Publications by authors named "Margarita D Tsiros"

27 Publications

  • Page 1 of 1

Helping Children with Obesity "Move Well" To Move More: An Applied Clinical Review.

Curr Sports Med Rep 2021 Jul;20(7):374-383

Kinesiology Department, Seattle University, Seattle, WA.

Abstract: Children with obesity experience musculoskeletal pain and reduced physical function and well-being, which collectively impact their fitness, strength, motor skills, and even their ability to undertake simple tasks, like walking and climbing stairs. Disrupting obesity-related disability may be critical to increasing children's physical activity. Thus, barriers to movement should be considered by health practitioners to improve the efficacy of prescribed physical activity. This applied clinical review highlights key subjective and objective findings from a hypothetical case scenario, linking those findings to the research evidence, before exploring strategies to enhance movement and increase physical activity.
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http://dx.doi.org/10.1249/JSR.0000000000000861DOI Listing
July 2021

Physiotherapy and related management for childhood obesity: A systematic scoping review.

PLoS One 2021 14;16(6):e0252572. Epub 2021 Jun 14.

Faculty of Health Sciences and Medicine, Bond Institute of Health and Sport, Bond University, Gold Coast, Queensland, Australia.

Introduction: Despite targeted efforts globally to address childhood overweight/obesity, it remains poorly understood and challenging to manage. Physiotherapists have the potential to manage children with obesity as they are experts in movement and physical activity. However, their role remains unclear due to a lack of physiotherapy-specific guidelines. This scoping review aims to explore existing literature, critically appraising and synthesising findings to guide physiotherapists in the evidence-based management of childhood overweight/obesity.

Method: A scoping review was conducted, including literature up to May 2020. A review protocol exists on Open Science Framework at https://osf.io/fap8g/. Four databases were accessed including PubMed, Embase, CINAHL, Medline via OVID, with grey literature searched through google via "file:pdf". A descriptive synthesis was undertaken to explore the impact of existing interventions and their efficacy.

Results: From the initial capture of 1871 articles, 263 intervention-based articles were included. Interventions included qualitative focused physical activity, quantitative focused physical activity and multicomponent interventions. Various outcome measures were utilised including health-, performance- and behaviour-related outcomes. The general trend for physiotherapy involvement with children who are obese appears to favour: 1) multicomponent interventions, implementing more than one component with environmental modification and parental involvement and 2) quantitative physical activity interventions, focusing on the quantity of bodily movement. These approaches most consistently demonstrated desirable changes across behavioural and health-related outcome measures for multicomponent and quantitative physical activity interventions respectively.

Conclusion: When managing children with obesity, physiotherapists should consider multicomponent approaches and increasing the quantity of physical activity, given consistent improvements in various obesity-related outcomes. Such approaches are well suited to the scope of physiotherapists and their expertise in physical activity prescription for the management of childhood obesity. Future research should examine the effect of motor skill interventions and consider the role of environmental modification/parental involvement as factors contributing to intervention success.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0252572PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8202913PMC
June 2021

The Use of Ratings of Perceived Exertion in Children and Adolescents: A Scoping Review.

Sports Med 2021 Jan;51(1):33-50

UniSA Allied Health and Human Performance, Alliance for Research in Exercise, Nutrition and Activity (ARENA), University of South Australia, Adelaide, Australia.

In adults, ratings of perceived exertion (RPE) can be used to predict maximal oxygen uptake, estimate time to exhaustion, assess internal training load and regulate exercise intensity. However, the utility of RPE in children is less researched and therefore, warrants investigation. The purpose of this scoping review is to map out the literature around the application of RPE specifically during aerobic exercise in paediatric populations. Seven bibliographic databases were systematically searched. Grey literature searching and pearling of references were also conducted. To be included for the review, studies were required to comply with the following: (1) participants aged ≤ 18 years asymptomatic of any injuries, disabilities or illnesses; (2) applied RPE in aerobic exercise, testing and/or training; (3) included at least one measure of exercise intensity; and (4) be available in English. The search identified 22 eligible studies that examined the application of RPE in children. These studies involved a total of 718 participants across ten different countries. Nine different types of RPE scales were employed. Overall, the application of RPE in paediatric populations can be classified into three distinct themes: prediction of cardiorespiratory fitness/performance, monitoring internal training loads, and regulation of exercise intensity. The utility of RPE in paediatric populations remains unclear due to the small body of available research and inconsistencies between studies. However, findings from the included studies in this scoping review may show promise. Further research focussing on child-specific RPE scales across various sports, subgroups, and in field-based settings is needed.
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http://dx.doi.org/10.1007/s40279-020-01374-wDOI Listing
January 2021

Obesity, the new childhood disability? An umbrella review on the association between adiposity and physical function.

Obes Rev 2020 Dec 10;21(12):e13121. Epub 2020 Aug 10.

UniSA Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia.

The adverse physical impacts of childhood obesity are increasingly being recognized. The objective of this study is to examine relationships between physical function and adiposity in youth. An umbrella review searched seven databases from inception to May 2019 for systematic reviews examining associations between adiposity and physical function in 0-20-year-olds. Findings were synthesized using the International Classification of Functioning, Disability and Health Framework and NHMRC FORM. Seventeen of 21 systematic reviews reported impairments to body function, including cardiorespiratory fitness (CRF), muscle function, balance/coordination, gait biomechanics, pain and injury. Six reviews reported activity restrictions in motor skills, running speed/agility and functional mobility, and two found inverse associations between adiposity and physical health-related quality of life (p-HRQOL). Some causal relationships indicated that adiposity inversely predicted p-HRQOL/CRF and CRF/muscle function inversely predicted adiposity. Assessments of physical function were heterogeneous and impacts on participation in life situations meaningful to the individual were largely unknown. Substantial evidence associates childhood overweight/obesity with reduced physical function. Associations were mainly cross-sectional, with causative evidence for some outcomes. Comprehensive physical function assessments by qualified health professionals are needed, along with targeted interventions to address deficits. Research should further examine causality of relationships, underlying mechanisms and participation challenges in real-life contexts.
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http://dx.doi.org/10.1111/obr.13121DOI Listing
December 2020

The Physiotherapy in Preschools Program: Describing a Student-Led Assessment Service for Children With Possible Motor Skill Difficulties.

