Dynamic Compression Enhances Pressure-to-Pain Threshold in Elite Athlete Recovery: Exploratory Study.

Athlete recovery-adaptation is crucial to the progress and performance of highly trained athletes. The purpose of this study was to assess peristaltic pulse dynamic compression (PPDC) in reducing short-term pressure-to-pain threshold (PPT) among Olympic Training Center athletes after morning training. Muscular tenderness and stiffness are common symptoms of fatigue and exercise-induced muscle microtrauma and edema. Twenty-four highly trained athletes (men = 12 and women = 12) volunteered to participate in this study. The athletes were randomly assigned to experimental (n = 12) and control (n = 12) groups. Pressure-to-pain threshold measurements were conducted with a manual algometer on 3 lower extremity muscles. Experimental group athletes underwent PPDC on both legs through computer-controlled circumferential inflated leggings that used a peristaltic-like pressure pattern from feet to groin. Pressures in each cell were set to factory defaults. Treatment time was 15 minutes. The control group performed the same procedures except that the inflation pump to the leggings was off. The experimental timeline included a morning training session, followed by a PPT pretest, treatment application (PPDC or control), an immediate post-test (PPT), and a delayed post-test (PPT) after the afternoon practice session. Difference score results showed that the experimental group's PPT threshold improved after PPDC treatment immediately and persisted the remainder of the day after afternoon practice. The control group showed no statistical change. We conclude that PPDC is a promising means of accelerating and enhancing recovery after the normal aggressive training that occurs in Olympic and aspiring Olympic athletes.

Peristaltic pulse dynamic compression of the lower extremity enhances flexibility.

This study investigated the effects of peristaltic pulse dynamic compression (PPDC) on range-of-motion (ROM) changes in forward splits. Serious stretching usually involves discomfort and large time investments. Tissue structural changes and stretch tolerance have heretofore been considered the primary mechanisms of enhanced ROM. The PPDC treatment was computer controlled. Circumferential and segmented inflation pressures were induced by feet to hip leggings. Nine subjects, experienced in stretching and a forward split position, volunteered. The subjects were familiarized with the protocol and randomly assigned to an initial condition: experimental (PPDC), or control (CONT). The study involved a crossover design. Second conditions were tested within 1-5 days. All tests were 2 trials of right and left forward splits. Split flexibility was assessed by measuring the height of the anterior superior iliac spine of the rear leg from the floor. Pelvic posture was controlled by rear leg position. The PPDC treatment was 15 minutes of seated PPDC. The control condition was the same except that leggings were not inflated. Pressures of 5 cells in the leggings were set at factory defaults, 70 mm Hg sequentially. Difference score results indicated statistically significant (p ≤ 0.05) differences by condition and the condition by leg interaction. The rapid acute changes in ROM (PPDC: right 25.3%, left 33.3%; CONT: right 12.2%, left 1.0%) support the premise that changes in ROM were dependent on mechanisms other than tissue structural changes and/or stretch tolerance. PPDC provides a means of rapidly enhancing acute ROM requiring less discomfort and time.

Alternative procedures for the three-minute all-out exercise test.

The cycling 3-minute all-out exercise test (3 MT) provides the measures of critical power (CP) and the curvature constant (W') for the relationship between power and time limit to exhaustion in the severe exercise domain. The original procedures for the 3 MT required a preliminary graded exercise test (GXT) to establish the linear factor and the fixed load for the test. We evaluated a new procedure of establishing the load for the 3 MT using a percentage of body mass (% BM). Fifteen subjects of varied fitness levels completed a custom GXT-verification protocol to establish the gas exchange threshold and V[Combining Dot Above]O2max, a 3 MT using a load derived with the linear factor, and a 3 MT using a % BM. The subjects also completed a subsequent exhaustive bout at 10% above CP. The CP and W' estimated from either protocol did not differ. The CP estimates were consistent (α = 0.97, SEM = 7.1 W, coefficient of variation = 4%); however, W' was less reliable, a finding true of any method of measuring W'. The V[Combining Dot Above]O2 evoked during the 3 MT was lower than the values evoked by the exhaustive GXT-verification bouts and the 10% above CP bout after the 3 MT. All individual V[Combining Dot Above]O2 values in the 10% above CP bout were "≥" values measured in the 3 MT. Our findings indicate that several viable procedures for administering the 3 MT are plausible.

