Ecological Momentary Assessment to Explore Fatigue, Mood, and Physical Activity Levels in People Receiving Peritoneal Dialysis.

Introduction: Fatigue is a frequent and debilitating symptom that contributes to poor quality of life for people receiving peritoneal dialysis. Ecological momentary assessment using mobile technology (mEMA) is a novel survey technique that can collect symptom data in real-time and has not been trialed in a peritoneal dialysis cohort. The study aimed to explore real-time fluctuations and associations between fatigue, mood, and physical activity using mEMA. Methods: Adults receiving peritoneal dialysis completed fatigue and mood scales, via a mobile application (app), 5 times daily for 7 days and, concurrently wore an accelerometer. A feasibility questionnaire was completed on the eighth day. Results: Forty-eight adults completed the study. Within-day fatigue fluctuations were observed with severity lowest during mid-morning to early afternoon and peaking at bedtime. Associations between fatigue and mood were observed with a 1-unit change in mood score conferring a 5.2-unit change in fatigue (P < 0.01). Higher volume of physical activity was associated with lower fatigue and enhanced mood. Overall adherence to the app-based surveys was 73% with most participants reporting mobile phones and the mEMA app being easy to use. Conclusion: People receiving peritoneal dialysis experience within day and day-to-day fluctuations in fatigue that appear highly variable. Higher fatigue severity was associated with poorer mood and lower physical activity levels with future studies required to explore if physical activity-based interventions could be a potential strategy for the management of these symptoms. Furthermore, mEMA, and mobile phones, were feasible to capture symptom data with potential to be employed in future research or, as part of improved care.

Single-Leg Heel Raise Capacity is Lower, and Perceived Ankle Instability is Greater, in Dancers and Athletes With Posterior Ankle Impingement Syndrome.

OBJECTIVE: To compare clinical assessment findings between elite athletic populations with and without a clinical diagnosis of posterior ankle impingement syndrome (PAIS). DESIGN: Cross-sectional case-control study. SETTING: Elite ballet and sport. PARTICIPANTS: Ten male and female professional ballet dancers and athletes with a clinical diagnosis of PAIS and were matched for age, sex, and activity to 10 professional ballet dancers and athletes without PAIS. INDEPENDENT VARIABLES: Posterior ankle pain on body chart and a positive ankle plantarflexion pain provocation test. MAIN OUTCOME MEASURES: Single-leg heel raise (SLHR) endurance test, range of motion testing for weight-bearing ankle dorsiflexion, passive ankle plantarflexion, and first metatarsophalangeal joint dorsiflexion, and Beighton score for generalized joint hypermobility. Participants also completed the Cumberland Ankle Instability Tool (CAIT) questionnaire. RESULTS: The group with PAIS achieved significantly fewer repetitions on SLHR capacity testing (P = 0.02) and were more symptomatic for perceived ankle instability according to CAIT scores (P = 0.004). CONCLUSIONS: Single-leg heel raise endurance capacity was lower, and perceived ankle instability was greater in participants with PAIS. The management of this presentation in elite dancers and athletes should include the assessment and management of functional deficits.

The Effects of Pointe Shoes on Ballet Dancers' Biomechanics, Muscle Activity, Movement and Symptoms: A Scoping Review.

