Identifying consistent biomechanical parameters across rising-to-walk subtasks to inform rehabilitation in practice: A systematic literature review

© 2020 Elsevier B.V. Background: :The best approach to rehabilitate the control of everyday whole-body movement (e.g. rise-to-walk) after pathology remains unclear in part because the associated controlled performance variables are not known. Rise-to-walk can be performed fluidly (sit-to-walk) or non-fluidly (sit-to-stand, proceeded by gait-initiation). Biomechanical variables that remain consistent in health regardless of how rise-to walk is performed represent controlled performance variable candidates which could monitor rehabilitative change. Research Question: :To determine if any biomechanical parameters remain consistent across rising-to-walk (RTW) subtasks (sit-to-stand, gait-initiation, and sit-to-walk) in healthy adults for purposes of movement control assessment in clinical practice. Methods: :Data sources included Medline, Cinahl, and Scopus databases, and the grey literature. Study selection was based on eligibility criteria and must have reported spatiotemporal, kinematic and/or kinetic biomechanical parameters featuring >1 RTW subtask. Data extraction and synthesis; standardised-mean-differences (SMDs) were calculated (pooled if replicated in >1 study) for each parameter. Consistency was determined if SMD95 %CIs included the zero-effect line. Results: :Nine studies (n = 99) were included (40 ± 7.5yrs). Seven parameters were replicated in >1 study and subjected to meta-analysis (fixed-effect model). Two were consistent between sit-to-stand and sit-to-walk: flexion-momentum time (M(95 %CI) = 0.055(-0.423 to 0.533); p = 0.823) and peak whole-body-centre-of-mass vertical velocity (M(95 %CI)= -0.415(-0.898 to 0.069); p = 0.093); and centre-of-pressure to whole-body-centre-of-mass distance at toe-off (M(95 %CI)= -0.137(-0.712 to 0.439); p = 0.642) between gait-initiation and sit-to-walk. Another 20 parameters were consistent based on single-study SMDs. Significance: :Consistent parameters might exist across RTW subtasks. However, the evidence is based on few studies with small samples and variable RTW protocols. Future studies designed to confirm consistency using a standardised RTW protocol are needed

Comparison of human uterine cervical electrical impedance measurements derived using two tetrapolar probes of different sizes

BACKGROUND We sought to compare uterine cervical electrical impedance spectroscopy measurements employing two probes of different sizes, and to employ a finite element model to predict and compare the fraction of electrical current derived from subepithelial stromal tissue. METHODS Cervical impedance was measured in 12 subjects during early pregnancy using 2 different sizes of the probes on each subject. RESULTS Mean cervical resistivity was significantly higher (5.4 vs. 2.8 Ωm; p < 0.001) with the smaller probe in the frequency rage of 4–819 kHz. There was no difference in the short-term intra-observer variability between the two probes. The cervical impedance measurements derived in vivo followed the pattern predicted by the finite element model. CONCLUSION Inter-electrode distance on the probes for measuring cervical impedance influences the tissue resistivity values obtained. Determining the appropriate probe size is necessary when conducting clinical studies of resistivity of the cervix and other human tissues

Discovery of a transient radiation belt at Saturn

Radiation belts have been detected in situ at five planets. Only at Earth however has any variability in their intensity been heretofore observed, in indirect response to solar eruptions and high altitude nuclear explosions. The Cassini spacecraft's MIMI/LEMMS instrument has now detected systematic radiation belt variability elsewhere. We report three sudden increases in energetic ion intensity around Saturn, in the vicinity of the moons Dione and Tethys, each lasting for several weeks, in response to interplanetary events caused by solar eruptions. However, the intensifications, which could create temporary satellite atmospheres at the aforementioned moons, were sharply restricted outside the orbit of Tethys. Unlike Earth, Saturn has almost unchanging inner ion radiation belts: due to Saturn's near-symmetrical magnetic field, Tethys and Dione inhibit inward radial transport of energetic ions, shielding the planet's main, inner radiation belt from solar wind influences

Bioglass and bioactive glasses and their impact on healthcare

Glass caused a revolution in healthcare when Bioglass was discovered by Larry Hench. It was the first material to bond with bone, rather than be encapsulated by fibrous tissue, launching the field of bioactive ceramics . Bioglass is also biodegradable. Almost 50 years on from its discovery that revolution continues. Bioactive glasses stimulate more bone regeneration than other bioactive ceramics , which is attributed to their dissolution products stimulating cells at the genetic level. This second discovery has changed the way clinicians, scientists and regulatory bodies think about medical devices and the concept of bioactivity. The original 45S5 Bioglass has only re cently found really widespread use in orthop a edics, having regenerated the bones of more than 1.5 million patients. Its full potential is still yet to be fulfilled. Th is article takes the reader from Hench’s Bioglass 45S5 to its clinical uses and products, before giving examples of non - surgical products that now use Bioglass, from consumer products , such as toothpaste, to cosmetics . Other glasses have also found important healthcare applications, such as borate based glasses that heal chronic wounds. The re volution looks set to continue as new healthcare applications are being found for bioactive glasses, contributing to extending the glass age

A methodology for the generation and non-destructive characterisation of transverse fractures in long bones