Acute response of high-intensity and traditional resistance exercise on anaerobic power.

Quantifying the maximal work capacity (W') above the aerobic critical power (CP) has emerged as a method for estimating anaerobic work capacity. Slower cadence, lower-load resistance training (RT), colloquially referred to as high-intensity training (HIT), is purported to be a better metabolic stressor than faster cadence higher-load RT, but to date, this belief has not been supported by research. We compared the acute effects of HIT and traditional RT bouts on average power within a 150-second time period (P(150 s)), CP, and W', as measured from a 3-minute all-out exercise test using cycling ergometry (3 MT). Eight recreationally active male subjects (mean ± SD: age 22 ± 2 years, body mass 85 ± 14 kg, and height 18 ± 9 cm) completed a baseline 3 MT 10 repetition maximum testing on leg press and leg extension machines, and post-bout 3 MTs after an HIT (4:2 second cadence) or a traditional RT bout (1:1 second cadence). Measurements of CP from the 3 MTs were similar between the baseline, post-HIT (α = 0.96), and post-traditional RT bouts (α = 0.98). Neither HIT (269.2 ± 51.3 W) nor traditional RT (275.1 ± 51.3 W) evoked depreciations (p > 0.05) in P(150 s) from the baseline (275.1 ± 45.4 W). Moreover, estimates of W' at the baseline (8.3 ± 3.2 kJ) were unaffected (p > 0.05) either by the HIT (7.6 ± 2.3 kJ) or by the traditional RT (8.3 ± 1.3 kJ) bouts. These data indicate that the 4:2 cadence is insufficient to exhaust a person's capacity for high-intensity work. Longer RT durations, either by slower cadences or by multiple sets, are necessary to evoke substantive declines on W' and should be investigated.

Applying the critical velocity model for an off-season interval training program.

The critical velocity (CV) model offers an opportunity to prescribe and to test empirically different velocity-time (V-t) configurations of high-intensity interval training (HIIT); however, such experiments are lacking. We evaluated a group of competitive, female soccer players (age = 19 ± 1 years, height = 168 ± 6 cm, mass = 61 ± 6 kg) completing 1 of 2 different HIIT regimes: a short group (n = 6) completing higher V and shorter t configurations, and a long group (n = 10) completing lower V, longer t configurations. Both groups trained 2 d·wk for 4 weeks. For each workout, both groups ran at velocities exceeding CV and designed to deplete identical fractional percentages of the finite work capacity above CV (D'). The metrics of CV and D' were evaluated at pretraining and posttraining using the 3-minute all-out exercise test on an indoor track using video digitizing of displacement relative to time. Despite differences in the V-t configurations, both groups increased their CV (+0.22 m·s, +6%) and decreased their D' (-24 m, -13%; p < 0.05). We conclude that 2- to 5-minute HIIT bouts are suitable for increasing CV, in previously trained athletes, but they result in a decline of D'. To increase D', we suggest examining HIIT of intensities that are <2 minutes and >130% of maximum oxygen uptake.

Do the noncaffeine ingredients of energy drinks affect metabolic responses to heavy exercise?

Energy drinks (EDs) such as Red Bull (RB) are marketed to enhance metabolism. Secondary ingredients of EDs (e.g., taurine) have been purported to improve time trial performance; however, little research exists on how such secondary ingredients affect aerobic metabolism during heavy exercise. The purpose of this study was to investigate the effect of the secondary ingredients of RB on aerobic metabolism during and subsequent to heavy exercise. In double-blind, counterbalanced, and crossover fashion, 8 recreationally trained individuals completed a graded exercise test to determine the gas exchange threshold (GET). Subjects returned on 2 separate occasions and ingested either a 245 ml serving of RB or a control (CTRL) drink with the equivalent caffeine before engaging in two 10-minute constant-load cycling bouts, at an intensity equivalent to GET, with 3 minutes of rest between bouts. Accumulated liters of O2 (10 minutes) were higher for the first bout (17.1 ± 3.5 L) vs. the second bout (16.7 ± 3.5 L) but did not differ between drinks. Similarly, excess postexercise oxygen consumption was higher after the initial bout (RB mean, 2.6 ± 0.85 L; CTRL mean, 2.9 ± 0.90 L) vs. the second bout (RB mean, 1.5 ± 0.85 L; CTRL mean, 1.9 ± 0.87 L) but did not differ between drinks. No differences occurred between drinks for measures of heart rate or rating of perceived exertion. These results indicate that the secondary ingredients contained in a single serving of RB do not augment aerobic metabolism during or subsequent to heavy exercise.