Introduction: Dancing en pointe requires ballet dancers to stand on the tips of their toes while wearing a structured pointe shoe. Understanding the effect of pointe shoes on ballet dancers' biomechanics, function, symptoms and skin health is essential to guide shoe development and ultimately improve dancer performance. Therefore, the purpose of this scoping review was to map the evidence and identify knowledge gaps related to the effect of wearing pointe shoes on professional and recreational ballet dancers. Method: A scoping review was conducted by searching 6 electronic databases and the International Association for Dance Medicine and Science Bibliography. Results: Thirty-five studies were grouped into 5 categories: pointe shoe factors (eg, toe box and shank, pointe shoe status; 9 studies), shoe types (eg, flat shoes vs demi pointe vs pointe; 10 studies), ballet movements (11 studies), symptoms (5 studies), and intrinsic dancer factors (eg, foot type/toe length; 7 studies). Studies were published between 1979 and 2023, with 72% (n = 23) published between 2006 and 2020. Most (86%) of the studies were cross-sectional. Most studies explored biomechanical outcomes and the most common data collection device was force plates (19 studies). Overall, there was an insufficient volume of evidence for specific research aims. Significant gaps in knowledge exist regarding functional and performance-based outcomes, injury outcomes including exploration of factors such as shoe age/usage, and pointe shoe treatment factors. Conclusions: Currently the field of research suffers from threats to ecological validity, with many study methods not reflecting ballet-specific demands or environments. The impact of pointe shoes on ballet dancers is a developing research area, and this scoping review can help guide future research decisions. Studies need to target the knowledge gaps and employ rigorous ecologically valid study designs and ensure that findings inform shoe design and dancer education to minimize injury and maximize comfort and performance.

"A sprained ankle is the biggest sign of mental fatigue": A qualitative study of the perceptions and experiences of mental fatigue in professional ballet.

Mental fatigue is known to influence endurance, skill, and tactical performance in sport. Research investigating the impact of mental fatigue on tasks that combine physical, cognitive, and aesthetic performance such as professional ballet does not exist. OBJECTIVE: To understand the perceptions and experiences of mental fatigue in professional ballet. DESIGN: Qualitative, focus groups and semi-structured interviews. SETTING: The Australian Ballet. PARTICIPANTS: Thirty-nine professional ballet dancers (53% of the company) and six dance staff members aged 18 years or above (53% female). MAIN OUTCOME MEASURES: N/a. RESULTS: The average focus group and interview length was 48 ± 7 min and 41 ± 8 min. Key categories were; (1) Dancers and dance staff perceive that new learning contributes to mental fatigue, (2) Dancers perceive changes to their mood and perception of effort when they are mentally fatigued, and (3) Dancers and dance staff perceive that mental fatigue negatively affects their physical and cognitive performance and, increases their risk of injury. CONCLUSION: This is the first study where participants associated mental fatigue with injury risk and provides a springboard to measure the impact of mental fatigue on learning, injury, and performance in professional ballet.

Characteristics and Frequency of Physical Activity and Exercise-Related Side Effects in People Receiving Peritoneal Dialysis.

OBJECTIVE: People receiving peritoneal dialysis may receive health benefits from physical activity or exercise. However, on-going uncertainty and fear regarding safety may result in this population missing out on the health benefits of participation. The aim of this study was to explore the characteristics and frequency of physical activity and/or exercise-related side effects (e.g., symptoms such as pain or shortness of breath) and negative health events (e.g., stroke or hyper/hypoglycemia) experienced by people receiving peritoneal dialysis. METHODS: An international online survey involving adults receiving peritoneal dialysis was conducted with questions related to nature, occurrence, and impact of side effects and/or negative health events experienced during or soon after participation in physical activity or exercise. RESULTS: Fifty-two people completed the survey reporting 151 side effects that were related to physical activity and exercise and 67 that were possibly related. Fatigue (58% of respondents), muscle/joint soreness or pain (54%), and dizziness (43%) were the most frequently reported side-effect types. The majority occurred occasionally (58% of all side effects), if not rarely (24%) and participation in on-going physical activity or exercise was typically prevented only occasionally (39%) or not at all (31%). Side effects were mainly self-managed (54% of all side effects) or did not require treatment (19%) and had low (38%) or no effect (30%) on ability to do daily activities. CONCLUSIONS: People receiving peritoneal dialysis generally experience side effects that can be considered a normal response to physical activity or exercise engagement. Furthermore, the risk of serious or peritoneal dialysis-specific side effects as a result of physical activity or exercise appears to be low. The results add to the emerging evidence suggesting physical activity and exercise appear to be safe for people receiving peritoneal dialysis.

Posterior Ankle Impingement Syndrome Clinical Features Are Not Associated With Imaging Findings in Elite Ballet Dancers and Athletes.

