asymptomatic. There was marginal restriction of extent of neck movements in all cases. There was solid bone fusion in all cases. The proposed novel classification scheme based on the presence of atlantoaxial and C2-3 instability assisted in directing the treatment strategy of hangman's fracture.

Instrumental Study of the Health Status of Picea abies [L.] Karst and Pinus mugo (Turra) and Their Relation to Environmental Parameters in the Eastern Alps

Many climatic models predict significant temperature rises in mountainous regions, which may influence the distribution of montane species. Thermophilization observed or predicted in mountainous areas to date may accelerate the shift of forest-forming trees to higher areas. Our aim was to detect how the health status of Norway spruce (Picea abies [L.] Karst) and dwarf mountain pine (Pinus mugo (Turra)) changes along an altitudinal transect, and to what extent the health status of trees depends on the studied environmental variables. Field measurements were performed in the Alps with an acoustic tomograph, which is able to determine the extent and exact location of rotten parts without damage. In the case of P. abies, the stands are currently considered to be the healthiest between 1000 and 1500 m, while they show the greatest deterioration near the lower limit of their distribution. At the lower limit of the vertical distribution of the species, a retreat of 50–100 m is expected. We observed a different trend in the relationship between deterioration values and altitude depending on the extent of the P. mugo belt. It seems the extent and speed of the upper movement may be different in different mountains, depending on environmental parameters.

Inferring Movements and Staging Locations for Canvasbacks Using Light-Level Geolocators

Abstract Understanding the geographic extent and timing of wildlife movements enables resource managers to inform habitat needs of target species efficiently and effectively. We use light-level geolocators—which enable researchers to estimate individual locations from light-level data—to build a more complete understanding of the geography and timing of migratory movements for canvasback Aythya valisineria in the Pacific Flyway. During the springs of 2015–2017, we placed 151 geolocators on canvasbacks using two alternative attachment methods (leg-band vs. nasal-saddle mounts) during spring migration (February–March) near Reno, Nevada. Eight of these geolocators (five males and three females) were successfully retrieved, representing 10 near-complete annual migration cycles (two geolocators contained data for two migration years). Eight of the 10 estimated spring canvasback migrations (five male and three female) ended at breeding sites in the Prairie Pothole Region of southern Canada and northern United States (often via stopover sites in Utah and Montana), whereas one male and one female migrated to breeding sites in Alaska. Notably, one female settled on nesting grounds in southern Saskatchewan and then in central Alaska in successive years. During spring migration, canvasbacks made an average of 3.3 ± 0.5 stopovers, with an average duration of 14.8 ± 2.2 d. Three canvasbacks made a distinct molt migration after breeding. For fall migration, canvasback made an average of 2.7 ± 0.3 stopovers, lasting an average of 12.3 ± 2.5 d, on their way to wintering sites in California's Central Valley and coastal regions near San Francisco Bay. Retrieval rate for nasal-saddle-mounted geolocators was significantly lower than leg band-mounted devices because of failure of nasal-saddle attachment. This study demonstrates the value of geolocators for assessing year-round habitat use for waterfowl species that have negative behavioral reactions to traditional backpack devices. This information complements standard band-recovery approaches and enables waterfowl managers to ensure that the spatial and temporal distributions of individuals are identified so that habitat conservation efforts can reflect the full annual habitat use cycle.

A prospective cohort study evaluating subjective and objective neurosensory changes following LeFort I osteotomy