Adapt Phys Activ Q 2020 Jun 19;37(3):324-337. Epub 2020 Jun 19.

University of South Australia.

The aim of this study was to describe and undertake an initial evaluation of a student-led assessment service for children with possible motor-skill difficulties. A secondary analysis of cross-sectional descriptive clinical data collected from 2015 to 2016 was undertaken. Children (N = 102) were assessed in preschools by physiotherapy students (supervised by qualified physiotherapists). Key outcomes included the following: Children's Activities Scale, Movement Assessment Battery for Children-2, and demographic/service-usage/onward referral statistics. The results highlighted that for every five children referred/assessed, two were at risk of motor-skill difficulties (∼43%). About 66% of children were subsequently referred on or monitored (40% requiring multidisciplinary follow-up). Conversely 34% of children did not require further services. In conclusion, a student-led assessment service may be a sustainable and feasible option to assist children at risk of motor-skill difficulties, enabling onward referral. Additional evaluation is required to garner stakeholder feedback.
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http://dx.doi.org/10.1123/apaq.2019-0121DOI Listing
June 2020

The impacts of unstructured nature play on health in early childhood development: A systematic review.

PLoS One 2020 13;15(2):e0229006. Epub 2020 Feb 13.

School of Health Sciences, University of South Australia, Adelaide, Australia.

Background: Nature play is growing in popularity as children's play spaces are transforming from traditional playgrounds into more nature-based play spaces with considerable financial and resource investment from government bodies. This has resulted in the re-development of children's play spaces to incorporate more natural elements such as trees, plants and rocks. Despite this, it is unclear whether there is empirical evidence to support claims that play in nature is beneficial for child health and development.

Aim: To conduct a systematic review examining the impacts of nature play on the health and developmental outcomes of children aged 2-12 years.

Methods: Seven electronic databases were searched (MEDLINE, ERIC, Embase, PsycINFO, The Cochrane Library, The Joanna Briggs Institute and Emcare) from inception to July/August 2018 (search updated July/August 2019). The Inclusion criteria were children aged 2-12 years with no health/developmental conditions. The exposure/intervention of interest was unstructured, free play in nature. Critical appraisal of included studies was conducted using the McMaster Critical Appraisal Tool. Descriptive synthesis was then undertaken using the NHMRC FORM Framework.

Results: Out of 2927 articles identified, 16 studies met the inclusion criteria. The nature play exposure/intervention was heterogeneously described, and a plethora of outcome measures were used. Nature play had consistent positive impacts on physical activity outcomes and cognitive play behaviours (imaginative and dramatic play). However, there remain some concerns regarding the quality of the evidence base, heterogeneity in intervention description and parameters in the outcome measures used.

Conclusions: While the positive impacts of nature play were encouraging in terms of physical activity and cognitive development, nature play stakeholders should focus on producing a universal definition for nature play, the development of standardised outcome measures and the conduct of robust research designs. Implications of these findings suggest the need for the development of standardised guidelines to inform practice and policy in the design of children's play spaces in different contexts.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0229006PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7018039PMC
May 2020

Relationships between adiposity and postural control in girls during balance tasks of varying difficulty.

Obes Res Clin Pract 2019 Jul - Aug;13(4):358-364. Epub 2019 Jun 28.

Centre for Orthopaedic & Trauma Research, Adelaide Medical School, The University of Adelaide, Australia.

Objective: This study aimed to examine associations between postural control and body composition in 8-10-year-old girls.

Methods: An observational cross-sectional study was conducted in 47 girls who were healthy-weight/overweight/obese [body mass index (BMI) percentile]. Girls participated in six postural control conditions of varying difficulty (standing with malleoli touching, tandem stance leading with dominant and non-dominant foot, repeated with eyes open and closed). Postural control outcomes included Centre of Pressure (COP) sway area, COP principal and minor axis length and COP maximum velocity. Data were analysed using linear mixed modelling.

Results: BMI percentile was positively associated with COP sway area (p=0.034) and principal axis (p=0.030) during tandem stance non-dominant foot leading with eyes closed and COP principal axis during tandem stance dominant foot leading with eyes open (p=0.045). BMI percentile significantly interacted with postural control conditions of varying difficulty to predict postural control outcomes (p≤0.035), notable for tandem stance positions [all four COP sway outcomes in tandem stance non-dominant foot leading eyes closed; tandem stance dominant foot leading with eyes open and closed (two COP sway outcomes each)].

Conclusions: Girls with greater adiposity may have impairments in postural control, but only during more challenging postural control conditions. In contrast, BMI has little role to play in girls' postural control in easier postural control conditions (standing with feet together). These findings may suggest potential functional or safety considerations when girls with overweight/obesity are performing demanding postural control tasks (such as during sport or physical activity).
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http://dx.doi.org/10.1016/j.orcp.2019.06.003DOI Listing
June 2020

Take 10! Action Points for Physical Therapists to Consider When It Comes to Childhood Obesity.

Phys Ther 2019 05;99(5):490-493

School of Sport, Exercise, and Nutrition, Massey University, Wellington, New Zealand.

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http://dx.doi.org/10.1093/ptj/pzz016DOI Listing
May 2019

Not all sedentary behaviour is equal: Children's adiposity and sedentary behaviour volumes, patterns and types.