OBJECTIVE: To assess the association between clinical features and magnetic resonance imaging (MRI) findings in posterior ankle impingement syndrome (PAIS) and to compare the prevalence of imaging findings between participants with and without a clinical diagnosis of PAIS. DESIGN: Case-control study. SETTING: Elite ballet and sport. PARTICIPANTS: Eighty-two male (54%) and female participants comprising ballet dancers (n = 43), cricket fast bowlers (n = 24), and football (soccer) players (n = 15). INDEPENDENT VARIABLES: Clinical: posterior ankle pain on body chart, passive plantarflexion pain provocation test. Patient-reported outcome measures: Oslo Sports Trauma Research Center Overuse Injury Questionnaire, Foot and Ankle Ability Measure Sports subscale. MAIN OUTCOME MEASURES: Imaging findings including posterior ankle bone marrow edema, os trigonum (± bone marrow edema, and increased signal at synchondrosis), Stieda process (± bone marrow edema), talocrural and subtalar joint effusion-synovitis size, flexor hallucis longus tendinopathy, and tenosynovitis identified as present or absent on 3.0-Tesla MRI. RESULTS: Imaging findings were not associated with posterior ankle pain or a positive ankle plantarflexion pain provocation test. Imaging findings were not associated with patient-reported outcome measures. Imaging findings did not differ between PAIS-positive and PAIS-negative groups. Os trigonum and Stieda process were prevalent despite clinical status. CONCLUSIONS: The lack of association between imaging findings and clinical features questions the role of imaging in PAIS. Clinicians should rely primarily on clinical assessment in the diagnosis and management of patients with PAIS.

Exercise or physical activity-related adverse events in people receiving peritoneal dialysis: A systematic review.

People receiving peritoneal dialysis (PD) may benefit from participation in exercise or physical activity. However, exercise therapy for people receiving PD is not typically included in routine care, in part, due to ongoing uncertainties about risk. The aim of this review was to systematically collate and explore data on adverse events experienced by people receiving PD while undertaking an exercise or physical activity intervention. Searches yielded 25 exercise or physical activity intervention studies involving people receiving PD. Of these 25 studies, 17 studies provided adverse event data and were included in the final review. No serious adverse events (e.g. death, hospitalisation) were found attributable to the intervention. From 50 reported adverse events during the intervention period, 32 were attributable to the exercise or physical activity intervention with most being musculoskeletal (e.g. muscle/joint pain, etc.) followed by fatigue. Most events were mild to moderate in severity and resolved by exercise programme modification, education, rest or medication. The results from this review did not uncover signals of harm for people receiving PD who engage in exercise with risk of adverse events appearing to be low, however, improved adverse events reporting and further interventional studies are required before robust guidelines can be produced.

Chronic Stress and Arthritis: A Scoping Review.

OBJECTIVE: Emerging research supports the role of chronic stress in chronic disease development. The objective was to perform a scoping review mapping the field of research exploring relationships between chronic stress and the development of arthritis in adult populations. METHODS: Five electronic databases were systematically searched without publication limits based on 3 key concepts: stress, arthritis, and adults. Eligible qualitative studies investigated individuals' perceived causes of arthritis; quantitative studies investigated relationships between exposure to a chronic stressor and an arthritis presence outcome. Articles were screened by 2 independent reviewers, and data were narratively synthesized. RESULTS: Of 1,819 unique records, 54 studies met inclusion criteria. Nine studies used qualitative methods, and 45 used quantitative methods. The frequency of studies increased chronologically, with half (n = 27) published since 2010. Chronic stress exposures were heterogenous; most were categorized as adverse life events (n = 22) or adverse childhood experiences (n = 17). Self-reported arthritis was the most frequent measure of arthritis outcome (n = 26) in quantitative studies. A majority of studies (n = 41) suggested a relationship between exposure to chronic stressors and arthritis development. CONCLUSION: Increasing study numbers in the past decade may reflect increasing awareness of the potential impact of chronic stress in arthritis development, consistent with a biopsychosocial approach to chronic disease etiology and management. Further research, using precise arthritis definitions, conducted within a clearly articulated pathophysiologic framework, is required to establish a causal relationship between exposure to chronic stressors and the development of specific arthritis conditions.