This study aimed to investigate the incidence and recovery of neurosensory deficit (NSD) after LeFort I osteotomy over 12months and identify any association between age, gender, and extent of surgical movement on recovery. Furthermore, the study explored the relationship between objective and subjective outcome measures. A prospective cohort study consisting of 31 patients. Subjects were assessed at baseline, 1week (T1), 1month, 3months, 6months, and 12months (T5) after LeFort I osteotomy. Objective assessment measures included pinprick (PP), static light touch (SLT), static 2-point discrimination (STPD), and electric pulp testing (EPT). Subjective reporting was undertaken using a visual analog scale. Patients rated the impact of NSD on intraoral and extraoral sites at the same time points as for objective measures. Twenty-eight patients (16 females and 12 males) with a mean age of 24.5years (standard deviation, 7.4) completed the study. There was a notable reduction in NSD from T1 (85.7%) to T5 (17.9%). No significant differences were found with respect to the influence of gender; PP (P=0.06), SLT (P=0.10), STPD (P=0.65) and EPT (P=0.19) or extent of surgical movement; PP (P=0.50), SLT (P=0.72), STPD (P=0.06) and EPT (P=0.74) on NSD. Age is a significant factor for intraoral NSD in the immediate postoperative period; PP (P<0.0001) and SLT (P<0.0001). Subjectively, patients reported a high degree of concern associated with NSD immediately after surgery with a gradual reduction from T1 to T5. There is a significant difference in subjective reporting between those with intraoral NSD than those with no intraoral NSD at 12months (P=0.031). NSD is high after LeFort I surgery, particularly intraorally in the palate. At 12months, the incidence of NSD is 17.9%. Recovery of NSD to a nonsignificant value from baseline takes up to 3months for extraoral sites and between 3 and 6months for intraoral soft tissues. The maxillary dentition continues to recover from NSD up to 12months postsurgery. Age, gender, and extent of the surgical movement do not influence the extent of NSD at 12months. Increasing age is associated with increased NSD at intraoral sites immediately after surgery. Intraoral NSD is more of a concern to patients than extraoral NSD. Patients' concerns associated with NSD reduced over time, demonstrating a degree of adaptation in the longer term.

Self-reported chronic ankle instability effects on the development of fitness during an Infantry Commanders Course

ObjectivesTo determine whether self-reported chronic ankle instability (CAI) affects the physical performance of soldiers during army training, in routine army fitness tests and other sensorimotor tests. DesignProspective cohort comparison. MethodsSoldiers enrolled on the Infantry Commanders Course (ICCourse) of the Israeli Defense Force were tested in weeks one and fourteen of the course, including a 3000 m timed run, an agility test over an X-shaped course, the Y Balance Test (YBT) and the Active Movement Extent Discrimination Assessment (AMEDA) somatosensory test. Soldiers were trained using routine ICCourse physical training throughout the course. Changes in physical performance were analysed using a two-way ANOVA, for soldier groups categorised as having healthy ankles or CAI. ResultsSoldiers improved their scores on all 4 tests (3000 m run, X-agility test, YBT and AMEDA) during the course. However, soldiers with CAI did not improve on the X-agility test, whilst those with healthy ankles did. Soldiers with CAI performed worse on the YBT-PM (postero-medial direction) at the start of the course, but this difference was no longer present at 14 weeks. Soldiers with CAI performed better on the AMEDA at the start and 14-week testing points. ConclusionsSelf-reported CAI restricts agility performance gains in soldiers during 14-weeks of physical training but has no effect on 3000 m running performance. Soldiers with CAI perform worse in YBT balance tests. Soldiers with CAI have better proprioceptive acuity than those with stable ankles. These findings indicate possible sensorimotor factors for training of soldiers with known CAI.

Tropism of Sub-Axial Cervical Facet Joints Is Not Related to Segmental Movement during Active Movement or Therapist-Perceived Symptomatic Locations

Tropism, or asymmetry, of facet joints in the cervical spine has been found to be related to degenerative changes of the joints and discs. Clinicians often assume that differences in segmental mobility are related to tropism. The aims of this study were to determine the relationship between asymmetry of facet joints in the sub-axial cervical spine and (1) segmental mobility and (2) spinal levels perceived by therapists to have limited mobility. Eighteen participants with idiopathic neck pain had MRIs of their cervical spine in neutral and at the end of active rotation. Angular movement and translational movement of each motion segment was calculated from 3D segmentations of the vertebrae. A plane was fitted to the facet on each side. Tropism was considered to be the difference in the orientation of the facet planes and ranged from 1 to 30° with a median of 7.7°. No relationships were found between the extent of tropism and either segmental movement or locations deemed to be symptomatic. Tropism in the sub-axial cervical spine does not appear to be related to segmental mobility in rotation or to levels deemed to be symptomatic.

