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Journal Cover Journal of Sport and Health Science
  [18 followers]  Follow
    
  This is an Open Access Journal Open Access journal
   ISSN (Print) 2095-2546
   Published by Elsevier Homepage  [2805 journals]
  • Relationships among hamstring muscle optimal length and hamstring
           flexibility and strength

    • Abstract: Publication date: Available online 21 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Xianglin Wan, Feng Qu, William E. Garrett, Hui Liu, Bing Yu
      Background Hamstring muscle strain injury (hamstring injury) due to excessive muscle strain is one of the most common injuries in sports. The relationships among hamstring muscle optimal lengths and hamstring flexibility and strength were unknown, which limited our understanding of risk factors for hamstring injury. This study was aimed at examining the relationships among hamstring muscle optimal lengths and flexibility and strength. Methods Hamstring flexibility and isokinetic strength data and three-dimensional (3D) kinematic data for hamstring isokinetic tests were collected for 11 male and 10 female recreational athletes. The maximal hamstring muscle forces, optimal lengths, and muscle lengths in standing were determined for each participant. Results Hamstring muscle optimal lengths were significantly correlated to hamstring flexibility score and gender, but not to hamstring strength. The greater the flexibility score, the longer the hamstring muscle optimal length. With the same flexibility score, females tend to have shorter hamstring optimal muscle lengths compared to males. Hamstring flexibility score and hamstring strength were not correlated. Hamstring muscle optimal lengths were longer than but not significantly correlated to corresponding hamstring muscle lengths in standing. Conclusion Hamstring flexibility may affect hamstring muscle maximum strain in movements. With similar hamstring flexibility, hamstring muscle maximal strain in a given movement may be different between genders. Hamstring muscle lengths in standing should not be used as an approximation of their optimal lengths in calculation of hamstring muscle strain in musculoskeletal system modeling.


      PubDate: 2016-04-26T15:24:08Z
       
  • What is the most effective exercise protocol to improve cardiovascular
           fitness in overweight and obese subjects?

    • Abstract: Publication date: Available online 21 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Eliane Aparecida Castro, Ana Belén Peinado, Pedro Jose Benito, Mercedes Galindo, Marcela González-Gross, Rocío Cupeiro
      Background Increased peak oxygen consumption (VO2peak) can reduce cardiovascular risks associated with obesity. Our aim was to analyze the effect of a weight loss program on cardiovascular fitness in overweight (W) and obese (O) subjects. Methods One hundred sixty-seven subjects (77 males and 90 females), aged 18–50 years, performed a modified Bruce protocol before (pre) and after (post) a weight loss program of 24 weeks. This program combined physical training (strength, S; endurance, E; combined strength + endurance, SE; or physical activity recommendation, PA) 3 times per week, with a 25%-30 % caloric restriction diet. Results In overweight and obese males, VO2peak improved (pre and post values in L/min, respectively; W = 3.2 ± 0.6 vs. 3.7 ± 0.5, p < 0.001; O = 3.6 ± 0.6 vs. 3.8 ± 0.6, p = 0.013), as well as in overweight females (2.0 ± 0.3 vs. 2.3 ± 0.4, p < 0.001). VO2 in the first ventilatory threshold (VT1) increased for all 4 interventions in men (p < 0.05), except for S in the obese group (1.6 ± 0.2 vs. 1.7 ± 0.3, p = 0.141). In females, it increased in E (0.9 ± 0.2 vs. 1.4 ± 0.3, p < 0.001), SE (0.9 ± 0.2 vs. 1.2 ± 0.4, p = 0.003), and PA (0.9 ± 0.1 vs. 1.2 ± 0.2, p = 0.006) overweight groups. Time-to-exhaustion improved in all subjects except for women in PA group (15.7 ± 0.3 vs. 15.9 ± 0.3, p = 0.495). Conclusion Our results suggest that all methods, including the recommendation of physical activity, can improve cardiovascular fitness in overweight subjects and obese males.


      PubDate: 2016-04-26T15:24:08Z
       
  • Training session intensity affects plasma redox status in amateur rhythmic
           gymnasts

    • Abstract: Publication date: Available online 21 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Marianna Bellafiore, Antonino Bianco, Giuseppe Battaglia, Maria Silvia Naccari, Giovanni Caramazza, Johnny Padulo, Karim Chamari, Antonio Paoli, Antonio Palma
      Purpose The aim of this study was to examine systemic responses of oxidant/antioxidant status following 2 training sessions of different intensity in amateur rhythmic gymnasts. Methods Before the experimental training, 10 female gymnasts performed a gradually increased exercise test to assess maximal heart rate, maximal oxygen consumption, and anaerobic threshold. They executed two intermittent training sessions separated by 48 h of recovery (48 h-post R): the first was performed at low-moderate intensity (LMI) and the second at high intensity (HI). Blood samples were collected immediately pre- and post-training and 48 h-post R. Hydroperoxide level (OxL) and total antioxidant capacity (TAC) were photometrically measured. Results OxL was significantly higher in post-training and 48 h-post R following HI than the same conditions after an LMI session [(HI vs. LMI post-training: 381.10 ± 46.17 U vs. 344.18 ± 27.94 U. Carratelli (CARR) 48 h-post R: 412.21 ± 26.61 U vs. 373.80 ± 36.08 U. CARR)]. There was no change in TAC between the 2 training sessions investigated. In LMI training, OxL significantly decreased in post-training and increased to reach the baseline at 48 h-post R, whereas TAC increased only at 48 h-post R. In HI training, OxL significantly increased to reach a high oxidative stress 48 h-post R, whereas TAC was lower in post-training than pretraining. Conclusion The pattern of OxL and TAC levels implies different regulation mechanisms by HI and LMI training sessions. High oxidative stress induced by an HI protocol might be associated with both insufficient TAC and recovery time at 48 h necessary to restore redox balance.


      PubDate: 2016-04-26T15:24:08Z
       
  • National football promotion in China: Opportunities and challenges in
           public health

    • Abstract: Publication date: Available online 19 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Jincheng Xu, Can Gao, Jiexiu Zhao



      PubDate: 2016-04-21T13:55:07Z
       
  • High-intensity interval training (HIIT) for patients with chronic
           diseases—R1

    • Abstract: Publication date: Available online 12 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Leanna M. Ross, Ryan R. Porter, J. Larry Durstine
      Exercise training provides physiological benefits for both improving athletic performance and for maintaining good health. Different exercise training modalities and strategies exist. Two common exercise strategies are high-intensity interval training (HIIT) and moderate-intensity continuous exercise training (MCT). HIIT was first used early in the 20th century and popularized later that century for improving performance of Olympic athletes. The primary premise underlying HIIT is that, compared to energy expenditure-matched MCT, a greater amount of work is performed at a higher intensity during a single exercise session which is achieved by alternating high-intensity exercise intervals with low-intensity exercise or rest intervals. Emerging research suggests that this same training method can provide beneficial effects for patients with a chronic disease and should be included in the comprehensive medical management plan. Accordingly, a major consideration in developing an individual exercise prescription for a patient with a chronic disease is the selection of an appropriate exercise strategy. In order to maximize exercise training benefits, this strategy should be tailored to the individual's need. The focus of this paper is to provide a brief summary of the current literature regarding the use of HIIT to enhance the functional capacity of individuals with cardiovascular, pulmonary, and diabetes diseases.