Associations between clinical and imaging findings in posterior ankle impingement syndrome: a systematic review.

BACKGROUND: Posterior ankle impingement syndrome (PAIS) is a common and debilitating condition, commonly affecting people who participate in activities that involve repetitive ankle plantarflexion. The relationship between clinical and imaging findings in PAIS has not been established. PURPOSE: To investigate the relationship between clinical and imaging features in PAIS by reviewing the literature comparing symptomatic patients to asymptomatic controls. MATERIAL AND METHODS: A systematic literature search was performed to identify all English-language articles that compared imaging features in patients diagnosed with PAIS to imaging in an asymptomatic control group. RESULTS: A total of 8394 articles were evaluated by title and abstract, and 156 articles were read in full text. No articles compared imaging findings to an asymptomatic control group, thus no articles met the inclusion criteria. CONCLUSION: This systematic review found no published research that compared the imaging findings of people diagnosed with PAIS to asymptomatic people. Until this information is available, imaging features in people with posterior ankle impingement should be interpreted with caution.

Schedules of standing and sitting directed by musculoskeletal discomfort in workers transitioning to sit-stand workstations: a cross-sectional study.

Sit-stand workstations are growing in popularity, however limited guidelines exist regarding optimal schedules of sitting and standing. This was the first known study to observe sit-stand workstation schedules when postural change is based on maintaining musculoskeletal discomfort within 'acceptable' levels. Fourteen healthy adults new to sit-stand workstations completed computer-based work at a sit-stand desk for half a workday. Participants changed between standing and sitting postures each time discomfort reached the maximum acceptable threshold. On average, the amount of standing and sitting was greatest in the first standing (median 40 minutes, interquartile range 40 minutes) and sitting (median 30 minutes, interquartile range 115 minutes) bouts. Average durations spent standing and sitting were lower in all consecutive bouts. Stand-sit ratios indicated an equal amount of standing to sitting or somewhat less standing. The schedules had substantial inter-participant variability. Future studies should consider that optimal schedules may vary with regard to time and be individual-specific.

Refined guidelines are needed regarding effective use of sit-stand workstations. This study proposed a novel method of investigating potentially optimal schedules, in which postural change was based on reaching a threshold of musculoskeletal discomfort. The findings suggest that an optimal schedule may vary with time and be individual-specific. Abbreviations: BMI: body mass index; Borg CR-10 scale: Borg Category Ratio-10 scale; IQR: interquartile range; LMD questionnaire: the localised musculoskeletal discomfort questionnaire; MHT: maximum holding time; SD: standard deviation.

Deep hip external rotator muscle size in ballet dancers compared to non-dancing athletes, and associations to pain.

OBJECTIVES: To compare the deep hip external rotator (DHER) muscle (piriformis, gemelli, quadratus femoris (QF)) cross-sectional area (CSA) in dancers and athletes and evaluate the relationship between DHER size and hip pain. STUDY DESIGN: Cross-sectional study. SETTING: Elite ballet and sport. PARTICIPANTS: 33 professional ballet dancers and 33 age and sex-matched athletes. MAIN OUTCOME MEASURES: CSAs of piriformis, gemelli and QF on magnetic resonance imaging (MRI). Hip pain scored with the Copenhagen Hip and Groin Outcome Score (HAGOS): Hip pain was categorised as 'yes' if HAGOS pain score was <100, 'no' if HAGOS pain was = 100. RESULTS: Estimated marginal mean CSA of piriformis, gemelli and QF muscles was similar in athletes and dancers (p > 0.05), and CSAs were not associated with hip pain. Male and female dancers had similar sized DHER muscles. In athletes, CSA of piriformis was 55% (p = 0.02, Cohen's d(95%CI) = 0.98 (0.26,1.71)) and the gemelli were 34% (p = 0.03, Cohen's d(95%CI) = 0.98 (0.26,1.70)) larger in men than women; QF was 36% larger (p = 0.08, Cohen's d(95%CI) = 0.77 (0.06,1.48)). CONCLUSION: Although ballet dancers perform in external rotation, their DHER are no larger than athletes and muscle size was not associated with hip pain.