Gas exchange threshold and VO2max testing for athletes: an update.

Standardized graded exercise test (GXT) protocols are ineffective for testing endurance athletes. Scientists have called for the abandonment of traditional techniques for corroborating "true" maximum oxygen uptake (VO2max), as measured during a GXT. Instead, a new technique, the verification bout subsequent to the GXT, has emerged for establishing the "true" VO2max. The addition of the verification bout reframes how the GXT should be viewed. In this article, we summarize the methods for developing custom GXT protocols, identifying threshold and interpolating power or outdoor running velocity, and implicating the verification bout.

Effectiveness of the California state ban on the sale of Caulerpa species in aquarium retail stores in southern California.

The invasion of the aquarium strain of the green alga Caulerpa taxifolia and subsequent alteration of community structure in the Mediterranean Sea raised awareness of the potential for non-native seaweeds to impact coastal communities. An introduction of C. taxifolia in southern California in 2000, presumably from the release of aquarium specimens, cost ~$7 million for eradication efforts. Besides C. taxifolia, other Caulerpa species being sold for aquarium use also may have the potential to invade southern Californian and U.S. waters. Surveys of the availability of Caulerpa species in southern California aquarium retail stores in 2000-2001 revealed that 26 of 50 stores sold at least one Caulerpa species (52 %) with seven stores selling C. taxifolia. In late 2001, California imposed a ban on the importation, sale, or possession of nine Caulerpa species; the City of San Diego expanded these regulations to include the entire genus. To determine the effectiveness of the California ban, we resurveyed Caulerpa availability at 43 of the 50 previously sampled retail stores in southern California in ~2006, ~4 years following the ban. Of the 43 stores, 23 sold Caulerpa (53 %) with four stores selling C. taxifolia. A χ(2) test of frequency of availability before and after the California ban suggests that the ban has not been effective and that the aquarium trade continues to represent a potential vector for distributing Caulerpa specimens, including C. taxifolia. This study underscores the need for increased enforcement and outreach programs to increase awareness among the aquarium industry and aquarium hobbyists.

A comparison of pairs figure skaters in repeated jumps.

Trends in pairs figure skating have shown that increasingly difficult jumps have become an essential aspect of high-level performance, especially in the latter part of a competitive program. We compared a repeated jump power index in a 60 s repeated jump test to determine the relationship of repeated jump test to competitive rank and to measure 2D hip, knee, and ankle angles and angular velocities at 0, 20, 40, and 60 s. Eighteen National Team Pairs Figure Skaters performed a 60 s repeated jump test on a large switch-mat with timing of flight and ground durations and digital video recording. Each 60-s period was divided into 6, 10-s intervals, with power indexes (W/kg) calculated for each 10-s interval. Power index by 10-s interval repeated measures ANOVAs (RMANOVA) showed that males exceeded females at all intervals, and the highest power index interval was during 10 to 20 s for both sexes. RMANOVAs of angles and angular velocities showed main effects for time only. Power index and jumping techniques among figure skaters showed rapid and steady declines over the test duration. Power index can predict approximately 50% of competitive rank variance, and sex differences in jumping technique were rare. Key pointsThe repeated jumps test can account for about 50% of the variance in pairs ranks.Changes in technique are largely due to fatigue, but the athletes were able to maintain a maximum flexion knee angle very close to the desired 90 degrees. Changes in angular velocity and jump heights occurred as expected, again probably due to fatigue.As expected from metabolic information, the athletes' power indexes peak around 20s and decline thereafter. Coaches should be aware of this time as a boundary beyond which fatigue becomes more manifest, and use careful choreographic choices to provide rest periods that are disguised as less demanding skating elements to afford recovery.The repeated jumps test may be a helpful off-ice test of power-endurance for figure skaters.

Effect of hang cleans or squats paired with countermovement vertical jumps on vertical displacement.