      PubDate: 2016-04-16T13:36:34Z
       
  • Effect of aerobic exercise on insulin resistance and central adiposity
           

    • Abstract: Publication date: Available online 8 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Shenglong Le, Lijuan Mao, Dajiang Lu, Yifan Yang, Xiao Tan, Petri Wiklund, Sulin Cheng
      Purpose This study aimed to assess whether the benefits of exercise on central adiposity and insulin resistance (HOMA-IR) are maintained after discontinuation of intervention in the overweight/obese (OWOB) women. Methods The study subjects were from 2 independent studies with similar aerobic exercise (AE) intervention programs. In study I, 15 OWOB postmenopausal women with pre-diabetes (body mass index, BMI = 24–33 kg/m2, aged 52–65 years) completed an 8-month exercise intervention and were followed for 2 years after the intervention. In study II, 12 OWOB (BMI = 25–35 kg/m2, aged 30–50 years) premenopausal women participated in a 6-week AE and were followed for 4 years after the intervention. The exercise program consisted of progressive AE with intensity of 60 to 75% of initial fitness level, 30–60 min/time and 3–5 times/week. Fat mass (FM) was assessed by bioelectrical impedance device (Inbody 720; Study I) or Dual Energy X-ray Absorptiometry (DXA, Prodigy; Study II). Plasma glucose and insulin were assessed by chemiluminescent immunoassay and HOMA-IR was calculated. Results Both 8-month and 6-week moderate AE were effective in reducing HOMA-IR (–18.9%, p = 0.012 and –26.7%, p = 0.046, respectively), 8-month AE reduced FM at upper abdominal region (–6.2%, p = 0.021). However, these improvements did not maintain in either study at the follow-up. Conclusion The aerobic exercise program used in these studies was effective to reduce insulin resistance and/or fat mass in central body region among overweight and obese women. However, when exercise intervention was discontinued, the beneficial effects following both short- and long-term intervention disappeared. Thus maintaining exercise seems to be required if one wants to reap the benefits of exercise in the long-term.


      PubDate: 2016-04-09T09:18:52Z
       
  • Targeting mitochondrial phenotypes for non-communicable diseases

    • Abstract: Publication date: Available online 7 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Zhengtang Qi, Shuzhe Ding
      The concept that “exercise is medicine” has been challenged by the rising prevalence of non-communicable chronic diseases (NCDs). This is partly due to the fact that the underlying mechanisms of how exercise influences energy homeostasis and counteracts high-fat diets and physical inactivity is complex and remains relatively poorly understood on a molecular level. In addition to genetic polymorphisms in humans that lead to gross variations in responsiveness to exercise, adaptation in mitochondrial networks are central to physical activity, inactivity and diet. To harness the benefits of exercise for NCDs, much work still needs to be done to improve health effectively on a societal level such as developing personalized exercise interventions aided by advances in high-throughput genomics, proteomics and metabolomics. We propose that understanding the mitochondrial phenotype according to the molecular information of genotypes, lifestyles and exercise responsiveness in individuals will optimize exercise effects for prevention of NCDs.


      PubDate: 2016-04-09T09:18:52Z
       
  • Exercise is more than medicine: The working age population's wellbeing and
           productivity

    • Abstract: Publication date: Available online 7 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Gisela Sjøgaard, Jeanette Reffstrup Christensen, Just Bendix Justesen, Mike Murray, Tina Dalager, Gitte Fredslund, Karen Søgaard
      Background Physical activity (PA) includes muscle activity during exercise, manual work, and leisure time activities including sport. Conflicting results exist regarding health effects of PA that may deteriorate with manual work and elite sports, but improve when performed in moderation in accordance with international guidelines and may additionally enhance wellbeing and productivity. Methods In Denmark 15 randomized controlled trials have been conducted, introducing exercise at the workplace enrolling > 3 500 workers. The interventions lasted from 10 – 52 weeks and offered ~1 h weekly supervised exercise during working hours according to the concept of intelligent physical exercise training (IPET) that is based on evidenced sports sciences training principles and tailored to work exposure, employee health status, and physical capacity. Questionnaire surveys and health checks including blood and muscle sampling were performed at baseline and follow-up. The job groups included: Office and computer workers, dentists, industrial technicians, cleaning personnel, health care workers, construction workers, and fighter/helicopter pilots. Results In all job groups significant improvements were documented regarding health outcomes. These were job group specific: Neck pain was reduced among office and computer workers, dentists, industrial laboratory technicians, health care workers as well as fighter pilots. Cardio-respiratory fitness—a health risk indicator for cardio-metabolic diseases—was improved among office and computer workers, health care workers, and construction workers. Additionally, other improvements were evidenced such as increased muscle strength and balance control. Importantly, productivity increased with improved muscle strength and decreased body mass index. Conclusions In every study group outcomes of improved health were documented and the effect sizes were of clinical relevance. Thus, IPET does enhance health if a program with evidenced efficacy is implemented by expert trainees with support of the employer. Cost effectiveness estimates indicate acceptable cost relative to savings on health expenses and lost productivity.


      PubDate: 2016-04-09T09:18:52Z
       
  • The role of physical activity and exercise in obesity and weight
           management: time for critical appraisal

    • Abstract: Publication date: Available online 8 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Petri Wiklund
      The prevalence of overweight and obesity has increased dramatically during the last three decades with devastating consequences to public health. Recommended strategies to reduce obesity have focused on healthier diet and physical activity. Clearly, these approaches have not been successful, but whether this is due failure to restrict energy intake or to maintain high levels of energy expenditure has been the subject of great controversy. Consequently, there has been a great deal of confusion about the role of physical activity and exercise in obesity and weight management. In this article, the theoretical basis for considering reduced physical activity and energy expenditure as the cause of obesity is appraised. Further, the role of physical activity in food intake and weight control is examined. The idea that obesity is caused by consistent decline in daily energy expenditure is not supported either by objective measures of energy expenditure or physiological theory of weight gain alone. However, since voluntary exercise is the most important discretionary component of total daily energy expenditure, it can affect energy balance. Therefore, physical activity and exercise hold potential as part of the solution for the ongoing obesity epidemic.


      PubDate: 2016-04-09T09:18:52Z
       
  • Physical activity, sedentary behavior and long term cardiovascular risk in
           young people: A review and discussion of methodology in prospective
           studies

    • Abstract: Publication date: Available online 1 April 2016
      Source:Journal of Sport and Health Science
      Author(s): Jakob Tarp, Jan Christian Brønd, Lars Bo Andersen, Niels Christian Møller, Karsten Froberg, Anders Grøntved
      The long-term effects of physical activity or sedentary behavior on cardiovascular health in young people are not well understood. In this study, we use a narrative format to review the evidence for a prospective association with adiposity and other well-established biological cardiovascular risk factors in healthy young people, considering only studies with at least 2 years of follow-up. Physical activity appears to elicit a long-term beneficial effect on adiposity and particularly markers of cardiovascular health. With adiposity, however, a few studies also reported that higher levels of physical activity were associated with higher levels of adiposity. Time spent sedentary does not appear to be related to adiposity or markers of cardiovascular health independent of physical activity. We then discuss the uncertainties in the underlying causal chain and considered a number of alternative modeling strategies, which could improve our understanding of the relationship in future studies. Finally, we consider the current methodology for assessing physical activity and sedentary time.


      PubDate: 2016-04-06T09:09:53Z
       
  • Exercise for health: Serious fun for the whole person?