Magnetic resonance imaging findings associated with posterior ankle impingement syndrome are prevalent in elite ballet dancers and athletes.

OBJECTIVE: To report the prevalence of MRI features commonly associated with posterior ankle impingement syndrome in elite ballet dancers and athletes and to compare findings between groups. MATERIALS AND METHODS: Thirty-eight professional ballet dancers (47.4% women) were age- and sex-matched to 38 elite soccer or cricket fast bowler athletes. All participants were training, playing, and performing at full workload and underwent 3.0-T standardised magnetic resonance imaging of one ankle. De-identified images were assessed by one senior musculoskeletal radiologist for findings associated with posterior ankle impingement syndrome (os trigonum, Stieda process, posterior talocrural and subtalar joint effusion-synovitis, flexor hallucis longus tendon pathology and tenosynovitis, and posterior ankle bone marrow oedema). Imaging scoring reliability testing was performed. RESULTS: Posterior talocrural effusion-synovitis (90.8%) and subtalar joint effusion-synovitis (93.4%) were common in both groups, as well as the presence of either an os trigonum or Stieda process (61.8%). Athletes had a higher prevalence of either os trigonum or Stieda process than dancers (74%, 50% respectively, P = 0.03). Male athletes had a higher prevalence of either os trigonum or Stieda process than male dancers (90%, 50% respectively, P = 0.01), or female athletes (56%, P = 0.02). Posterior subtalar joint effusion-synovitis size was larger in dancers than athletes (P = 0.02). Male and female dancers had similar imaging findings. There was at least moderate interobserver and intraobserver agreement for most MRI findings. CONCLUSION: Imaging features associated with posterior impingement were prevalent in all groups. The high prevalence of os trigonum or Stieda process in male athletes suggests that this is a typical finding in this population.

Compliance With Mobile Ecological Momentary Assessment of Self-Reported Health-Related Behaviors and Psychological Constructs in Adults: Systematic Review and Meta-analysis.

BACKGROUND: Mobile ecological momentary assessment (mEMA) permits real-time capture of self-reported participant behaviors and perceptual experiences. Reporting of mEMA protocols and compliance has been identified as problematic within systematic reviews of children, youth, and specific clinical populations of adults. OBJECTIVE: This study aimed to describe the use of mEMA for self-reported behaviors and psychological constructs, mEMA protocol and compliance reporting, and associations between key components of mEMA protocols and compliance in studies of nonclinical and clinical samples of adults. METHODS: In total, 9 electronic databases were searched (2006-2016) for observational studies reporting compliance to mEMA for health-related data from adults (>18 years) in nonclinical and clinical settings. Screening and data extraction were undertaken by independent reviewers, with discrepancies resolved by consensus. Narrative synthesis described participants, mEMA target, protocol, and compliance. Random effects meta-analysis explored factors associated with cohort compliance (monitoring duration, daily prompt frequency or schedule, device type, training, incentives, and burden score). Random effects analysis of variance (P≤.05) assessed differences between nonclinical and clinical data sets. RESULTS: Of the 168 eligible studies, 97/105 (57.7%) reported compliance in unique data sets (nonclinical=64/105 [61%], clinical=41/105 [39%]). The most common self-reported mEMA target was affect (primary target: 31/105, 29.5% data sets; secondary target: 50/105, 47.6% data sets). The median duration of the mEMA protocol was 7 days (nonclinical=7, clinical=12). Most protocols used a single time-based (random or interval) prompt type (69/105, 65.7%); median prompt frequency was 5 per day. The median number of items per prompt was similar for nonclinical (8) and clinical data sets (10). More than half of the data sets reported mEMA training (84/105, 80%) and provision of participant incentives (66/105, 62.9%). Less than half of the data sets reported number of prompts delivered (22/105, 21%), answered (43/105, 41%), criterion for valid mEMA data (37/105, 35.2%), or response latency (38/105, 36.2%). Meta-analysis (nonclinical=41, clinical=27) estimated an overall compliance of 81.9% (95% CI 79.1-84.4), with no significant difference between nonclinical and clinical data sets or estimates before or after data exclusions. Compliance was associated with prompts per day and items per prompt for nonclinical data sets. Although widespread heterogeneity existed across analysis (I2>90%), no compelling relationship was identified between key features of mEMA protocols representing burden and mEMA compliance. CONCLUSIONS: In this 10-year sample of studies using the mEMA of self-reported health-related behaviors and psychological constructs in adult nonclinical and clinical populations, mEMA was applied across contexts and health conditions and to collect a range of health-related data. There was inconsistent reporting of compliance and key features within protocols, which limited the ability to confidently identify components of mEMA schedules likely to have a specific impact on compliance.