Obes Res Clin Pract 2018 Nov - Dec;12(6):506-512. Epub 2018 Sep 15.

University of South Australia, Alliance for Research in Exercise, Nutrition and Activity (ARENA), School of Health Sciences, Sansom Institute for Health Research, City East Campus, GPO Box 2471, Adelaide, South Australia, 5001, Australia. Electronic address:

Objective: The importance of different constructs of sedentary behaviours in relation to childhood obesity is uncertain. Thus, this study aimed to investigate relationships between volume, patterns and types of sedentary behaviour and adiposity in children.

Methods: A case-control study was undertaken involving 234 children aged 10-13years who were either of a healthy-weight (74 boys, 56 girls) or classified as obese (56 boys, 48 girls). Percent body fat (by dual-energy X-ray absorptiometry) and waist-to-height ratio were assessed. Time, type (television, videogame, computer, eating, passive transport) and bout length of sedentary behaviours were measured using accelerometry and the Multimedia Activity Recall for Children and Adolescents. Time use (total daily energy expenditure, sleep, physical activity), age, household income and Tanner stage were covariates in sex-stratified partial least squares analyses.

Results: Daily energy expenditure and income were negatively associated with adiposity for both sexes. Television time was consistently positively associated with adiposity. In boys only, prolonged bouts of sedentary behaviour and time spent playing video games/computer were positively linked with adiposity. Non-screen sedentary behaviour was negatively associated with adiposity in girls. Independent of total energy expenditure, total sedentary time was only inconsistently associated with fatness.

Conclusions: These data suggest that (1) characteristics of sedentary time other than duration are associated with adiposity in children, and (2) associations may be sex-specific.
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http://dx.doi.org/10.1016/j.orcp.2018.09.001DOI Listing
March 2019

Longer-term effects of minimalist shoes on running performance, strength and bone density: A 20-week follow-up study.

Eur J Sport Sci 2019 Apr 13;19(3):402-412. Epub 2018 Aug 13.

b Alliance for Research in Exercise, Nutrition and Activity, University of South Australia , Adelaide , Australia.

This study investigated whether male runners improve running performance, running economy, ankle plantar flexor strength, and alter running biomechanics and lower limb bone mineral density when gradually transitioning to using minimalist shoes for 100% of weekly running. The study was a planned follow-up of runners (n = 50) who transitioned to minimalist or conventional shoes for 35% of weekly structured training in a previous 6-week randomised controlled trial. In that trial, running performance and economy improved more with minimalist shoes than conventional shoes. Runners in each group were instructed to continue running in their allocated shoe during their own preferred training programme for a further 20 weeks while increasing allocated shoe use to 100% of weekly training. At the 20-week follow-up, minimalist shoes did not affect performance (effect size: 0.19; p = 0.218), running economy (effect size: ≤ 0.24; p ≥ 0.388), stride rate or length (effect size: ≤ 0.12; p ≥ 0.550), foot strike (effect size: ≤ 0.25; p ≥ 0.366), or bone mineral density (effect size: ≤ 0.40; p ≥ 0.319). Minimalist shoes increased plantar flexor strength more than conventional shoes when runners trained with greater mean weekly training distances (shoe*distance interaction: p = 0.036). After greater improvements with minimalist shoes during the initial six weeks of a structured training programme, increasing minimalist shoe use from 35% to 100% over 20 weeks, when runners use their own preferred training programme, did not further improve performance, running economy or alter running biomechanics and lower limb bone mineral density. Minimalist shoes improved plantar flexor strength more than conventional shoes in runners with greater weekly training distances.
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http://dx.doi.org/10.1080/17461391.2018.1505958DOI Listing
April 2019

Use-of-time and health-related quality of life in 10- to 13-year-old children: not all screen time or physical activity minutes are the same.

Qual Life Res 2017 11 3;26(11):3119-3129. Epub 2017 Jul 3.

Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, PO Box 2471, Adelaide, SA, 5001, Australia.

Purpose: To investigate associations between aspects of time use and health-related quality of life (HRQoL) in youth.

Methods: 239 obese and healthy-weight 10- to 13-year-old Australian children completed the Pediatric Quality of Life Inventory (PedsQL™) quantifying their health-related quality of life. Time use was evaluated over four days using the Multimedia Activity Recall for Children and Adolescents (MARCA), a validated 24 h recall tool. The average number of minutes/day spent in physical activity (divided into sport, active transport and play), screen time (divided into television, videogames and computer use), and sleep were calculated. Percent fat was measured using dual-energy X-ray absorptiometry, Tanner stage by self-report, and household income by parental report. Sex-stratified analysis was conducted using Partial Least Squares regression, with percent fat, Tanner stage, household income, and use-of-time as the independent variables, and PedsQL™ total, physical and psychosocial subscale scores as the dependent variables.

Results: For boys, the most important predictors of HRQoL were percent fat (negative), videogames (negative), sport (positive), and Tanner stage (negative). For girls, the significant predictors were percent fat (negative), television (negative), sport (positive), active transport (negative), and household income (positive).

Conclusion: While body fat was the most significant correlate of HRQoL, sport was independently associated with better HRQoL, and television and videogames with poorer HRQoL. Thus, parents and clinicians should be mindful that not all physical activity and screen-based behaviours have equivocal relationships with children's HRQoL. Prospective research is needed to confirm causation and to inform current activity guidelines.
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http://dx.doi.org/10.1007/s11136-017-1639-9DOI Listing
November 2017

Six-week transition to minimalist shoes improves running economy and time-trial performance.

J Sci Med Sport 2017 Dec 21;20(12):1117-1122. Epub 2017 Apr 21.

Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Australia.

Objectives: This study investigated if gradually introducing runners to minimalist shoes during training improved running economy and time-trial performance compared to training in conventional shoes. Changes in stride rate, stride length, footfall pattern and ankle plantar-flexor strength were also investigated.