    • Abstract: Publication date: Available online 30 March 2016
      Source:Journal of Sport and Health Science
      Author(s): Mark Stephen Nesti
      The suggestion that exercise can be viewed as medicine (Chen, 2012) 1 sounds a very appealing idea. In this paper an alternative view will be presented which argues that although the statement, exercise is medicine, makes sense biologically and physiologically speaking, it is more problematic from a behavioral perspective. Inactivity and declining levels of exercise in most countries in the developed world has been identified in studies, policy documents and reports throughout the last few decades. Efforts at turning this trend around by encouraging more people to exercise appear to be failing with few exceptions. Although there are numerous possible reasons behind this finding, I will propose that one of the most important is that for many, exercise is seen as hard work, unenjoyable and only concerned with physical fitness. In contrast, there is ample evidence that sport activity, at least for the vast majority who play for fun, is intrinsically motivating and can provide psychological, social and spiritual benefits in addition to physical. The arguments discussed in this paper for a greater emphasis on sport for health rather than exercise draw mainly on psychological theory. Focus is on those strands of the discipline that have been referred to as holistic, such as existential, humanistic and phenomenological perspectives.


      PubDate: 2016-04-01T09:03:45Z
       
  • “Physical activity continuum throughout the lifespan: is exercise
           medicine or what?”

    • Abstract: Publication date: Available online 31 March 2016
      Source:Journal of Sport and Health Science
      Author(s): Sulin Cheng, Lijuan Mao



      PubDate: 2016-04-01T09:03:45Z
       
  • Empowering youth sport environments: implications for daily
           moderate-to-vigorous physical activity and adiposity

    • Abstract: Publication date: Available online 31 March 2016
      Source:Journal of Sport and Health Science
      Author(s): Sally A.M. Fenton, Joan L. Duda, Paul R. Appleton, Timothy G. Barrett
      Background Evidence suggests involvement in youth sport does not guarantee daily guidelines for moderate-to-vigorous physical activity (MVPA) are met, and participation may not mitigate the risks associated with physical inactivity. The need to promote higher habitual MVPA engagement among children active in the youth sport context has therefore been underlined. Framed by self-determination theory, the aim of the present study was to examine the implications of the motivational climate created in youth sport, for children's daily engagement in MVPA and associated adiposity. Specifically, we sought to test a motivational sequence in which children's perceptions of an empowering coach-created motivational climate were related to autonomous and controlled motivation, which in turn predicted sport-related enjoyment. Finally, enjoyment is assumed to predict accelerometer assessed daily MVPA and, following this, adiposity Method Male and female youth sport participants aged 9-16 years (N = 112) completed multi-section questionnaires assessing their perceptions of the motivational climate created in youth sport (i.e., autonomy supportive, task involving, socially supportive), autonomous and controlled motivation, and sport-related enjoyment. Daily MVPA engagement was determined via 7 days of accelerometry. Percent body fat (BF%) was estimated using bio-electrical impedance analysis. Results Path analysis revealed perceptions of an empowering motivational climate positively predicted players' autonomous motivation, and in turn, sport-related enjoyment. Enjoyment was also significantly negatively related to players' BF%, via a positive association with daily MVPA. Conclusion Fostering more empowering youth sport environments may hold implications for the prevention of excess adiposity, through encouraging higher habitual MVPA engagement. Findings may inform the optimal design of youth sport settings for MVPA promotion, and contribute towards associated healthy weight maintenance among youth active in this context. Longitudinal and intervention studies are required to confirm these results.


      PubDate: 2016-04-01T09:03:45Z
       
  • Exercise is recreation not medicine

    • Abstract: Publication date: Available online 30 March 2016
      Source:Journal of Sport and Health Science
      Author(s): Andy Smith
      Purpose This paper responds to the question, is exercise medicine? It does so using a qualitative case study that proposes that exercise is recreation. The study (1) describes and reflects upon an exercise is recreation metaphor (2) establishes the principles and processes used to develop a sport park within which exercise is recreation and (3) presents a comparative analysis of the exercise is recreation approach with a UK quality framework for exercise referrals. Methods Four years of documentation were collated and placed into the 14 categories (1) university strategies; (2) plans of the site (3) policy documents; (4) minutes of a steering group (5) contemporary documents; (6) organisational charts; (7) responses to local government policies on sport; (8) consultation documents; (9) operational procedures; (10) facility specifications; (11) partnership agreements; (12) material relating to the university's work on events, (13) notes on the universities sport department and (14) timetables. These data were analysed through a four stage process which used recreation as the analytical theme for a comparative analysis. Results The characteristics of the exercise is recreation metaphor in this case are (1) a focus on the experience of the user; (2) the promotion of wellbeing; (3) the importance of community; (4) embracing inclusivity; (5) sport; (6) aesthetics and (7) leisure time. The principles and processes used to develop the sport park were (1) custodianship; (2) partnerships; (3) values; (4) inter-professional working; (5) local heritage; (6) change; (7) the natural park environment and (8) ‘riding the bike as you build it’. The comparative analysis with a UK quality framework for ‘exercise referrals’ clearly shows a difference from an exercise is recreation approach. Conclusion Exercise is recreation and may enable individuals and communities to reach a state of wellbeing.


      PubDate: 2016-04-01T09:03:45Z
       
  • Performance on the Functional Movement Screen in older active adults

    • Abstract: Publication date: March 2016
      Source:Journal of Sport and Health Science, Volume 5, Issue 1
      Author(s): Ulrike H. Mitchell, A. Wayne Johnson, Pat R. Vehrs, J. Brent Feland, Sterling C. Hilton
      Background The Functional Movement Screen (FMS™) has become increasingly popular for identifying functional limitations in basic functional movements. This exploratory and descriptive study was undertaken to confirm feasibility of performing the FMS™ in older active adults, assess prevalence of asymmetries and to evaluate the relationship between functional movement ability, age, physical activity levels and body mass index (BMI). Methods This is an observational study; 97 men (n = 53) and women (n = 44) between the ages of 52 and 83 participated. BMI was computed and self-reported physical activity levels were obtained. Subjects were grouped by age (5-year intervals), BMI (normal, over-weight, and obese) and sex. Each participant's performance on the FMS™ was digitally recorded for later analysis. Results The youngest age group (50–54 years) scored highest in all seven tests and the oldest age group (75+) scored lowest in most of the tests compared to all other age groups. The subjects in the “normal weight” group performed no different than those who were in the “overweight” group; both groups performed better than the “obese” group. Of the 97 participants 54 had at least one asymmetry. The pairwise correlations between the total FMS™ score and age (r = −0.531), BMI (r = −0.270), and the measure of activity level (r = 0.287) were significant (p < 0.01 for all). Conclusion FMS™ scores decline with increased BMI, increased age, and decreased activity level. The screen identifies range of motion- and strength-related asymmetries. The FMS™ can be used to assess functional limitations and asymmetries. Future research should evaluate if a higher total FMS™ score is related to fewer falls or injuries in the older population.


      PubDate: 2016-03-17T08:50:33Z
       
  • Intermittent blood flow restriction does not reduce atrophy following
           anterior cruciate ligament reconstruction

    • Abstract: Publication date: March 2016
      Source:Journal of Sport and Health Science, Volume 5, Issue 1
      Author(s): Erik Iversen, Vibeke Røstad, Arne Larmo
      Background A previous study has reported a 50% reduction in disuse atrophy of the quadriceps during the first 14 days after anterior cruciate ligament (ACL) reconstruction. A follow-up trial is needed to confirm these promising results. The present study aims to investigate the effect of an occlusion stimulus on quadriceps atrophy after ACL reconstruction. Methods A total of 24 subjects participated in the study. They were randomized into two groups. Starting the 2nd day after surgery, the occlusion group received an occlusion stimulus for 5 min, followed by removal of the occlusive pressure for 3 min. This was repeated five times in one training session, twice daily. During the period of occlusive stimulus, the subjects performed 20 low load exercises for the quadriceps. The control group followed the same exercise protocol, but without the occlusion stimulus. Changes in quadriceps anatomical cross section area (ACSA) were measured using axial magnetic resonance (MR) images at 40% and 50% of the length of the femur. Results Both groups had a significant reduction of quadriceps ACSA from 2 days before surgery to 16 days after surgery. During the intervention period, the occlusion group lost 13.8% ± 1.1% (mean ± SEM) and the control group lost 13.1% ± 1.0% of their quadriceps ACSA, respectively. There was no significant difference between the occlusion and control groups with regards to atrophy of the quadriceps muscles. Conclusion In conflict with other studies using a similar protocol, application of blood flow restriction the first 14 days after ACL reconstruction did not reduce quadriceps ACSA muscle atrophy measured by MR in a population of athletes.