Ecological momentary assessment to explore fatigue, mood and physical activity levels in people receiving peritoneal dialysis: A study protocol.

INTRODUCTION: Fatigue is a frequent and debilitating symptom for people with end-stage kidney disease (ESKD) receiving dialysis. Ecological momentary assessment (EMA) allows real-time data capture of day-to-day and diurnal variations. EMA has been used to study haemodialysis-related fatigue but not in people receiving peritoneal dialysis who are unique in their physical, environmental and logistical characteristics. The aim of this study is to explore the real-time associations between fatigue and mood (EMA mobile application) and objective physical activity levels (accelerometry) in people with EKSD receiving peritoneal dialysis. METHOD: A 7-day intensive longitudinal study will be conducted. People receiving peritoneal dialysis within South Australia will be invited to participate. Five times throughout the day, participants will be prompted to answer 18 questions relating to fatigue (Visual Analogue Scale to Evaluate Fatigue Severity) and a single question for mood (Visual Analogue Mood Scale). Participants will continuously wear a GENEActiv accelerometer to capture physical activity levels during the 7-day period. At the completion of the data collection, participants will answer questions to evaluate the feasibility and acceptability of using EMA. DISCUSSION: This study will be the first to explore the real-time relationships between fatigue, mood and physical activity in people with ESKD receiving peritoneal dialysis. Understanding the fluctuations people experience and the relationships between mood and physical activity and fatigue will inform clinical management and well-being intervention development.

Temporal Trends in the Standing Broad Jump Performance of 10,940,801 Children and Adolescents Between 1960 and 2017.

BACKGROUND: The standing broad jump (SBJ) is an excellent functional measure of explosive lower-body strength that is significantly related to health among children and adolescents. OBJECTIVES: The aim of this study was to estimate national (country-level) and international (pooled global data) temporal trends in SBJ performance for children and adolescents, and to examine the relationships between national trends in SBJ performance and national trends in health-related and socioeconomic/demographic indicators. METHODS: Data were obtained from a systematic search of studies reporting temporal trends in SBJ performance for 9- to 17-year-olds, and by examining national fitness datasets. Sample-weighted regression models estimated trends at the study/dataset-country-sex-age level, with national and international trends estimated by a post-stratified population-weighting procedure. Pearson's correlations quantified relationships between national trends in SBJ performance and national trends in health-related and socioeconomic/demographic indicators. RESULTS: Data from 34 studies/datasets were extracted to estimate trends for 10,940,801 children and adolescents from 24 high-, 4 upper-middle-, and 1 low-income countries between 1960 and 2017. Collectively, there was a negligible (per decade) improvement in SBJ performance of 1.73 cm (95% CI 1.71-1.75), 0.99% (95% CI 0.97-1.01) or a standardized effect size of 0.07 (0.07-0.07) over the entire period, with the rate of improvement steady from the 1960s to the 1980s, slowing in the 1990s, before declining. Sex- and age-related temporal differences were negligible. Trends differed between countries, with most countries experiencing declines. National trends in SBJ performance were not significantly related to national trends in health-related and socioeconomic/demographic indicators. CONCLUSIONS: SBJ performance of children and adolescents has declined since 2000 (at least among most of the countries in this analysis) and is suggestive of a modern decline in functional explosive lower-body strength. Growing recognition of the importance of muscular fitness as a marker of population health highlights the need for continued tracking of temporal trends in SBJ, especially among low- and lower-middle-income countries for which temporal data are lacking. PROSPERO REGISTRATION NUMBER: CRD42013003657.