Complex training is characterized by pairing resistance exercise with plyometric exercise to exploit the postactivation potentiation (PAP) phenomenon, thereby promising a better training effect. Studies on PAP as measured by human power performances are equivocal. One issue may be the lack of analyses across multiple sets of paired exercises, a common practice used by athletes. We evaluated countermovement vertical jump (CMJ) performance in 19 women, collegiate athletes in 3 of the following trials: (a) CMJs-only, where 1 set of CMJs served as a conditioning exercise, (b) heavy-load, back squats paired with CMJs, and (c) hang cleans paired with CMJs. The CMJ vertical displacement (3-attempt average), as measured with digital video, served as the dependent variable of CMJ performance. Across 3 sets of paired-exercise regimens, CMJ-only depreciated 1.6 cm and CMJ paired with back squats depreciated 2.0 cm (main effect, p < 0.05). Conversely, CMJ paired with hang cleans depreciated 0.30 cm (interaction, p < 0.05). Thus, the best complex training scheme was achieved by pairing CMJs with hang cleans in comparison to back squats or CMJs in and of themselves. Future research on exercise modes of complex training that best help athletes preserve and train with the highest power possible, in a given training session, is warranted.

Relating multivariate shapes to genescapes using phenotype-biological process associations for craniofacial shape.

Realistic mappings of genes to morphology are inherently multivariate on both sides of the equation. The importance of coordinated gene effects on morphological phenotypes is clear from the intertwining of gene actions in signaling pathways, gene regulatory networks, and developmental processes underlying the development of shape and size. Yet, current approaches tend to focus on identifying and localizing the effects of individual genes and rarely leverage the information content of high-dimensional phenotypes. Here, we explicitly model the joint effects of biologically coherent collections of genes on a multivariate trait - craniofacial shape - in a sample of n = 1145 mice from the Diversity Outbred (DO) experimental line. We use biological process Gene Ontology (GO) annotations to select skeletal and facial development gene sets and solve for the axis of shape variation that maximally covaries with gene set marker variation. We use our process-centered, multivariate genotype-phenotype (process MGP) approach to determine the overall contributions to craniofacial variation of genes involved in relevant processes and how variation in different processes corresponds to multivariate axes of shape variation. Further, we compare the directions of effect in phenotype space of mutations to the primary axis of shape variation associated with broader pathways within which they are thought to function. Finally, we leverage the relationship between mutational and pathway-level effects to predict phenotypic effects beyond craniofacial shape in specific mutants. We also introduce an online application that provides users the means to customize their own process-centered craniofacial shape analyses in the DO. The process-centered approach is generally applicable to any continuously varying phenotype and thus has wide-reaching implications for complex trait genetics.

Physiological and perceptual responses to exercise according to locus of symptom limitation in COPD.

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease, with pulmonary and extra-pulmonary factors contributing to exercise intolerance. The primary self-reported exercise-limiting symptom may reflect the primary pathophysiological factor contributing to exercise intolerance. We compared physiological and perceptual responses at the symptom-limited peak of incremental cardiopulmonary cycle exercise testing between people with COPD reporting breathlessness (B, n = 34), leg discomfort (LD, n = 16), or a combination of B and LD (BOTH, n = 42) as their main exercise-limiting symptom(s). Despite similarly impaired health status, symptomology and peak exercise capacity, the B group had greater restrictive constraints on tidal volume expansion at end-exercise and was more likely to report unpleasant qualities of exertional breathlessness than LD and BOTH groups. In conclusion, reporting breathlessness as the primary exercise-limiting symptom indicated the presence of distinct lung pathophysiology and symptom perception during exercise in people with COPD.

A case of cutaneous toxigenic Corynebacterium ulcerans likely acquired from a domestic dog.

INTRODUCTION: Corynebacterium ulcerans can produce diphtheria toxin and although still rare, is now the predominant cause of toxigenic diphtheria infection in the UK, making this organism of great clinical and public health importance. Here we describe a cutaneous case, likely secondary to domestic animal contact. CASE PRESENTATION: A 60-year-old female presented with a slow-healing finger-burn wound. A skin swab cultured Corynebacterium ulcerans, which was confirmed to be toxin producing. She resided with her partner and two dogs, one of which had a chronic skin lesion. Her most recent diphtheria vaccine was in 2009. Four close contacts were identified, two of whom were healthcare professionals, and nose and throat swabs were obtained. The patient was treated with clarithromycin (14 day course), diphtheria vaccine and excluded from work until completion of antibiotics and negative clearance swabs. Contacts were given erythromycin (7 day course), vaccinated and healthcare worker contacts excluded from work until swab negative. A veterinary practitioner swabbed the throats and a skin lesion of their dogs. One contact (partner of patient) and all dog swabs were positive. Partial allelic profiles from MLST supported an epidemiological link. The dogs were treated with antibiotics and antimicrobial skin wash. Repeat swabs for the index case, contact and both dogs were negative following treatment. CONCLUSION: This was a rare case of cutaneous diphtheria secondary to Corynebacterium ulcerans with domestic animals the most likely source, although human-to-human contact could not be excluded, with important human and animal public health implications.