      PubDate: 2016-03-17T08:50:33Z
       
  • Single dose of intra-muscular platelet rich plasma reverses the increase
           in plasma iron levels in exercise-induced muscle damage: A pilot study

    • Abstract: Publication date: March 2016
      Source:Journal of Sport and Health Science, Volume 5, Issue 1
      Author(s): Zekine Punduk, Onur Oral, Nadir Ozkayin, Khalid Rahman, Rana Varol
      Background Platelet rich plasma (PRP) therapy is widely used in enhancing the recovery of skeletal muscle from injury. However, the impact of intramuscular delivery of PRP on hematologic and biochemical responses has not been fully elucidated in exercise-induced muscle damage. The purpose of this investigation the effects of intramuscular delivery of PRP on hematologic and biochemical responses and recovery strategy muscle damage induced by high intensity muscle exercise (exercise-induced muscle damage, EIMD). Methods Moderately active male volunteers participated in this study and were assigned to a control group (control, n = 6) and PRP administration group (PRP, n = 6). The subjects performed exercise with a load of 80% one repetition maximum (1RM) maximal voluntary contraction of the elbow flexors until point of exhaustion of the non-dominant arm was reached. The arms were treated with saline or autologous PRP post-24 h EIMD. Venous blood samples were obtained in the morning to establish a baseline value and 1–4 days post-exercise and were analyzed for serum ferritin, iron, iron binding capacity (IBC), creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Results The baseline levels of plasma iron, ferritin, IBC, CK, LDH, AST, and ALT were similar in both the control and PRP groups. However, 24-h following exercise a significant increase in these parameters was observed in both groups between 1 and 4 days during the recovery period. Interestingly, PRP administration decreased plasma iron levels compared to the control on the second day post-exercise. Plasma IBC increased in PRP group from Days 2 to 4 post-exercise compared to the control group whilst PRP administration had no effect on plasma ferritin, CK, AST, ALT, or LDH. Conclusion Acute exhaustive exercise increased muscle damage markers, including plasma iron, IBC, and ferritin levels, indicating muscle damage induced by exercise. PRP administration improves inflammation by reversing the increase in the iron levels post-exercise without displaying any myotoxicity and may have a role to play in the recovery of exercise-induced muscle damage.


      PubDate: 2016-03-17T08:50:33Z
       
  • The use of the greater trochanter marker in the thigh segment model:
           Implications for hip and knee frontal and transverse plane motion

    • Abstract: Publication date: March 2016
      Source:Journal of Sport and Health Science, Volume 5, Issue 1
      Author(s): Valentina Graci, Gretchen B. Salsich
      Background The greater trochanter marker is commonly used in 3-dimensional (3D) models; however, its influence on hip and knee kinematics during gait is unclear. Understanding the influence of the greater trochanter marker is important when quantifying frontal and transverse plane hip and knee kinematics, parameters which are particularly relevant to investigate in individuals with conditions such as patellofemoral pain, knee osteoarthritis, anterior cruciate ligament (ACL) injury, and hip pain. The aim of this study was to evaluate the effect of including the greater trochanter in the construction of the thigh segment on hip and knee kinematics during gait. Methods 3D kinematics were collected in 19 healthy subjects during walking using a surface marker system. Hip and knee angles were compared across two thigh segment definitions (with and without greater trochanter) at two time points during stance: peak knee flexion (PKF) and minimum knee flexion (MinKF). Results Hip and knee angles differed in magnitude and direction in the transverse plane at both time points. In the thigh model with the greater trochanter the hip was more externally rotated than in the thigh model without the greater trochanter (PKF: −9.34° ± 5.21° vs. 1.40° ± 5.22°, MinKF: −5.68° ± 4.24° vs. 5.01° ± 4.86°; p < 0.001). In the thigh model with the greater trochanter, the knee angle was more internally rotated compared to the knee angle calculated using the thigh definition without the greater trochanter (PKF: 14.67° ± 6.78° vs. 4.33° ± 4.18°, MinKF: 10.54° ± 6.71° vs. −0.01° ± 2.69°; p < 0.001). Small but significant differences were detected in the sagittal and frontal plane angles at both time points (p < 0.001). Conclusion Hip and knee kinematics differed across different segment definitions including or excluding the greater trochanter marker, especially in the transverse plane. Therefore when considering whether to include the greater trochanter in the thigh segment model when using a surface markers to calculate 3D kinematics for movement assessment, it is important to have a clear understanding of the effect of different marker sets and segment models in use.


      PubDate: 2016-03-17T08:50:33Z
       
  • Commentary on: “Assessing proprioception: A critical review of
           methods” by Han et al.

    • Abstract: Publication date: March 2016
      Source:Journal of Sport and Health Science, Volume 5, Issue 1
      Author(s): Carmen Krewer, Ann Van de Winckel, Naveen Elangovan, Joshua E. Aman, Jürgen Konczak



      PubDate: 2016-03-17T08:50:33Z
       
  • Assessing proprioception: What do you really want to
           know?—Response to Krewer et al.

    • Abstract: Publication date: March 2016
      Source:Journal of Sport and Health Science, Volume 5, Issue 1
      Author(s): Jia Han, Gordon Waddington, Roger Adams, Judith Anson, Yu Liu



      PubDate: 2016-03-17T08:50:33Z
       
  • Editorial board

    • Abstract: Publication date: March 2016
      Source:Journal of Sport and Health Science, Volume 5, Issue 1




      PubDate: 2016-03-17T08:50:33Z
       
  • Assessing proprioception: A critical review of methods

    • Abstract: Publication date: March 2016
      Source:Journal of Sport and Health Science, Volume 5, Issue 1
      Author(s): Jia Han, Gordon Waddington, Roger Adams, Judith Anson, Yu Liu
      To control movement, the brain has to integrate proprioceptive information from a variety of mechanoreceptors. The role of proprioception in daily activities, exercise, and sports has been extensively investigated, using different techniques, yet the proprioceptive mechanisms underlying human movement control are still unclear. In the current work we have reviewed understanding of proprioception and the three testing methods: threshold to detection of passive motion, joint position reproduction, and active movement extent discrimination, all of which have been used for assessing proprioception. The origin of the methods, the different testing apparatus, and the procedures and protocols used in each approach are compared and discussed. Recommendations are made for choosing an appropriate technique when assessing proprioceptive mechanisms in different contexts.