Self-Reported Wellness in Training and Performance: A Comparison of Professional Ballet Dancers and Professional Athletes.

OBJECTIVE: In high-performance sport, the use of self-report measures is expanding. The exploration of wellness states in response to training and performance requires further investigation for professional ballet dancers and athletes. This study therefore aimed to: compare wellness scores between professional ballet dancers and athletes in training and performance; report frequency of self-reported modified participation during training and performance; and report frequency of self-reported inability to participate due to pain and illness in dancers and athletes. METHODS: Fourteen professional ballet dancers (mean 26 yrs, SD 2.6) and 14 sex- and age-matched professional athletes (mean 27.7 yrs, SD 2.9) recorded daily wellness (fatigue, stress, sleep quality and quantity), participation (full, rest, modified, or unable to participate) and activity (performance, training) into a wellness application on their smart phone over a 4-month period. Mixed factorial ANOVAs were conducted to assess the interaction between group (ballet dancers and athletes) and activity (performance and training) on the dependent variables (stress, fatigue, sleep quality, and sleep quantity). RESULTS: Stress and fatigue levels were higher for both dancers and athletes during performance compared to training periods. Dancers recorded lower sleep quantity than athletes, with no difference in sleep quality. Modified participation appears more common in dancers compared to athletes. Dancers and athletes were rarely unable to train or perform/compete over the 4 months. CONCLUSION: Self-reported wellness scores appear sensitive to activity type and can provide valuable information to guide intervention and recovery strategies. Further research on the impact of poor wellness on performance, illness, and injury in professional ballet is warranted.

Validity and Reliability of Hand-Held Dynamometry for Abdominal Flexion Muscular Assessment.

CONTEXT: Abdominal musculature underpins core stability, which can allow for optimal performance in many activities of daily living (eg, walking and rising from a chair). Therefore, assessment of the abdominal muscles poses as an important consideration for clinicians in order to identify people at risk of injury or functional decline. OBJECTIVE: This study aimed to build on the limited amount of knowledge surrounding abdominal muscle strength assessments by investigating the validity and reliability of hand-held dynamometry (HHD) for the assessment of isometric abdominal flexion strength. STUDY DESIGN AND PARTICIPANTS: Comparative analysis for validity and test-retest reliability was employed on a cohort of apparently healthy individuals. HHD was compared with the criterion, isokinetic dynamometry, through an isometric contraction of trunk flexion on both instruments. Hand-held dynamometry assessments only were performed on a subsequent day for reliability analysis. The peak values for all assessments were recorded. RESULTS: A total of 35 participants were recruited from the University of South Australia and the general public. Comparative analysis between the HHD and isokinetic dynamometer showed good agreement (intraclass correlation coefficients = .82), with the Bland-Altman plots confirming no proportional bias. Reliability analysis for the HHD reported good consistency (intraclass correlation coefficients = .87). CONCLUSION: HHD together with the participant setup (supine, trunk flexed, and supported at 25° with the legs horizontal and remaining unfixed) is a valid and reliable tool to assess isometric abdominal flexion strength.

Temporal trends in the sit-ups performance of 9,939,289 children and adolescents between 1964 and 2017.