Design: Randomised parallel intervention trial.

Methods: 61 trained runners gradually increased the amount of running performed in either minimalist (n=31) or conventional (n=30) shoes during a six-week standardised training program. 5-km time-trial performance, running economy, ankle plantar-flexor strength, footfall pattern, stride rate and length were assessed in the allocated shoes at baseline and after training. Footfall pattern was determined from the time differential between rearfoot and forefoot (TD) pressure sensors.

Results: The minimalist shoe group improved time-trial performance (effect size (ES): 0.24; 95% confidence interval (CI): 0.01, 0.48; p=0.046) and running economy (ES 0.48; 95%CI: 0.22, 0.74; p<0.001) more than the conventional shoe group. There were no minimalist shoe training effects on ankle plantar-flexor concentric (ES: 0.11; 95%CI: -0.18, 0.41; p=0.45), isometric (ES: 0.23; 95%CI: -0.17, 0.64; p=0.25), or eccentric strength (ES: 0.24; 95%CI: -0.17, 0.65; p=0.24). Minimalist shoes caused large reductions in TD (ES: 1.03; 95%CI: 0.65, 1.40; p<0.001) but only two runners changed to a forefoot footfall. Minimalist shoes had no effect on stride rate (ES: 0.04; 95%CI: -0.08, 0.16; p=0.53) or length (ES: 0.06; 95%CI: -0.06, 0.18; p=0.35).

Conclusions: Gradually introducing minimalist shoes over a six-week training block is an effective method for improving running economy and performance in trained runners.
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http://dx.doi.org/10.1016/j.jsams.2017.04.013DOI Listing
December 2017

Body Mass and Weekly Training Distance Influence the Pain and Injuries Experienced by Runners Using Minimalist Shoes: A Randomized Controlled Trial.

Am J Sports Med 2017 Apr 27;45(5):1162-1170. Epub 2017 Jan 27.

Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia.

Background: Minimalist shoes have been popularized as a safe alternative to conventional running shoes. However, a paucity of research is available investigating the longer-term safety of minimalist shoes.

Purpose: To compare running-related pain and injury between minimalist and conventional shoes in trained runners and to investigate interactions between shoe type, body mass, and weekly training distance.

Study Design: Randomized clinical trial; Level of evidence, 2.

Methods: Sixty-one trained, habitual rearfoot footfall runners (mean ± SD: body mass, 74.6 ± 9.3 kg; weekly training distance, 25 ± 14 km) were randomly allocated to either minimalist or conventional shoes. Runners gradually increased the time spent running in their allocated shoes over 26 weeks. Running-related pain intensity was measured weekly by use of 100-mm visual analog scales. Time to first running-related injury was also assessed.

Results: Interactions were found between shoe type and weekly training distance for weekly running-related pain; greater pain was experienced with minimalist shoes ( P < .05), and clinically meaningful increases (>10 mm) were noted when the weekly training distance was more than 35 km/wk. Eleven of 30 runners sustained an injury in conventional shoes compared with 16 of 31 runners in minimalist shoes (hazard ratio, 1.64; 95% confidence interval, 0.63-4.27; P = .31). A shoe × body mass interaction was found for time to first running-related injury ( P = .01). For runners using minimalist shoes, relative to runners using conventional shoes, the risk of sustaining an injury became more likely with increasing body mass above 71.4 kg, and the risk was moderately increased (hazard ratio, 2.00; 95% confidence interval, 1.10-3.66; P = .02) for runners using minimalist shoes who had a body mass of 85.7 kg.

Conclusions: Runners should limit weekly training distance in minimalist shoes to avoid running-related pain. Heavier runners are at greater risk of injury when running in minimalist shoes. Registration: Australian New Zealand Clinical Trials Registry (ACTRN12613000642785).
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http://dx.doi.org/10.1177/0363546516682497DOI Listing
April 2017

Redistribution of Mechanical Work at the Knee and Ankle Joints During Fast Running in Minimalist Shoes.

J Athl Train 2016 Oct 11;51(10):806-812. Epub 2016 Nov 11.

Alliance for Research in Exercise, Nutrition, and Activity, University of South Australia, Adelaide.

Context: Minimalist shoes have been suggested as a way to alter running biomechanics to improve running performance and reduce injuries. However, to date, researchers have only considered the effect of minimalist shoes at slow running speeds.

Objective: To determine if runners change foot-strike pattern and alter the distribution of mechanical work at the knee and ankle joints when running at a fast speed in minimalist shoes compared with conventional running shoes.

Design: Crossover study.

Setting: Research laboratory.

Patients Or Other Participants: Twenty-six trained runners (age = 30.0 ± 7.9 years [age range, 18-40 years], height = 1.79 ± 0.06 m, mass = 75.3 ± 8.2 kg, weekly training distance = 27 ± 15 km) who ran with a habitual rearfoot foot-strike pattern and had no experience running in minimalist shoes.

Intervention(s): Participants completed overground running trials at 18 km/h in minimalist and conventional shoes.

Main Outcome Measure(s): Sagittal-plane kinematics and joint work at the knee and ankle joints were computed using 3-dimensional kinematic and ground reaction force data. Foot-strike pattern was classified as rearfoot, midfoot, or forefoot strike based on strike index and ankle angle at initial contact.

Results: We observed no difference in foot-strike classification between shoes (χ = 2.29, P = .13). Ankle angle at initial contact was less (2.46° versus 7.43°; t = 3.34, P = .003) and strike index was greater (35.97% versus 29.04%; t = 2.38, P = .03) when running in minimalist shoes compared with conventional shoes. We observed greater negative (52.87 J versus 42.46 J; t = 2.29, P = .03) and positive work (68.91 J versus 59.08 J; t = 2.65, P = .01) at the ankle but less negative (59.01 J versus 67.02 J; t = 2.25, P = .03) and positive work (40.37 J versus 47.09 J; t = 2.11, P = .046) at the knee with minimalist shoes compared with conventional shoes.