      PubDate: 2016-03-17T08:50:33Z
       
  • The epistemic basis of distance running injury research: A historical
           perspective

    • Abstract: Publication date: Available online 11 March 2016
      Source:Journal of Sport and Health Science
      Author(s): Adam Hulme, Caroline F. Finch



      PubDate: 2016-03-12T16:15:08Z
       
  • The problem with running injuries

    • Abstract: Publication date: Available online 8 March 2016
      Source:Journal of Sport and Health Science
      Author(s): Walter Herzog



      PubDate: 2016-03-12T16:15:08Z
       
  • Effects of Tai Ji Quan training on gait kinematics in older Chinese women
           with knee osteoarthritis: A randomized controlled trial

    • Abstract: Publication date: Available online 15 February 2016
      Source:Journal of Sport and Health Science
      Author(s): Qingguang Zhu, Lingyan Huang, Xie Wu, Lin Wang, Yunya Zhang, Min Fang, Yu Liu, Jing Xian Li
      Background Although Tai Ji Quan has been shown to relieve pain and improve functional mobility in people with knee osteoarthritis (OA), little is known about its potential benefits on gait characteristics among older Chinese women who have a high prevalence of both radiographic and symptomatic knee OA. This study aims to assess the efficacy of a tailored Tai Ji Quan intervention on gait kinematics for older Chinese women with knee OA. Methods A randomized controlled trial involving 46 older women in Shanghai, China, with clinically diagnosed knee OA. Randomized (1:1) participants received either a 60-min Tai Ji Quan session (n = 23) three times weekly or a 60-min bi-weekly educational session (n = 23) for 24 weeks. Primary outcomes were change in gait kinematic measures from baseline to 24 weeks. Secondary outcomes included changes in scores on the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Short Physical Performance Battery (SPPB). Results After 24 weeks the Tai Ji Quan group demonstrated better performance in gait velocity (mean difference, 8.40 cm/s, p = 0.01), step length (mean difference, 3.52 cm, p = 0.004), initial contact angle (mean difference, 2.19°, p = 0.01) and maximal angle (mean difference, 2.61°, p = 0.003) of flexed knees during stance phase compared to the control group. In addition, the Tai Ji Quan group showed significant improvement in WOMAC scores (p < 0.01) (mean difference, -4.22 points in pain, p = 0.002; -2.41 points in stiffness, p <0.001; -11.04 points in physical function, p = 0.006) and SPPB scores (mean difference, 1.22 points, p < 0.001). Conclusion Among older Chinese women with knee OA, a tailored Tai Ji Quan intervention improved gait outcomes. The intervention also improved overall function as indexed by the WOMAC and SPPB. These results support the use of Tai Ji Quan for older Chinese adults with knee OA to both improve their functional mobility and reduce pain symptomology.


      PubDate: 2016-02-17T08:40:19Z
       
  • The public health benefits of Tai Ji Quan—Addressing the unmet needs
           of aging populations in the 21st century

    • Abstract: Publication date: Available online 2 February 2016
      Source:Journal of Sport and Health Science
      Author(s): Fuzhong Li



      PubDate: 2016-02-12T16:09:05Z
       
  • The effect of fatigue and duration knowledge of exercise on kicking
           performance in soccer players

    • Abstract: Publication date: Available online 2 February 2016
      Source:Journal of Sport and Health Science
      Author(s): Ricardo Manuel Pires Ferraz, Roland van den Tillaar, Ana Pereira, Mário C. Marques
      Purpose The purpose of this study was to investigate the influence of fatigue upon kicking maximal ball velocity and the target-hitting accuracy of soccer players; and also to examine the effect of the knowledge of the exercise duration upon these two parameters. Methods Twenty-four semi-professional soccer players participated in this study and performed maximal instep kicks before and after the implementation of an exercise protocol, either with or without knowledge of the duration of this protocol. Results A mixed model of analysis of variance showed that kicking maximal ball velocity was significantly affected (F(5, 85) = 11.6; p < 0.001; η2 = 0.39) but only after just one circuit of the fatigue protocol and then remained similar. Accuracy did not change during the protocol (F(5, 75) = 0.23; p = 0.76; η2 = 0.03) and knowing the duration of exercitation did not affect accuracy and velocity development (F(1, 23) ≤ 1.04; p ≥ 0.32; η2 ≤ 0.06). Conclusion These findings demonstrated the potential negative effects of fatigue on kicking ball velocity in soccer but not in the kicking accuracy and that the effect of fatigue may not be progressive over time. Knowing or not knowing the duration of exercitation did not affect the results.


      PubDate: 2016-02-12T16:09:05Z
       
  • Considerations when using the activPAL monitor in field based research
           with adult populations

    • Abstract: Publication date: Available online 3 February 2016
      Source:Journal of Sport and Health Science
      Author(s): Charlotte L. Edwardson, Elisabeth A.H. Winkler, Danielle H. Bodicoat, Tom Yates, Melanie J. Davies, David W. Dunstan, Genevieve N. Healy
      Research indicates that high levels of sedentary behaviour (sitting or lying with low energy expenditure) are adversely associated with health. A key factor in improving our understanding of the impact of sedentary behaviour (and patterns of sedentary time accumulation) on health is the use of objective measurement tools that collect date and time-stamped activity information. One such tool is the activPAL monitor. This thigh-worn device uses accelerometer-derived information about thigh position to determine the start and end of each period spent sitting/lying, standing and stepping, as well as stepping speed, step counts and postural transitions. The activPAL is increasingly being used within field-based research for its ability to measure sitting/lying via posture. We summarise key issues to consider when using the activPAL in physical activity and sedentary behaviour field-based research with adult populations. It is intended that the findings and discussion points be informative for researchers who are currently using activPAL monitors or are intending to use them. Pre-data collection decisions, monitor preparation and distribution, data collection considerations, and manual and automated data processing possibilities are presented using examples from current literature and experiences from two research groups from the UK and Australia.


      PubDate: 2016-02-12T16:09:05Z
       
  • Neighborhood environment, physical activity, and quality of life in
           adults: Intermediary effects of personal and psychosocial factors

    • Abstract: Publication date: Available online 25 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Eleni Theodoropoulou, Nektarios Stavrou, Konstantinos Karteroliotis
      Background Studies have indicated that there is a positive and indirect relationship between physical activity (PA) and quality of life (QoL). The current study examined this relationship through a social cognitive model with consideration to the intermediary effects of exercise self-efficacy, and physical (PCS) and psychological (MCS) health. Additionally, this model was widened to include concepts from the ecological theory, and any causal associations among neighborhood environment, PA, and QoL. Methods Six hundred and eighty four physically active adults (39.16 ± 13.52 years, mean ± SD), living in Athens, Greece, completed a series of questionnaires measuring PA, QoL, exercise self-efficacy, PCS, MCS, neighborhood environment, and family and friend support for PA. The examined models were analyzed using structural equation modeling. Results The social cognitive and ecological models proved to be of appropriate fit. Within the social cognitive model, PA positively affected QoL through the mediating effects of exercise self-efficacy, PCS, and MCS. With regards to the ecological model, neighborhood environment positively influenced QoL through the intermediary effects of family support for PA, exercise self-efficacy, PA, PCS, and MCS. Conclusion Results indicated that the most important mediators in the examined models were exercise self-efficacy and health. Further, findings demonstrated the role of neighborhood environment in enhancing PA and QoL. Future studies should be carried out applying longitudinal data for a better understanding of these associations over time.