We estimated international/national temporal trends in sit-ups performance for children and adolescents, and examined relationships between national trends in sit-ups performance and national trends in health-related/sociodemographic indicators. Data were obtained by systematically searching studies reporting on temporal trends in sit-ups performance for apparently healthy 9-17 year-olds, and by examining nationally representative fitness datasets. Trends at the country-sex-age level were estimated by sample-weighted regression models relating the testing year to mean sit-ups performance. International/national trends were estimated by a post-stratified population-weighting procedure. Pearson's correlations quantified relationships between national trends in sit-ups performance and national trends in health-related/sociodemographic indicators. A total of 9,939,289 children and adolescents from 31 countries/special administrative regions between 1964 and 2017 collectively showed a large improvement of 38.4% (95% CI: 36.8 to 40.0) or 7.1% per decade (95% CI: 6.8 to 7.4). Large international improvements were experienced by all age and sex groups, with the rate of improvement slowing from 1964 to 2000, stabilizing near zero until 2010, before declining. Trends differed between countries, with national trends in vigorous physical activity a strong, positive correlate of national trends in sit-ups performance. More sit-ups data are needed from low- and middle-income countries to better monitor trends in muscular fitness. PROSPERO REGISTRATION NUMBER: CRD42013003657.

Dyspnoea Assessment In Adults With End-Stage Kidney Disease: A Systematic Review.

BACKGROUND: Dyspnoea is a common, disabling symptom of people living with end-stage kidney disease (ESKD), which may persist despite optimal management. Dyspnoea assessments can be grouped according to the instruments that assess domains related to: sensory-perception (intensity, sensory quality), affective distress (unpleasantness) and impact/burden (function, quality of life). OBJECTIVES: To describe dyspnoea assessment in adults with ESKD receiving renal replacement therapy (RRT). DESIGN: Systematic review. METHODS: Five databases were searched. Primary studies reporting an assessment of dyspnoea in adults with ESKD receiving RRT were included. Studies were excluded where participants with ESKD had received palliative/conservative treatment (no dialysis) or renal transplant. Conference abstracts, protocols, commentaries and/or images were excluded. Two independent reviewers screened and extracted the data. Descriptive analysis summarised the (1) number and type of instruments used to assess dyspnoea; (2) which dyspnoea domains to be assessed and (3) rationale and context for dyspnoea assessment. RESULTS: From 2,234 records screened, 28 studies were eligible for inclusion (observational n = 22 and experimental n = 6). Across studies, 12 different instruments were identified (dyspnoea-specific n = 3, subscale of a comprehensive instrument n = 9). Most instruments (n = 11, 92%) assessed a single domain (intensity n = 6, unpleasantness n = 6 and impact/burden n = 5). Studies reported a rationale for measuring dyspnoea (n = 26) as either a characteristic of the participant cohort (n = 14) or as an outcome (n = 14). CONCLUSIONS: Surprisingly, a few primary studies reported assessment of dyspnoea in people with ESKD receiving RRT. When assessed, there was a predominance of unidimensional instruments. As dyspnoea is associated with adverse clinical outcomes, routine dyspnoea assessment may improve management and relieve suffering.

Modifiable Physical Factors Associated With Physical Functioning for Patients Receiving Dialysis: A Systematic Review.

BACKGROUND: Patients receiving dialysis have reduced physical function, which is associated with unfavorable clinical outcomes and decreased quality of life. The authors aimed to identify and explore modifiable physical factors associated with physical function for patients receiving dialysis. METHODS: Searches were performed in MEDLINE, Embase, Ovid Emcare, and The Cochrane Library in October 2018. Etiological studies involving dialysis populations that report association or predictive statistics between a modifiable physical factor and physical function were eligible for inclusion. Predictor variables were (1) modifiable via exercise and (2) considered an impairment in the International Classification of Functioning, Disability and Health. RESULTS: Of 5384 titles screened, 23 studies were included. Thirteen studies focused on physical activity levels and muscle strength and the relationship with physical function while 2 studies investigated sedentary behavior. Twenty-one studies focused on hemodialysis populations. Studies related to physical activity levels displayed a moderately strong relationship with physical function, whereas muscle strength displayed a predominantly weak to moderate relationship. CONCLUSIONS: Physical activity levels, sedentary behavior levels, and muscle strength are related to physical function status for patients receiving dialysis. There is a need for robust longitudinal data to confirm the results of this investigation and for more focus on populations receiving peritoneal dialysis.