Quantifying age-related differences in selective voluntary motor control in children and adolescents with three assessments.

Neurophysiological development of selective voluntary motor control (SVMC) is assumed but has not been quantified objectively. We assessed SVMC with (i) clinical assessments, (ii) a combination of these assessments with surface electromyography (sEMG) and, (iii) a playful computer game. The aim of this study was to describe and compare age-related differences in SVMC, quantified with these tools, in neurologically intact children, adolescents, and adults. We measured upper and lower extremity SVMC with three assessments in 31 children and adolescents. A sample of 33 and 31 adults provided reference values for the upper and lower extremity assessments, respectively. The Selective Control of the Upper Extremity Scale (SCUES) or the Selective Control Assessment of the Lower Extremity (SCALE) were combined with simultaneous sEMG recordings. We quantified SVMC by a similarity index that compared an individual's muscle activation pattern with those of an adult reference group. The SVMC Assessgame required isolated joint movements to steer an avatar and quantified the accuracy of the selective movement and the extent of involuntary movements occurring in not involved joints. Results from the conventional clinical assessments correlated low to moderately with age (SCUES: r=0.55, p=0.013; SCALE: r=0.44, p=0.001), while the correlation between the sEMG based similarity index and age was negligible (r≤0.25). The outcomes of the Assessgame correlated highly with age (r≥0.80, p≤0.001). Older children and adolescents performed movements more accurately and with fewer involuntary movements compared to younger participants. The tools assess and quantify SVMC differently, affecting the way they capture age-related differences in SVMC. Some assessments require reference values from neurologically intact children and adolescents to correctly classify impairments of SVMC in patients with neuromotor disorders.

Native Burmese pythons exhibit site fidelity and preference for aquatic habitats in an agricultural mosaic

Animal movement and resource use are tightly linked. Investigating these links to understand how animals use space and select habitats is especially relevant in areas affected by habitat fragmentation and agricultural conversion. We set out to explore the space use and habitat selection of Burmese pythons (Python bivittatus) in a heterogenous, agricultural landscape within the Sakaerat Biosphere Reserve, northeast Thailand. We used VHF telemetry to record the daily locations of seven Burmese pythons and created dynamic Brownian Bridge Movement Models to produce occurrence distributions and model movement extent and temporal patterns. To explore relationships between movement and habitat selection we used integrated step selection functions at both the individual and population level. Burmese pythons had a mean 99% occurrence distribution contour of 98.97 ha (range 9.05–285.56 ha). Furthermore, our results indicated that Burmese pythons had low mean individual motion variance, indicating infrequent moves and long periods at a single location. In general, Burmese pythons restricted movement and selected aquatic habitats but did not avoid potentially dangerous land use types like human settlements. Although our sample is small, we suggest that Burmese pythons are capitalizing on human disturbed landscapes.

How flexible are habitat specialists? Short-term space use in obligate coral-dwelling damselfishes