      PubDate: 2016-02-01T17:44:13Z
       
  • Preparatory training at tenuates drastic response of the insulin-like
           growth factor binding protein 1 at the point of maximal oxygen consumption
           in handball players

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Olgica Nedić, Miloš Šunderić, Goran Miljuš, Zoran Valdevit, Vladimir Jakovljević, Marija Glibetić, Vesna Vučić
      Background Intensive exercise changes physiological need for glucose and several biochemical pathways responsible for its metabolism response. Among them are those which involve insulin, insulin-like growth factor (IGF)-I, and IGF-binding proteins (IGFBPs). Different types and degrees of exercise, as well as an athlete's fitness, may induce a range of responses regarding concentrations and time needed for the alteration. The idea of the work was to find out whether and how insulin/IGF axis responds to additional physical activity in the already trained subjects and if so, is the adaptation potentially beneficial from the aspect of metabolic control. Methods The effect of 4-week intensive training on campus (preparatory training) on the levels of insulin, IGF-I, and IGFBPs during maximal progressive exercise test (MPET) on a treadmill was compared to the results obtained during MPET conducted after a regular training season of a female elite handball team (n = 17, age 17 ± 1 years old, height 171 ± 8 cm, weight 65 ± 8 kg and BMI 22 ± 1 kg/m2 at the beginning of the study; there were no significant changes at the end). Serum samples were obtained from players immediately before the test (basal), at the end of the test after reaching the point of maximal oxygen consumption (VO2max), and after recovery. Results The concentration of insulin decreased at VO2max, but remained higher in players after preparatory training (12.2 ± 2.5 vs. 8.9 ± 4.4 mU/L, p = 0.049). The level of IGFBP-1 decreased in players at VO2max in either case of training, but it remained much higher in tests performed after the preparatory regime (1.4 ± 0.5 densitometric units) than before (0.7 ± 0.3 densitometric units, p = 0.029). Concentrations of IGF-I, IGFBP-2, -3, and -4 did not change significantly. Conclusion As intensive physical activity requires efficient energy supply, it seemed relevant to investigate changes of the metabolic hormones responsible for glucose control during MPET which can be compared (in terms of the exercise overload) with the episodes of very intensive games. The inverse relation between insulin and IGFBP-1 was lost during MPET, as these two molecules changed in the same direction. The results obtained suggest less severe stress-induced depression of insulin and IGFBP-1 after preparatory training. But another metabolic mechanism cannot be excluded, and that is potentially impaired insulin sensitivity resulting in higher level of IGFBP-1. Taking into account both possible explanations, the changes seen cannot be, at the moment, defined as either beneficial or not for athletes' glucose control.


      PubDate: 2016-01-25T13:26:03Z
       
  • Multiscale entropy: a tool for understanding the complexity of postural
           control

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Michael A. Busa, Richard E.A. van Emmerik
      Clinical disorders often are characterized by a breakdown in dynamical processes that contribute to the control of upright standing. Disruption to a large number of physiological processes operating at different time scales can lead to alterations in postural center of pressure (COP) fluctuations. Multiscale entropy (MSE) has been used to identify differences in fluctuations of postural COP time series between groups with and without known physiological impairments at multiple time scales. The purpose of this paper is to: 1) review basic elements and current developments in entropy techniques used to assess physiological complexity; and 2) identify how MSE can provide insights into the complexity of physiological systems operating at multiple time scales that underly the control of posture. We review and synthesize evidence from the literature providing support for MSE as a valuable tool to evaluate the breakdown in the physiological processes that accompany changes due to aging and disease in postural control. This evidence emerges from observed lower MSE values in individuals with multiple sclerosis, idiopathic scoliosis, and in older individuals with sensory impairments. Finally, we suggest some future applications of MSE that will allow for further insight into how physiological deficits impact the complexity of postural fluctuations; this information may improve the development and evaluation of new therapeutic interventions.


      PubDate: 2016-01-25T13:26:03Z
       
  • p &lt; 0.05, &lt; 0.01, &lt; 0.001, &lt; 0.0001, &lt;
           0.00001, &lt; 0.000001, or &lt; 0.0000001 …

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Weimo Zhu



      PubDate: 2016-01-25T13:26:03Z
       
  • Time-dependent gene expression analysis after mouse skeletal muscle
           contusion

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Weihua Xiao, Yu Liu, Beibei Luo, Linlin Zhao, Xiaoguang Liu, Zhigang Zeng, Peijie Chen
      Background Though the mechanisms of skeletal muscle regeneration are deeply understood, those involved in muscle contusion, one of the most common muscle injuries in sports medicine clinics, are not.The objective of this study is to explore the mechanisms involved in muscle regeneration after contusion injury. Methods In this study, a total of 72 mice were used. Eight of them were randomly chosen for the control group, while the rest were subjected to muscle contusion. Subsequently, their gastrocnemius muscles were harvested at different time points. The changes in muscle morphology were assessed by hematoxylin and eosin (HE) stain.In addition, the gene expression was analyzed by real-time polymerase chain reaction. Results The data showed that the expression of many genes, i.e., specific markers of immune cells and satellite cells, regulatory factors for muscle regeneration, cytokines, and chemokines, increased in the early stages of recovery, especially in the first three days. Furthermore, there were strict rules in the expression of these genes. However, almost all the genes returned to normal at 14 days post-injury. Conclusion These data suggest that the sequence of immune cells invaded after muscle contusion was neutrophils, M1 macrophages and M2 macrophages. Some CC (CCL2, CCL3, and CCL4) and CXC (CXCL10) chemokines may be involved in the chemotaxis of these immune cells. HGF may be the primary factor to activate the satellite cells after muscle contusion. Moreover,2 weeks is needed to recover when acute contusion happens as used in this study.


      PubDate: 2016-01-25T13:26:03Z
       
  • The effects of total soy saponins on free radicals in the quadriceps
           femoris, serum testosterone, LDH, and BUN of exhausted rats

    • Abstract: Publication date: Available online 22 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Zhigang Liu, Ruixin Nie, Yun Liu, Zhouhong Li, Chenxi Yang, Zhengying Xiong
      Purpose The aim of this study was to investigate the impact of total soy saponins (TS) on the free radical metabolism from the quadriceps femoris muscle, serum testosterone, lactate dehydrogenase (LDH) , and blood urea nitrogen (BUN) in rats exercised to exhaustion. Methods A one-time exhausted treadmill exercise session was used. Sprague-Dawley rats were divided into four groups: a control group—animals receiving no TS and no exercise (NTSNE) , animals receiving TS and no exercise group (TSNE) , animals receiving no TS and exercised to exhaustion group (NTSE) , and animals receiving TS and exercised to exhaustion group (TSE) . The TSNE and TSE groups were fed TS at a dosage of 20 mg/kg body weight once per day for 2 weeks. The NTSE group was given a placebo, and the NTSNE group was not given any treatment. The NTSE and TSE groups were exercised at speed of 30m/min on treadmill until exhausted. The exercise time and exercise distance were recorded when the rats became exhausted and the rats were then decapitated and anatomized immediately. A 10% homogenate of the quadriceps femoris tissue was prepared. The levels of superoxide dismutase (SOD) , catalase (CAT) , malondialdehyde (MDA) , glutathione peroxidase (GSH-Px) , glutathione reductase (GR) , reduced glutathione (GSH) , total antioxidant capacity (T-AOC) , LDH, BUN, and serum testosterone levels were tested. Results TS significantly increased the exercise time by 20.62% (p < 0.05) . The MDA levels were decreased significantly in the TSNE group than in NTSNE group (p < 0.05) , the T-AOC levels increased significantly in the TSNE group than the other three groups (p < 0.01, p < 0.05, p < 0.05) . The LDH activity significantly increased in the NTSE group than in TSNE group (p < 0.05) . The BUN levels significantly increased in the NTSE group than in the other three groups (p < 0.01, p < 0.01, p < 0.05) . The serum testosterone levels increased significantly in the TSNE group than the other three groups (p < 0.01) . SOD, CAT, GSH-Px, GR, and GSH were not statistically different among the groups. Conclusion TS can significantly improve the exercised rat's serum testosterone levels and antioxidant activity in their quadriceps femoris to varying degrees, decrease MDA and serum LDH and BUN levels, increase the exercise time, and delay the occurrence of the fatigue.