Conclusions: Running in minimalist shoes at a fast speed caused a redistribution of work from the knee to the ankle joint. This finding suggests that runners changing from conventional to minimalist shoes for short-distance races could be at an increased risk of ankle and calf injuries but a reduced risk of knee injuries.
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http://dx.doi.org/10.4085/1062-6050-51.12.05DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5189234PMC
October 2016

Effects of a minimalist shoe on running economy and 5-km running performance.

J Sports Sci 2016 Sep 11;34(18):1740-5. Epub 2016 Jan 11.

a Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research , University of South Australia , Adelaide , SA , Australia.

The purpose of this study was to determine if minimalist shoes improve time trial performance of trained distance runners and if changes in running economy, shoe mass, stride length, stride rate and footfall pattern were related to any difference in performance. Twenty-six trained runners performed three 6-min sub-maximal treadmill runs at 11, 13 and 15 km·h(-1) in minimalist and conventional shoes while running economy, stride length, stride rate and footfall pattern were assessed. They then performed a 5-km time trial. In the minimalist shoe, runners completed the trial in less time (effect size 0.20 ± 0.12), were more economical during sub-maximal running (effect size 0.33 ± 0.14) and decreased stride length (effect size 0.22 ± 0.10) and increased stride rate (effect size 0.22 ± 0.11). All but one runner ran with a rearfoot footfall in the minimalist shoe. Improvements in time trial performance were associated with improvements in running economy at 15 km·h(-1) (r = 0.58), with 79% of the improved economy accounted for by reduced shoe mass (P < 0.05). The results suggest that running in minimalist shoes improves running economy and 5-km running performance.
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http://dx.doi.org/10.1080/02640414.2015.1136071DOI Listing
September 2016

Tracking Performance Changes With Running-Stride Variability When Athletes Are Functionally Overreached.

Int J Sports Physiol Perform 2017 Mar 24;12(3):357-363. Epub 2016 Aug 24.

Purpose: Stride-to-stride fluctuations in running-stride interval display long-range correlations that break down in the presence of fatigue accumulated during an exhaustive run. The purpose of the study was to investigate whether long-range correlations in running-stride interval were reduced by fatigue accumulated during prolonged exposure to a high training load (functional overreaching) and were associated with decrements in performance caused by functional overreaching.

Methods: Ten trained male runners completed 7 d of light training (LT), 14 d of heavy training (HT) designed to induce a state of functional overreaching, and 10 d of light training (LT) in a fixed order. Running-stride intervals and 5-km time-trial (5TT) performance were assessed after each training phase. The strength of long-range correlations in running-stride interval was assessed at 3 speeds (8, 10.5, and 13 km/h) using detrended fluctuation analysis.

Results: Relative to performance post-LT, time to complete the 5TT was increased after HT (+18 s; P < .05) and decreased after LT (-20 s; P = .03), but stride-interval long-range correlations remained unchanged at HT and LT (P > .50). Changes in stride-interval long-range correlations measured at a 10.5-km/h running speed were negatively associated with changes in 5TT performance (r -.46; P = .03).

Conclusions: Runners who were most affected by the prolonged exposure to high training load (as evidenced by greater reductions in 5TT performance) experienced the greatest reductions in stride-interval long-range correlations. Measurement of stride-interval long-range correlations may be useful for monitoring the effect of high training loads on athlete performance.
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http://dx.doi.org/10.1123/ijspp.2015-0618DOI Listing
March 2017

The effect of footwear and footfall pattern on running stride interval long-range correlations and distributional variability.

Gait Posture 2016 Feb 13;44:137-42. Epub 2015 Dec 13.

Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Adelaide, SA, 5001, Australia.

The presence of long-range correlations (self-similarity) in the stride-to-stride fluctuations in running stride interval has been used as an indicator of a healthy adaptable system. Changes to footfall patterns when running with minimalist shoes could cause a less adaptable running gait. The purpose of this study was to investigate stride interval variability and the degree of self-similarity of stride interval in runners wearing minimalist and conventional footwear. Twenty-six trained habitual rearfoot footfall runners, unaccustomed to running in minimalist footwear, performed 6-min sub-maximal treadmill running bouts at 11, 13 and 15 km·h(-1) in minimalist and conventional shoes. Force sensitive resistors were placed in the shoes to quantify stride interval (time between successive foot contacts). Footfall position, stride interval mean and coefficient of variation (CV), were used to assess performance as a function of shoe type. Long-range correlations of stride interval were assessed using detrended fluctuation analysis (α). Mean stride interval was 1-1.3% shorter (P=0.02) and 27% of runners adopted a midfoot footfall (MFF) in the minimalist shoe. There was a significant shoe effect on α and shoe*speed*footfall interaction effect on CV (P<0.05). Runners that adopted a MFF in minimalist shoes, displayed reduced long-range correlations (P<0.05) and CV (P<0.06) in their running stride interval at the 15 km·h(-1) speed. The reduced variability and self-similarity observed for runners that changed to a MFF in the minimalist shoe may be suggestive of a system that is less flexible and more prone to injury.
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http://dx.doi.org/10.1016/j.gaitpost.2015.12.006DOI Listing
February 2016

Impaired Physical Function Associated with Childhood Obesity: How Should We Intervene?

Child Obes 2016 Apr 29;12(2):126-34. Epub 2016 Jan 29.

1 Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia , Adelaide, South Australia, Australia .

Background: This study examined relationships between adiposity, physical functioning, and physical activity.