Recommendations for Measurement and Management of an Elite Athlete.

Athletes who merit the title 'elite' are rare and differ both quantitatively and qualitatively from athletes of lower qualifications. Serving and studying elite athletes may demand non-traditional approaches. Research involving elite athletes suffers because of the typical nomothetic requirements for large sample sizes and other statistical assumptions that do not apply to this population. Ideographic research uses single-athlete study designs, trend analyses, and statistical process control. Single-athlete designs seek to measure differences in repeated measurements under prescribed conditions, and trend analyses may permit systematic monitoring and prediction of future outcomes. Statistical process control uses control charting and other methods from management systems to assess and modify training processes in near real-time. These methods bring assessment and process control into the real world of elite athletics.

Targeting Nonpulmonary Vein Sources in Persistent Atrial Fibrillation Identified by Noncontact Charge Density Mapping: UNCOVER AF Trial.

Background Identification and elimination of nonpulmonary vein targets may improve clinical outcomes in patients with persistent atrial fibrillation (AF). We report on the use of a novel, noncontact imaging and mapping system that uses ultrasound to reconstruct atrial chamber anatomy and measures timing and density of dipolar, ionic activation (ie, charge density) across the myocardium to guide ablation of atrial arrhythmias. Methods The prospective, nonrandomized UNCOVER AF trial (Utilizing Novel Dipole Density Capabilities to Objectively Visualize the Etiology of Rhythms in Atrial Fibrillation) was conducted at 13 centers across Europe and Canada. Patients with persistent AF (>7 days, <1 year) aged 18 to 80 years, scheduled for de novo catheter ablation, were eligible. Before pulmonary vein isolation, AF was mapped and then iteratively remapped to guide each subsequent ablation of charge density-identified targets. AF recurrence was evaluated at 3, 6, 9, and 12 months using continuous 24-hour ECG monitors. The primary effectiveness outcome was freedom from AF >30 seconds at 12 months for a single procedure with a secondary outcome being acute procedural efficacy. The primary safety outcome was freedom from device/procedure-related major adverse events. Results Between October 2016 and April 2017, 129 patients were enrolled, and 127 underwent mapping and catheter ablation. Acute procedural efficacy was demonstrated in 125 patients (98%). At 12 months, single procedure freedom from AF on or off antiarrhythmic drugs was 72.5% (95% CI, 63.9%-80.3%). After 1 or 2 procedures, freedom from AF was 93.2% (95% CI, 87.1%-97.0%). A total of 29 (23%) retreatments because of arrhythmia recurrence were performed with average time from index procedure to first retreatment being 7 months. The primary safety outcome was 98% with no device-related major adverse events reported. Conclusions This novel ultrasound imaging and charge density mapping system safely guided ablation of nonpulmonary vein targets in persistent AF patients with 73% single procedure and 93% second procedure freedom from AF at 12 months. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT02825992 EU/NCT02462980 CN.

An ecological framework for informing permitting decisions on scientific activities in protected areas.

There are numerous reasons to conduct scientific research within protected areas, but research activities may also negatively impact organisms and habitats, and thus conflict with a protected area's conservation goals. We developed a quantitative ecological decision-support framework that estimates these potential impacts so managers can weigh costs and benefits of proposed research projects and make informed permitting decisions. The framework generates quantitative estimates of the ecological impacts of the project and the cumulative impacts of the proposed project and all other projects in the protected area, and then compares the estimated cumulative impacts of all projects with policy-based acceptable impact thresholds. We use a series of simplified equations (models) to assess the impacts of proposed research to: a) the population of any targeted species, b) the major ecological assemblages that make up the community, and c) the physical habitat that supports protected area biota. These models consider both targeted and incidental impacts to the ecosystem and include consideration of the vulnerability of targeted species, assemblages, and habitats, based on their recovery time and ecological role. We parameterized the models for a wide variety of potential research activities that regularly occur in the study area using a combination of literature review and expert judgment with a precautionary approach to uncertainty. We also conducted sensitivity analyses to examine the relationships between model input parameters and estimated impacts to understand the dominant drivers of the ecological impact estimates. Although the decision-support framework was designed for and adopted by the California Department of Fish and Wildlife for permitting scientific studies in the state-wide network of marine protected areas (MPAs), the framework can readily be adapted for terrestrial and freshwater protected areas.