As habitats change, highly specialised species may die or be forced to relocate. However, some obligate coral-dwelling damselfishes appear to survive the localized extinction of their primary habitat, branching coral, caused by coral bleaching. To address this apparent paradox, we documented the spatial behaviour of obligate coral-dwellers in relation to habitat quality. Focussing on two obligate coral-dwelling damselfishes (Pomacentrus moluccensis and Chromis viridis), we used KUDs (Kernel Utilisation Distributions) to quantify fishes’ short-term space use (daily 5 min observations across 6 days) and related it to live coral cover and structural complexity derived from 3D photogrammetry. Specifically, we calculated movement extent (95% KUD), core areas (50% KUD) and the temporal consistency of occupied areas across consecutive days. Structural complexity had no effect on space use. The effect of live coral cover was significant but weak and dependent on fish body-size: core areas increased with decreasing live coral cover for large fishes; smaller fishes showed little response. In contrast to weak habitat effects, there were strong differences across sites. At one site, average core areas increased three-fold to 1.1 m2 for P. moluccensis and over 60-fold for C. viridis, from 1.14 m2 to an average core area of 92.34 m2 and a maximum recorded extent of 1471.4 m2. These findings may help explain these fishes’ apparent, unexpected resilience to habitat loss. Obligate coral-dwelling fishes may prefer branching live coral, but their ‘obligate’ dependence may be more flexible and context dependent. As ecosystems reconfigure, plasticity in fine-scale spatial behaviour may be critical for the persistence of fish populations.

Are the unreamed nails indicated in diaphyseal fractures of the lower extremity? A biomechanical study

IntroductionIntramedullary nailing is generally accepted as the first choice for the treatment of diaphyseal fractures of femur and tibia, with a gradual incease in the use of unreamed nails. Different studies during last years show controversial outcomes. Some authors strongly favor unreamed nailing, but most of the authors conclude that reamed nailing have proved to be more successful. Material and methodsThis study simulates unreamed intramedullary nailing of four femoral and three tibial fracture types by means of Finite Element (FE) models, at early postoperative stages with a fraction of physiological loads, in order to determine whether sufficient stability is achieved, and if the extent of movements and strains at the fracture site may preclude proper consolidation. ResultsThe behavior observed in the different fracture models is very diverse. In the new biomechanical situation, loads are only transmitted through the intramedullary nail. Mean relative displacement values of fractures in the femoral bone range from 0.30 mm to 0.82 mm, depending on the fracture type. Mean relative displacement values of the tibial fractures lie between 0.18 and 0.62 mm, depending on the type of fracture. Concerning mean strains, for femoral fractures the maximum strains ranged between 12.7% and 42.3%. For tibial fractures the maximum strains ranged between 10.9% and 40.8%. ConclusionsThe results showed that unreamed nailing provides a very limited mechanical stability, taking into account that analyzed fracture patterns correspond to simple fracture without comminution. Therefore, unreamed nailing is not a correct indication in femoral fractures and should be an exceptional indication in open tibial fractures produced by high-energy mechanism.

Radiologist Mouse Movements at a PACS Workstation.