Methods: Obese (N = 107) and healthy-weight (N = 132) children aged 10-13 years underwent assessments of percent body fat (%BF, dual energy X-ray absorptiometry); knee extensor strength (KE, isokinetic dynamometry); cardiorespiratory fitness (CRF, peak oxygen uptake by cycle ergometry); physical health-related quality of life (HRQOL); and worst pain intensity and walking capacity [six-minute walk (6MWT)]. Structural equation modelling was used to assess relationships between variables.

Results: Moderate relationships were observed between %BF and (1) 6MWT, (2) KE strength corrected for mass, and (3) CRF relative to mass (r -0.36 to -0.69, p ≤ 0.007). Weak relationships were found between %BF and physical HRQOL (r -0.27, p = 0.008); CRF relative to mass and physical HRQOL (r -0.24, p = 0.003); physical activity and 6MWT (r 0.17, p = 0.004). Squared multiple correlations showed that 29.6% variance in physical HRQOL was explained by %BF, pain, and CRF relative to mass; while 28.0% variance in 6MWT was explained by %BF and physical activity.

Conclusions: It appears that children with a higher body fat percentage have poorer KE strength, CRF, and overall physical functioning. Reducing percent fat appears to be the best target to improve functioning. However, a combined approach to intervention, targeting reductions in body fat percentage, reductions in pain, and improvements in physical activity and CRF may assist physical functioning.
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http://dx.doi.org/10.1089/chi.2015.0123DOI Listing
April 2016

The long-term effect of minimalist shoes on running performance and injury: design of a randomised controlled trial.

BMJ Open 2015 Aug 21;5(8):e008307. Epub 2015 Aug 21.

Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia.

Introduction: The outcome of the effects of transitioning to minimalist running shoes is a topic of interest for runners and scientists. However, few studies have investigated the longer term effects of running in minimalist shoes. The purpose of this randomised controlled trial (RCT) is to investigate the effects of a 26 week transition to minimalist shoes on running performance and injury risk in trained runners unaccustomed to minimalist footwear.

Methods And Analysis: A randomised parallel intervention design will be used. Seventy-six trained male runners will be recruited. To be eligible, runners must be aged 18-40 years, run with a habitual rearfoot footfall pattern, train with conventional shoes and have no prior experience with minimalist shoes. Runners will complete a standardised transition to either minimalist or control shoes and undergo assessments at baseline, 6 and 26 weeks. 5 km time-trial performance (5TT), running economy, running biomechanics, triceps surae muscle strength and lower limb bone mineral density will be assessed at each time point. Pain and injury will be recorded weekly. Training will be standardised during the first 6 weeks. Primary statistical analysis will compare 5TT between shoe groups at the 6-week time point and injury incidence across the entire 26-week study period.

Ethics And Dissemination: This RCT has been approved by the Human Research Ethics Committee of the University of South Australia. Participants will be required to provide their written informed consent prior to participation in the study. Study findings will be disseminated in the form of journal publications and conference presentations after completion of planned data analysis.

Trial Registration Number: This RCT has been registered with the Australian New Zealand Clinical Trials Registry (ACTRN12613000642785).
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http://dx.doi.org/10.1136/bmjopen-2015-008307DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4550712PMC
August 2015

The reliability of dual-energy X-ray absorptiometry measurements of bone mineral density in the metatarsals.

Skeletal Radiol 2016 Jan 8;45(1):135-40. Epub 2015 Aug 8.

Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, South Australia, 5001, Australia.

Objective: To investigate the reliability of a simple, efficient technique for measuring bone mineral density (BMD) in the metatarsals using dual-energy X-ray absorptiometry (DXA).

Materials And Methods: BMD of the right foot of 32 trained male distance runners was measured using a DXA scanner with the foot in the plantar position. Separate regions of interest (ROI) were used to assess the BMD of each metatarsal shaft (1st-5th) for each participant. ROI analysis was repeated by the same investigator to determine within-scan intra-rater reliability and by a different investigator to determine within-scan inter-rater reliability. Repeat DXA scans were undertaken for ten participants to assess between-scan intra-rater reliability.

Results: Assessment of BMD was consistently most reliable for the first metatarsal across all domains of reliability assessed (intra-class correlation coefficient [ICC] ≥0.97; coefficient of variation [CV] ≤1.5%; limits of agreement [LOA] ≤4.2%). Reasonable levels of intra-rater reliability were also achieved for the second and fifth metatarsals (ICC ≥0.90; CV ≤4.2%; LOA ≤11.9%). Poorer levels of reliability were demonstrated for the third (ICC ≥0.64; CV ≤8.2%; LOA ≤23.6%) and fourth metatarsals (ICC ≥0.67; CV ≤9.6%; LOA ≤27.5%). BMD was greatest in the first and second metatarsals (P < 0.01).

Conclusion: Reliable measurements of BMD were achieved for the first, second and fifth metatarsals.
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http://dx.doi.org/10.1007/s00256-015-2227-0DOI Listing
January 2016

The effect of footwear on running performance and running economy in distance runners.

Sports Med 2015 Mar;45(3):411-22

Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA, 5001, Australia,

Background: The effect of footwear on running economy has been investigated in numerous studies. However, no systematic review and meta-analysis has synthesised the available literature and the effect of footwear on running performance is not known.

Objective: The aim of this systematic review and meta-analysis was to investigate the effect of footwear on running performance and running economy in distance runners, by reviewing controlled trials that compare different footwear conditions or compare footwear with barefoot.

Methods: The Web of Science, Scopus, MEDLINE, CENTRAL (Cochrane Central Register of Controlled Trials), EMBASE, AMED (Allied and Complementary Medicine), CINAHL and SPORTDiscus databases were searched from inception up until April 2014. Included articles reported on controlled trials that examined the effects of footwear or footwear characteristics (including shoe mass, cushioning, motion control, longitudinal bending stiffness, midsole viscoelasticity, drop height and comfort) on running performance or running economy and were published in a peer-reviewed journal.