      PubDate: 2016-01-25T13:26:03Z
       
  • Confirmatory factor analysis of the VISA-p scale and measurement
           invariance across sexes in athletes with patellar tendinopathy

    • Abstract: Publication date: Available online 22 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Sergio Hernandez-Sanchez, Ferran Abat, María D. Hidalgo, Antonio I. Cuesta-Vargas, Victor Segarra, Jose M. Sanchez-Ibañez, Antonia Gomez-Conesa
      Purpose The Victorian Institute of Sport Assessment-Patella Scale (VISA-P) is the most condition-specific patient-reported outcome measure used to assess symptom severity in athletes with patellar tendinopathy. Previous exploratory factor analyses have been conducted to evaluate the scale's dimensionality, with inconsistent results, and the factor structure of the scale remains unclear. The aims of the present study were to determine the factorial structure of the VISA-Pusing confirmatory factor analysis (CFA) and test measurement invariance across sexes. Methods The study included a convenience sample of 249 Spanish athletes with patellar tendinopathy. CFA was performed to assess factorial validity. Hypothesized 1- and 2-factor models were tested. Measurement invariance across sexes was evaluated via multi-group CFA with several fit indices, using EQS 6.1 software. Results The internal consistency coefficient was 0.74. Several CFA models were examined and the 1-factor model in which errors for items 7 and 8 were correlated, showed acceptable fit in terms of comparative fit index (CFI) and goodness-of-fit index (GFI) statistics (CFI = 0.93; GFI = 0.94; standardized root mean square residual = 0.06; root mean square error of approximation = 0.10; 90% confidence interval = 0.08–0.13). This model was invariant across sexes. Conclusion The 1-factor model of the Spanish version of the VISA-P (VISA-P-Sp) in which errors for items 7 and 8 were correlated demonstrated relative fit in CFA. Scores obtained via VISA-P-Sp can be compared between men and women without sex bias. Further studies should examine the VISA-P and other single-score patient-reported outcome measures concurrently.


      PubDate: 2016-01-25T13:26:03Z
       
  • Multi-scale interactions in interpersonal coordination

    • Abstract: Publication date: Available online 21 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Tehran J. Davis, Thomas R. Brooks, James A. Dixon
      Background Interpersonal coordination is an essential aspect of daily life, and crucial to performance in cooperative and competitive team sports. While empirical research has investigated interpersonal coordination using a wide variety of analytical tools and frameworks, to date very few studies have employed multifractal techniques to study the nature of interpersonal coordination across multiple spatiotemporal scales. In the present study we address this gap. Methods We investigated the dynamics of a simple dyadic interpersonal coordination task where each participant manually controlled a virtual object in relation to that of his or her partner. We tested whether the resulting hand-movement time series exhibits multi-scale properties and whether those properties are associated with successful performance. Results Using the formalism of multifractals, we show that the performance on the coordination task is strongly multi-scale, and that the multi-scale properties appear to arise from interaction-dominant dynamics. Further, we find that the measure of across-scale interactions, multifractal spectrum width, predicts successful performance at the level of the dyad. Conclusion The results are discussed with respect to the implications of multifractals and interaction-dominance for understanding control in an interpersonal context.


      PubDate: 2016-01-25T13:26:03Z
       
  • Comparing dynamical systems concepts and techniques for biomechanical
           analysis

    • Abstract: Publication date: Available online 18 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Richard E.A. van Emmerik, Scott W. Ducharme, Avelino Amado, Joseph Hamill
      Traditional biomechanical analyses of human movement are generally derived from linear mathematics. While these methods can be useful in many situations, they do not describe behaviors in human systems that are predominately nonlinear. For this reason, nonlinear analysis methods based on a dynamical systems approach have become more prevalent in recent literature. These analysis techniques have provided new insights into how systems (1) maintain pattern stability, (2) transition into new states, and (3) are governed by short and long-term (fractal) correlational processes at different spatio-temporal scales. These different aspects of system dynamics are typically investigated using concepts related to variability, stability, complexity, and adaptability. The purpose of this paper is to compare and contrast these different concepts and demonstrate that, although related, these terms represent fundamentally different aspects of system dynamics. In particular, we argue that variability should not uniformly be equated with stability or complexity of movement. In addition, current dynamic stability measures based on nonlinear analysis methods (such as the finite maximal Lyapunov exponent) can reveal local instabilities in movement dynamics, but the degree to which these local instabilities relate to global postural and gait stability and the ability to resist external perturbations remains to be explored. Finally, systematic studies are needed to relate observed reductions in complexity with aging and disease to the adaptive capabilities of the movement system and how complexity changes as a function of different task constraints.


      PubDate: 2016-01-20T13:11:51Z
       
  • Can coordination variability identify performance factors and skill level
           in competitive sport? The case of race walking

    • Abstract: Publication date: Available online 13 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Dario Cazzola, Gaspare Pavei, Ezio Preatoni
      Background Marginal changes in the execution of competitive sports movements can represent a significant change for performance success. However, such differences may emerge only at certain execution intensities and are not easily detectable through conventional biomechanical techniques. This study aimed to investigate if and how competition standard and progression speed affect race walking kinematics from both a conventional and a coordination variability perspective. Methods Fifteen experienced athletes divided into three groups (Elite, International, and National) were studied while race walking on a treadmill at two different speeds (12.0 and 15.5 km/h). Basic gait parameters, the angular displacement of the pelvis and lower limbs, and the variability in continuous relative phase between six different joint couplings were analyzed. Results Most of the spatio-temporal, kinematic, and coordination variability measures proved sensitive to the change in speed. Conversely, non-linear dynamics measures highlighted differences between athletes of different competition standard when conventional analytical tools were not able to discriminate between different skill levels. Continuous relative phase variability was higher for National level athletes than International and Elite in two couplings (pelvis obliquity—hip flex/extension and pelvis rotation—ankle dorsi/plantarflexion) and gait phases (early stance for the first coupling, propulsive phase for the second) that are deemed fundamental for correct technique and performance. Conclusion Measures of coordination variability showed to be a more sensitive tool for the fine detection of skill-dependent factors in competitive race walking, and showed good potential for being integrated in the assessment and monitoring of sports motor abilities.


      PubDate: 2016-01-15T20:48:41Z
       
  • Heart rate variability to assess ventilatory thresholds in professional
           basketball players

    • Abstract: Publication date: Available online 12 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Domingo Jesús Ramos-Campo, Jacobo A. Rubio-Arias, Vicente Ávila-Gandía, Cristian Marín-Pagán, Antonio Luque, Pedro E. Alcaraz
      Purpose The aim of this study was to determine if heart rate variability (HRV) during incremental test could be used to estimate ventilatory threshold (VT) in professional basketball players, with sufficient precision to be used in their training. Furthermore, the second aim was to analyse the association between HRV and three methods of VT determination by gas analysis. Methods Twenty-four professional basketball players (age: 23.4 ± 4.9 years; height: 195.4 ± 9.8 cm; body mass: 92.2 ± 11.9 kg) performed an incremental running test to exhaustion. First ventilatory threshold (VT1) was determined by ventilatory equivalent (VE) and HRV and second ventilatory threshold (VT2) was determined by three methods of gases analysis (V-slope, VE and gas exchange ratio (R) and HRV). Pearson's coefficient (r) was used to detect differences between data and the strength of each relationship. The mean of absolute differences and Bland–Altman analysis were used to evaluate whether there was agreement. Results The results showed no significant differences in HR and oxygen consumption (VO2) at VT1 between the two methods. Furthermore, no significant differences among the methods of gases analysis and HRV were observed in speed, HR, and VO2 at VT2. Moreover, VTs estimated using HRV and gas methods were significantly correlated. Correlation was higher between R and HRV (r = 0.96) and VE and HRV (r = 0.96) than V-slope and HRV (r = 0.90). Conclusion These findings provide a practical, inexpensive approach for evaluating specific training loads when determining VT2 in basketball players. Therefore, HRV is an alternative method to determine VT2 without the application of expensive technology that limits its use to laboratories.