HomeRadiologyVol. 299, No. 1 PreviousNext Reviews and CommentaryFree AccessImages in RadiologyRadiologist Mouse Movements at a PACS WorkstationJan Vosshenrich , Hanns-Christian BreitJan Vosshenrich , Hanns-Christian BreitAuthor AffiliationsFrom the Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland.Address correspondence to J.V. (e-mail: [email protected]).Jan Vosshenrich Hanns-Christian BreitPublished Online:Feb 16 2021https://doi.org/10.1148/radiol.2021203469MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In AbstractDownload as PowerPointBecause of the rising volumes and complexity of diagnostic imaging studies and the demand for advanced postprocessing, radiologists’ workloads continue to increase substantially. To reveal the extent of computer mouse movements, we tracked the activity of a radiology resident during an 8-hour shift. The figure shows the mouse movements (line coloration indicates movement orientation: vertical [pink], horizontal [green], and oblique [orange and purple]) and mouse stops (colored circles) at a typical radiology information system (RIS) and picture archiving and communication system (PACS) workstation set-up (one RIS monitor [Figure, part a] and two PACS monitors [Figure, part b]), tracked with software (version 1.0.1; IOGraph). The mouse activity added up to a distance of 2.2 km (1.37 miles) and 10 778 keystrokes (23 keystrokes per minute).(a) Mouse movements and mouse stops on radiology information system screen tracked over course of 8-hour shift. (b) Mouse movements and mouse stops on picture archiving and communication system screens tracked over course of 8-hour shift.Download as PowerPointOpen in Image Viewer (a) Mouse movements and mouse stops on radiology information system screen tracked over course of 8-hour shift. (b) Mouse movements and mouse stops on picture archiving and communication system screens tracked over course of 8-hour shift.Download as PowerPointOpen in Image Viewer The complex and extensive mouse patterns suggest the need for advanced user interface devices with greater functionality. Artificial intelligence solutions may also help automate time-consuming repetitive tasks (eg, creating hanging protocols or synchronizing image stacks). Optimization and streamlining these processes would be important for radiologists to keep pace with their increasing workloads.Disclosures of Conflicts of Interest: J.V. disclosed no relevant relationships. H.C.B. disclosed no relevant relationships.Article HistoryReceived: Aug 18 2020Revision requested: Aug 20 2020Revision received: Aug 21 2020Accepted: Aug 26 2020Published online: Feb 16 2021Published in print: Apr 2021 FiguresReferencesRelatedDetailsCited By2021 Top Images in Radiology: Radiology In Training Editors’ ChoicesFrancis Deng, Eric Kim, Anna V. Trofimova, Susanna I. Lee, 30 November 2021 | Radiology, Vol. 302, No. 3European Journal of Radiology, Vol. 155Recommended Articles 2021 Top Images in Radiology: Radiology In Training Editors’ ChoicesRadiology2021Volume: 302Issue: 3pp. 507-510Reducing Functional MR Imaging Acquisition Times by Optimizing WorkflowRadioGraphics2017Volume: 37Issue: 1pp. 316-322Translabial US and Dynamic MR Imaging of the Pelvic Floor: Normal Anatomy and DysfunctionRadioGraphics2018Volume: 38Issue: 1pp. 287-308Extraprostatic Tumor Extension: Comparison of Preoperative Multiparametric MRI Criteria and Histopathologic Correlation after Radical ProstatectomyRadiology2020Volume: 296Issue: 1pp. 87-95Increasing Median Time between Interruptions in a Busy Reading RoomRadioGraphics2021Volume: 41Issue: 2pp. E47-E56See More RSNA Education Exhibits Robotic Process Automation: Go Beyond Artificial Intelligence in the Radiology DepartmentDigital Posters2018Learning from Gamers: Multi-Button Mouse, Keypad and AHK Scripts as Tools to Simplify Complex Repetitive Tasks to Improve and Personalize WorkflowDigital Posters2018The On-Call Radiology Residents Guide to Managing the Reading Room: Distractions, Downtimes, and DiscussionsDigital Posters2019 RSNA Case Collection Primary gastric torsionRSNA Case Collection2021Hypertrophic Olivary DegenerationRSNA Case Collection2021Bucket handle tearRSNA Case Collection2020 Tweetorial » Vol. 299, No. 1 Metrics Altmetric Score PDF download

Alveolar cortical plate changes associated with incisor retraction and its influence on the limits of orthodontic tooth movement.

The extent to which the modelling behaviour of the anterior alveolus limits tooth movement remains unclear. Will the labial and lingual cortical plates model as incisors retract, or will they remain unchanged, therefore limiting the extent of possible tooth movement? Pre- and post-treatment lateral cephalometric radiographs of 29 bimaxillary protrusive patients of South Korean descent were examined. Treatment consisted of two premolar extractions in one or both arches with en masse retraction of the incisors using miniscrew anchorage. Pre- and post-treatment measurements of both tooth and cortical plate position were made at various increments along the length of the root and then compared using paired t tests. Despite the use of miniscrew anchorage, the incisors were retracted by controlled tipping. The labial cortical plates in both arches modelled to follow tooth movement. Following retraction of the incisors in the maxilla, the incisor root approached the lingual cortical plate, which remained unchanged. In the mandible, the lingual cortical plate position was unchanged except at the level closest to the cementoenamel junction. The maxillary and mandibular lingual cortical plates did not model to follow the incisor movement while the labial cortical plates did. These findings suggest that lingual cortical plates may act as limitations to planned orthodontic tooth movement.