Results: Of the 1,044 records retrieved, 19 studies were included in the systematic review and 14 studies were included in the meta-analysis. No studies were identified that reported effects on running performance. Individual studies reported significant, but trivial, beneficial effects on running economy for comfortable and stiff-soled shoes [standardised mean difference (SMD) <0.12; P < 0.05), a significant small beneficial effect on running economy for cushioned shoes (SMD = 0.37; P < 0.05) and a significant moderate beneficial effect on running economy for training in minimalist shoes (SMD = 0.79; P < 0.05). Meta-analysis found significant small beneficial effects on running economy for light shoes and barefoot compared with heavy shoes (SMD < 0.34; P < 0.01) and for minimalist shoes compared with conventional shoes (SMD = 0.29; P < 0.01). A significant positive association between shoe mass and metabolic cost of running was identified (P < 0.01). Footwear with a combined shoe mass less than 440 g per pair had no detrimental effect on running economy.

Conclusions: Certain models of footwear and footwear characteristics can improve running economy. Future research in footwear performance should include measures of running performance.
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http://dx.doi.org/10.1007/s40279-014-0283-6DOI Listing
March 2015

Musculoskeletal pain in obese compared with healthy-weight children.

Clin J Pain 2014 Jul;30(7):583-8

*Nutritional Physiology Research Centre, School of Health Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA †School of Health Sciences, RMIT University, Melbourne, Vic ‡Mater Mothers' Hospital, Mater Research and Centre for Musculoskeletal Research, Griffith Health Institute, Griffith University, Nathan, QLD, Australia.

Objectives: To investigate whether obesity is associated with musculoskeletal pain in children.

Materials And Methods: Obese (n=107) and healthy-weight (n=132) 10- to 13-year-old children (132 males, 107 females) participated in an observational case-control study. Children self-reported pain location (excluding abdominal pain), pain intensity (current and prior week), and pain prevalence (overall and lower limb) using the Pediatric Pain Questionnaire. Body composition was assessed (dual-energy x-ray absorptiometry) and children wore an accelerometer for 8 days.

Results: After adjustment for accelerometry (weekly average counts per hour) and socioeconomic status, obese children had more intense pain (worst pain, P=0.006), pain in more locations (P≤0.005), and a higher prevalence of lower limb pain (60% vs. 52% respectively, P=0.012) than healthy-weight children. Significant relationships were observed between body mass index and total pain locations (P≤0.004, unadjusted and adjusted) and worst pain intensity (P≤0.009, adjusted for socioeconomic status/accelerometry). There were no significant relationships between percent body fat and pain variables (unadjusted/adjusted analyses, P=0.262 to 1.0).

Discussion: Obesity in children was associated with increased overall and lower limb musculoskeletal pain, for which body mass index was a stronger predictor than adiposity. Clinicians treating obese children should screen for pain and prescribe exercise programs that take their symptoms into account.
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http://dx.doi.org/10.1097/AJP.0000000000000017DOI Listing
July 2014

Knee extensor strength differences in obese and healthy-weight 10-to 13-year-olds.

Eur J Appl Physiol 2013 Jun 12;113(6):1415-22. Epub 2012 Dec 12.

Nutritional Physiology Research Centre, School of Health Sciences, Sansom Institute for Health Research, University of South Australia, PO Box 2471, Adelaide, SA 5001, Australia.

The purpose of this study was to investigate if obese children have reduced knee extensor (KE) strength and to explore the relationship between adiposity and KE strength. An observational case-control study was conducted in three Australian states, recruiting obese [N = 107 (51 female, 56 male)] and healthy-weight [N = 132 (56 female, 76 male)] 10- to 13-year-old children. Body mass index, body composition (dual energy X-ray absorptiometry), isokinetic/isometric peak KE torques (dynamometry) and physical activity (accelerometry) were assessed. Results revealed that compared with their healthy-weight peers, obese children had higher absolute KE torques (P ≤ 0.005), equivocal KE torques when allometrically normalized for fat-free mass (FFM) (P ≥ 0.448) but lower relative KE torques when allometrically normalized for body mass (P ≤ 0.008). Adjustments for maternal education, income and accelerometry had little impact on group differences, except for isometric KE torques relative to body mass which were no longer significantly lower in obese children (P ≥ 0.013, not significant after controlling for multiple comparisons). Percent body fat was inversely related to KE torques relative to body mass (r = -0.22 to -0.35, P ≤ 0.002), irrespective of maternal education, income or accelerometry. In conclusion, while obese children have higher absolute KE strength and FFM, they have less functional KE strength (relative to mass) available for weight-bearing activities than healthy-weight children. The finding that FFM-normalized KE torques did not differ suggests that the intrinsic contractile properties of the KE muscles are unaffected by obesity. Future research is needed to see if deficits in KE strength relative to mass translate into functional limitations in weight-bearing activities.
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http://dx.doi.org/10.1007/s00421-012-2561-zDOI Listing
June 2013

Test-retest reliability of the Biodex System 4 Isokinetic Dynamometer for knee strength assessment in paediatric populations.

J Allied Health 2011 ;40(3):115-9

Nutritional Physiology Research Centre, School of Health Sciences, University of South Australia, Adelaide, SA, Australia.

Background: Isokinetic dynamometry is a widely used tool for measuring muscle strength in clinical intervention and rehabilitation as well as research in children.

Objective: To assess the test-retest reliability of knee flexor/extensor strength using the Biodex Multi-Joint System 4 Isokinetic Dynamometer in children.

Methods: Peak isometric knee extensor (KE) and peak isokinetic knee flexor (KF) torques of the dominant and nondominant limbs were assessed twice in 11 children aged 10 to 13 yrs, 7 to 10 days apart.