Long bone fractures are common and although treatments are highly effective in most cases, it is challenging to achieve successful repair for groups such as open and periprosthetic fractures. Previous biomechanical studies of fracture repair, including computer and experimental models, have simplified the fracture with a flat geometry or a gap, and there is a need for a more accurate fracture representation to mimic the situation in-vivo. The aims of this study were to develop a methodology for generating repeatable transverse fractures in long bones in-vitro and to characterise the fracture surface using non-invasive computer tomography (CT) methods. Ten porcine femora were fractured in a custom-built rig under high-rate loading conditions to generate consistent transverse fractures (angle to femoral axis < 30 degrees). The bones were imaged using high resolution peripheral quantitative CT (HR-pQCT). A method was developed to extract the roughness and form profiles of the fracture surface from the image data using custom code and Guassian filters. The method was tested and validated using artificially generated waveforms. The results revealed that the smoothing algorithm used in the script was robust but the optimum kernel size has to be considered

Presence of Spotters Improves Bench Press Performance: A Deception Study.

Sheridan, A, Marchant, DC, Williams, EL, Jones, HS, Hewitt, PA, and Sparks, SA. Presence of spotters improves bench press performance: a deception study. J Strength Cond Res XX(X): 000-000, 2017-Resistance exercise is a widely used method of physical training in both recreational exercise and athletic populations. The use of training partners and spotters during resistance exercise is widespread, but little is known about the effect of the presence of these individuals on exercise performance. The purpose of the current study was to investigate the effect of spotter presence on bench press performance. Twelve recreationally trained participants (age, 21.3 ± 0.8 years, height, 1.82 ± 0.1 m, and weight, 84.8 ± 11.1 kg) performed 2 trials of 3 sets to failure at 60% of 1 repetition maximum on separate occasions. The 2 trials consisted of spotters being explicitly present or hidden from view (deception). During the trials, total repetitions (reps), total weight lifted, ratings of perceived exertion (RPE), and self-efficacy were measured. Total reps and weight lifted were significantly greater with spotters (difference = 4.5 reps, t = 5.68, p < 0.001 and difference = 209.6 kg, t = 5.65, p < 0.001, respectively). Although RPE and local RPE were significantly elevated in the deception trials (difference = 0.78, f = 6.16, p = 0.030 and difference = 0.81, f = 5.89, p = 0.034, respectively), self-efficacy was significantly reduced (difference = 1.58, f = 26.90, p < 0.001). This study demonstrates that resistance exercise is improved by the presence of spotters, which is facilitated by reduced RPE and increased self-efficacy. This has important implications for athletes and clients, who should perform resistance exercise in the proximity of others, to maximize total work performed

Culturome versus DNA metabarcoding: Diversity of grapevine endophytic mycobiome in old and young vines of different health status in New Zealand

The grapevine harbours a diverse community of fungi in the woody trunk tissue, termed the “endophytic mycota”. These communities can have a profound effect on the vine’s physiology, health, growth, and ability to adapt to stress. Some of these include pathogenic fungi as the causal agents of grapevine trunk disease (GTD), with many considered latent pathogens. For GTD, understanding the factors affecting latency is still limited. This study aimed to compare the fungal endophyte community in young and old Sauvignon blanc vines, both symptomatic and asymptomatic for GTD, using culture-dependent and culture-independent approaches. Nine vineyards were sampled, with 60 mature vines (>10 years old) and 30 young vines (<9 years old) sampled. Each age group consisted of equal numbers of apparently healthy and symptomatic vines. Trunk cores were taken from each vine using a sterilised 4-mm drill bit after removing the bark with a knife. Fungal communities were characterized by isolation and metabarcoding of the ITS1 region. For the culturome, a collection of 2116 endophytic fungi were recovered, representing 42 fungal genera. Trunk microbiota was dominated by species of the genera Alternaria, Aureobasidium, Diplodia,Epicoccum, Phaeomoniella, Eutypa, Botrytis, Cladosporium, and Diaporthe. Differences in the taxa recovered into culture were observed between vines of different ages, and symptomology. In the metabarcoding approach, 1892 OTUs were obtained. The same fungal genera were identified as the most abundant using metabarcoding. Alpha diversity analysis revealed that greater diversity was detected in old compared to young vines and in asymptomatic compared to symptomatic trunks. Beta diversity analysis demonstrated significant differentiation in the fungal communities structure for both age and health status. This study has produced new baseline information on Sauvignon blanc endophytic mycota and further work will determine the impact of these microbial communities on the latency of GTDs

Fuzzy Fibers: Uncertainty in dMRI Tractography

Fiber tracking based on diffusion weighted Magnetic Resonance Imaging (dMRI) allows for noninvasive reconstruction of fiber bundles in the human brain. In this chapter, we discuss sources of error and uncertainty in this technique, and review strategies that afford a more reliable interpretation of the results. This includes methods for computing and rendering probabilistic tractograms, which estimate precision in the face of measurement noise and artifacts. However, we also address aspects that have received less attention so far, such as model selection, partial voluming, and the impact of parameters, both in preprocessing and in fiber tracking itself. We conclude by giving impulses for future research