Atypical Head Movement during Face-to-Face Interaction in Children with Autism Spectrum Disorder.

The present study implemented an objective head pose tracking technique-OpenFace 2.0 to quantify the three dimensional head movement. Children with autism spectrum disorder (ASD) and typical development (TD) were engaged in a structured conversation with an interlocutress while wearing an eye tracker. We computed the head movement stereotypy with multiscale entropy analysis. In addition, the head rotation range (RR) and the amount of rotation per minute (ARPM) were calculated to quantify the extent of head movement. Results demonstrated that the ASD group had significantly higher level of movement stereotypy, RR and ARPM in all the three directions of head movement. Further analyses revealed that the extent of head movement could be significantly explained by movement stereotypy, but not by the amount of visual fixation to the interlocutress. These results demonstrated the atypical head movement dynamics in children with ASD during live interaction. It is proposed that head movement might potentially provide novel objective biomarkers of ASD. LAY SUMMARY: Our study used an objective tool to quantify head movement in children with autism. Results showed that children with autism had more stereotyped and greater head movement. We suggest that head movement tracking technique be widely used in autism research.

Proprioceptive accuracy after uni-joint and multi-joint patterns of arm-raising movements directed to overhead targets

Aim To determine the effect of arm-raising pattern on upper limb proprioceptive accuracy for movements made to overhead targets. Materials and methods Sixteen healthy young adults were tested in standing with arms at the sides, made dominant arm-raising movements to an unseen overhead stop, randomly placed at one of five different overhead targets. Movements were made either as a uni-joint shoulder flexion movement in an arc, or as an unconstrained arm raising that was a series of multi-joint movements involving the shoulder, elbow, and wrist. Results Overall proprioceptive accuracy for discrimination between the five unseen overhead targets was not different after arm-raising with either a uni-joint or mult-joint pattern (F 1, 15 = 0.50, p = 0.49, partial η 2 = 0.03). Better performers with one pattern also tended to perform well with the other (r = 0.70, p = 0.003). Trend analysis across the 4 pairwise scores for discriminations between the target positions (171.8°–173.6°, 173.6°–175.4°, 175.4°–177.2°, and 177.2°–179.0°) showed worsening discrimination towards the more distant targets (F 1, 15 = 8.44, p = 0.01, partial η 2 = 0.36). However, this linear trend of falling discrimination accuracy was not different between the two movement patterns (p = 0.27). Conclusion Proprioceptive accuracy did not differ between simple uni-joint and more complex multi-joint arm-raising movement patterns, and the further the extent of the overhead target movement, the worse proprioceptive discrimination sensitivity for both movement patterns. Upper limb proprioceptive accuracy was therefore movement extent dependent, but movement pattern independent.

Controlling mine pressure by subjecting high-level hard rock strata to ground fracturing

When mining extra-thick coal seams, the main cause of strong ground pressure are the high-level thick and hard strata, but as yet there is no active and effective control technology. This paper proposes the method of subjecting hard roofs to ground fracturing, and physical simulation is used to study the control effect of ground fracturing on the strata structure and energy release. The results show that ground fracturing changes the structural characteristics of the strata and reduces the energy release intensity and the spatial extent of overburden movement, thereby exerting significant control on the ground pressure. The Datong mining area in China is selected as the engineering background. An engineering test was conducted on site by ground horizontal well fracturing, and a 20-m-thick hard rock layer located 110 m vertically above the coal seam was targeted as the fracturing layer. On-site microseismic monitoring shows that the crack propagation length is up to 216 m and the height is up to 50 m. On-site mine pressure monitoring shows that (1) the roadway deformation is reduced to 100 mm, (2) the periodic weighting characteristics of the hydraulic supports are not obvious, and (3) the ground pressure in the working face is controlled significantly, thereby showing that the ground fracturing is successful. Ground fracturing changed the breaking characteristics of the high-level hard strata, thereby helping to ameliorate the stress concentration in the stope and providing an effective control approach for hard rock.