Results: Peak torques were higher in the dominant limb (p ≤ 0.006). Peak isometric KE torque was 8.4% higher (SEM 2.5%) at the second testing session, but there was no interaction with the limb tested (p > 0.2). Peak isokinetic KE/KF torque ratios agreed well between tests and had intraclass correlation coefficients (ICCs) of 0.96.

Conclusions: The dynamometer provides a reliable means of assessing knee strength in 10 to 13 year olds, with excellent test-retest reliability for isokinetic KE/KF. A learning effect occurred when assessing isometric torque, indicating the importance of habituation for this measure.
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January 2012

The Biodex isokinetic dynamometer for knee strength assessment in children: advantages and limitations.

Work 2011 ;39(2):161-7

Nutritional Physiology Research Centre, Sansom Institute for Health Research, University of South Australia, Australia.

Objective: To critically appraise the Biodex System 4 isokinetic dynamometer for strength assessment of children.

Methods: Appraisal was based on experiences from two independent laboratories involving testing of 213 children. Issues were recorded and the manufacturer was consulted regarding appropriate solutions.

Results: The dynamometer had insufficient height adjustment for alignment of the knee for some children, requiring the construction of padding to better fit the child within the dynamometer. Potential for entrapment of the non-testing leg was evident in the passive and eccentric modes and a leg bracket restraint was constructed. Automated gravity correction did not operate when protocols were linked or data was exported to an external device.

Conclusions: Limitations were noted, some of which were applicable to knee strength testing in general and others which were specific to use with children. However, most of these obstacles could be overcome, making the Biodex System 4 suitable for assessment of knee strength in children.
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http://dx.doi.org/10.3233/WOR-2011-1162DOI Listing
December 2011

Cognitive behavioral therapy improves diet and body composition in overweight and obese adolescents.

Am J Clin Nutr 2008 May;87(5):1134-40

Australian Technology Network Centre for Metabolic Fitness, School of Health Sciences, University of South Australia, Adelaide, Australia.

Background: Cognitive behavioral therapy (CBT) teaches behavioral and cognitive strategies that focus on achieving and maintaining lifestyle changes.

Objective: We examined the effectiveness of a CBT program (CHOOSE HEALTH) for improving body composition, diet, and physical activity in overweight and obese adolescents.

Design: Adolescents [16 male, 31 female; aged 14.5 +/- 1.6 y; body mass index (BMI; in kg/m(2)) 30.9 +/- 4.2] were block-matched into 2 groups by age, sex, Tanner stage, BMI, and hip and waist circumferences and were randomly assigned to CBT or no treatment (control). CBT consisted of 10 weekly sessions, followed by 5 fortnightly telephone sessions.

Results: Compared with the control, over 20 wk, CBT improved (significant group x time interactions) BMI (CBT, -1.3 +/- 0.4; control, 0.3 +/- 0.3; P = 0.007), weight (CBT, -1.9 +/- 1.0 kg; control, 3.8 +/- 0.9 kg; P = 0.001), body fat (CBT, -1.5 +/- 0.9 kg; control, 2.3 +/- 1.0 kg; P = 0.001), and abdominal fat (CBT, -124.0 +/- 46.9 g; control, 50.1 +/- 53.5 g; P = 0.008). CBT showed a greater reduction in intake of sugared soft drinks as a percentage of total energy (CBT, -4.0 +/- 0.9%; control, -0.3 +/- 0.9%; P = 0.005 for group x time interaction), which was related to reductions in weight (r = 0.48, P = 0.04), BMI (r = 0.53, P = 0.02), and waist circumference (r = 0.54, P = 0.02). Physical activity did not change significantly.

Conclusions: A 10-wk CBT program followed by 10 wk of fortnightly phone contact improved body composition in overweight and obese adolescents. Changes in soft drink consumption may have contributed to this benefit.
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http://dx.doi.org/10.1093/ajcn/87.5.1134DOI Listing
May 2008

Treatment of adolescent overweight and obesity.

Eur J Pediatr 2008 Jan 1;167(1):9-16. Epub 2007 Nov 1.

Nutritional Physiology Research Centre and ATN Centre for Metabolic Fitness, School of Health Sciences, University of South Australia, P.O. Box 2471, Adelaide, SA 5001, Australia.

Adolescence is a vulnerable period for the development of obesity, and adolescent weight tracks strongly into adulthood. Previous reviews of treatment strategies have failed to discriminate between adolescents and children, thereby, disregarding the uniqueness of this population. Hence, this review aims to summarise the evidence for treatment approaches for adolescent obesity. Pubmed, OVID, EBSCOhost and Google Scholar were searched for randomised controlled trials, meta-analyses and systematic reviews testing treatments for overweight/obese adolescents (aged 12-19 years), published from 1982-2006 in English. Eligible studies had to assess either weight, percentage overweight, body mass index (BMI) or body fat. Thirty-four randomised controlled trials were eligible. The results of this review indicate that the safety and efficacy of surgical and pharmacotherapy treatments for adolescent obesity is uncertain. Diet and physical activity approaches may improve obese status in the short term. However, obesity interventions appear more effective when strategies are combined, rather than when used in isolation. Psychological interventions, such as behavioural and cognitive behavioural therapy, show promise in achieving the necessary lifestyle changes for obesity reduction; however, long-term follow-up studies are needed. There were multiple limitations in appraising the literature. Inconsistent definitions of overweight/obesity make comparisons between studies difficult. Many studies have not used direct adiposity measures, have failed to assess pubertal status or have not used an exclusive adolescent sample. We conclude that, despite these limitations, current evidence indicates that behavioural and cognitive behavioural strategies combined with diet and physical activity approaches may assist in reducing adolescent obesity,although long-term follow-up studies are needed.
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http://dx.doi.org/10.1007/s00431-007-0575-zDOI Listing
January 2008
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