Large-scale impacts of sea star wasting disease (SSWD) on intertidal sea stars and implications for recovery.

Disease outbreaks can have substantial impacts on wild populations, but the often patchy or anecdotal evidence of these impacts impedes our ability to understand outbreak dynamics. Recently however, a severe disease outbreak occurred in a group of very well-studied organisms-sea stars along the west coast of North America. We analyzed nearly two decades of data from a coordinated monitoring effort at 88 sites ranging from southern British Columbia to San Diego, California along with 2 sites near Sitka, Alaska to better understand the effects of sea star wasting disease (SSWD) on the keystone intertidal predator, Pisaster ochraceus. Quantitative surveys revealed unprecedented declines of P. ochraceus in 2014 and 2015 across nearly the entire geographic range of the species. The intensity of the impact of SSWD was not uniform across the affected area, with proportionally greater population declines in the southern regions relative to the north. The degree of population decline was unrelated to pre-outbreak P. ochraceus density, although these factors have been linked in other well-documented disease events. While elevated seawater temperatures were not broadly linked to the initial emergence of SSWD, anomalously high seawater temperatures in 2014 and 2015 might have exacerbated the disease's impact. Both before and after the onset of the SSWD outbreak, we documented higher recruitment of P. ochraceus in the north than in the south, and while some juveniles are surviving (as evidenced by transition of recruitment pulses to larger size classes), post-SSWD survivorship is lower than during pre-SSWD periods. In hindsight, our data suggest that the SSWD event defied prediction based on two factors found to be important in other marine disease events, sea water temperature and population density, and illustrate the importance of surveillance of natural populations as one element of an integrated approach to marine disease ecology. Low levels of SSWD-symptomatic sea stars are still present throughout the impacted range, thus the outlook for population recovery is uncertain.

Modern Techniques and Technologies Applied to Training and Performance Monitoring.

Athlete preparation and performance continue to increase in complexity and costs. Modern coaches are shifting from reliance on personal memory, experience, and opinion to evidence from collected training-load data. Training-load monitoring may hold vital information for developing systems of monitoring that follow the training process with such precision that both performance prediction and day-to-day management of training become adjuncts to preparation and performance. Time-series data collection and analyses in sport are still in their infancy, with considerable efforts being applied in "big data" analytics, models of the appropriate variables to monitor, and methods for doing so. Training monitoring has already garnered important applications but lacks a theoretical framework from which to develop further. As such, we propose a framework involving the following: analyses of individuals, trend analyses, rules-based analysis, and statistical process control.

Resolving stem and progenitor cells in the adult mouse incisor through gene co-expression analysis.

Investigations into stem cell-fueled renewal of an organ benefit from an inventory of cell type-specific markers and a deep understanding of the cellular diversity within stem cell niches. Using the adult mouse incisor as a model for a continuously renewing organ, we performed an unbiased analysis of gene co-expression relationships to identify modules of co-expressed genes that represent differentiated cells, transit-amplifying cells, and residents of stem cell niches. Through in vivo lineage tracing, we demonstrated the power of this approach by showing that co-expression module members Lrig1 and Igfbp5 define populations of incisor epithelial and mesenchymal stem cells. We further discovered that two adjacent mesenchymal tissues, the periodontium and dental pulp, are maintained by distinct pools of stem cells. These findings reveal novel mechanisms of incisor renewal and illustrate how gene co-expression analysis of intact biological systems can provide insights into the transcriptional basis of cellular identity.

High-risk stress fractures: pathogenesis, evaluation, and treatment.

High-risk stress fractures require precise assessment and treatment because of their propensity for delayed union, nonunion, or complete fracture and their resulting disabling complications. Proper diagnosis necessitates a thorough clinical evaluation, centering on the patient's diet and history, particularly the training regimen. For a definitive diagnosis, plain radiography, ultrasound, bone scintigraphy, magnetic resonance imagery (MRI), and computed tomography (CT) are helpful, and each plays a specific role. High-risk stress fractures typically require aggressive treatment such as nonweight-bearing immobilization coupled with therapy and often surgery.