      PubDate: 2016-01-15T20:48:41Z
       
  • Correlates of long-term physical activity adherence in women

    • Abstract: Publication date: Available online 12 January 2016
      Source:Journal of Sport and Health Science
      Author(s): H. Sun, C.A. Vamos, S.B. Flory, R. DeBate, E.L. Thompson, J. Bleck
      Background Little is known about the factors that may influence women's adherence to moderate to vigorous physical activity (MVPA) using longitudinal data. The purpose of this study was to examine the correlates of long-term physical activity (PA) participation among women. Methods Female data from Waves I, III, and IV (n = 5,381) of the National Longitudinal Study of Adolescent to Adult Health (Add Health) were used for the analysis. The outcome of PA adherence was operationalized as (1) consistently physically active (at least 5 instances during the week) in both Waves III and IV (during adulthood), and (2) consistently not physically active or only physically active in either Wave III or IV. Predictor variables from Wave I (during adolescence) included race/ethnicity, PA level, self-perception of being physically fit, general health status, attempt to change weight, parents' income level, parents' education, well-being, depression, access to PA resources, days of physical education (PE), and grade level. Crude and adjusted logistic regression models were utilized to estimate the adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) for the outcome variable. Results PA levels during adolescence significantly predicted PA adherence (aOR = 1.67, 95% CI 1.35–2.05). Additionally, wanting to lose weight (aOR = 1.49, 95% CI 1.20–1.85), using fitness center in the neighborhood (aOR = 1.28, 95% CI 1.04–1.58), and having 5 days of PE a week (aOR = 1.50, 95% CI 1.09–2.06) were significant predictors. Women who did not perceive being physically fit (aOR = 0.65, 95% CI 0.45–0.95) and Black, non-Hispanics (aOR = 0.59, 95% CI 0.43–0.81) were less likely to adhere to PA. Conclusion The findings suggested that physically active adolescents were more likely to become active adults. Future research should address interventions (e.g., PE program, community resources) that may promote lifetime PA in women, with the goal of decreasing morbidity and mortality.


      PubDate: 2016-01-15T20:48:41Z
       
  • Postural control deficits identify lingering post-concussion neurological
           deficits

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Thomas A. Buckley, Jessie R. Oldham, Jaclyn B. Caccese
      Concussion, or mild traumatic brain injury, incidence rates have reached epidemic levels and impaired postural control is a cardinal symptom. The purpose of this review is to provide an overview of the linear and non-linear assessments of post-concussion postural control. The current acute evaluation for concussion utilizes the subjective balance error scoring system (BESS) to assess postural control. While the sensitivity of the overall test battery is high, the sensitivity of the BESS is unacceptably low and, with repeat administration, is unable to accurately identify recovery. Sophisticated measures of postural control, utilizing traditional linear assessments, have identified impairments in postural control well beyond BESS recovery. Both assessments of quiet stance and gait have identified lingering impairments for at least 1 month post-concussion. Recently, the application of non-linear metrics to concussion recovery have begun to receive limited attention with the most commonly utilized metric being approximate entropy (ApEn). ApEn, most commonly in the M/L plane, has successfully identified impaired postural control in the acute post-concussion timeframe even when linear assessments of instrumented measures are equivalent to healthy pre-injury values; unfortunately these studies have not gone beyond the acute phase of recovery. One study has identified lingering deficits in postural control, utilizing Shannon and Renyi entropy metrics, which persist at least through clinical recovery and return to participation. Finally, limited evidence from two studies suggest that individuals with a previous history of a single concussion, even months or years prior, may display altered ApEn metrics. Overall, non-linear metrics provide a fertile area for future study to further the understanding of postural control impairments acutely post-concussion and address the current challenge of sensitive identification of recovery.


      PubDate: 2016-01-15T20:48:41Z
       
  • Self-perceptions and social-emotional classroom engagement following
           structured physical activity among preschoolers: A feasibility study

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Spyridoula Vazou, Constantine Mantis, Gayle Luze, Jacqueline S. Krogh
      Background The well-rounded development of the child, including physical, cognitive, emotional, and social health, may be the most efficient route to well-being and academic success. The primary goal was to investigate the feasibility of implementing a 12-week structured program of physical activity (PA) incorporating cognitive, social, and emotional elements in preschool. Additionally, this study, using a within-subject design, examined the acute effects of a PA session on classroom engagement and changes on perceived competence and peer acceptance from the first to the last week of the program. Methods Twenty-seven preschoolers (M age = 4.2 years) completed the Pictorial Scale of Perceived Competence and Social Acceptance for Young Children before and after a twice-weekly PA program. Unobtrusive classroom observations were conducted for verbal, social, and affective engagement during the first and last week of the program, both following a structured PA session (experimental day) and on a day without PA (control day). Treatment fidelity was monitored to ensure that the intervention was delivered as designed. Results The children exhibited longer periods of verbal and social engagement during classroom periods that followed PA sessions than on non-PA days. Children also expressed more positive affect following PA sessions during the last week of the PA program. Despite high baseline scores, perceptions of general competence increased meaningfully (η 2 = 0.15, p = 0.05), driven by increases in perceptions of cognitive competence (η 2 = 0.15, p = 0.06). Conclusion This study demonstrates the feasibility of providing structured PA program to preschoolers. Moreover, these initial findings suggest that purposely designed, structured PA may help advance the social-emotional engagement and perceived competence of preschool children.


      PubDate: 2016-01-15T20:48:41Z
       
  • Parental social support, perceived competence and enjoyment in school
           physical activity

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Bo Shen, Erin Centeio, Alex Garn, Jeffrey Martin, Noel Kulik, Cheryl Somers, Nate McCaughtry
      Background Beginning in the elementary school years, there are differences among children on how they perceive their competence in physical activity (PA). Children's competence perceptions may influence their affective reactions to PA. A crucial question is how to motivate children who hold low competence perceptions to enhance their enjoyment and PA involvement. Because parents play critical roles in children's development and socialization, social support from parents can be an important factor to complement teachers' effort to enhance children's enjoyment and PA involvement. Purpose In this research we identified the associations among children's beliefs about parental social support, perceived competence and enjoyment in school PA. Methods Three hundred twenty children (9–11 years old) participated in a two-wave study. At the first wave, children completed questionnaires measuring their beliefs about parental social support, perceived competence and enjoyment in school PA; they reported their enjoyment again 8 months later at the second wave. Results Both concurrent and longitudinal analyses revealed that beliefs about parental social support were important factors associated with children's enjoyment in school PA, especially among girls with low competence perceptions. Conclusion Family socialization factors should be taken into consideration. The efficacy of individual and community-level strategies should be included and evaluated when designing effective intervention strategies that enhance children's PA in school.


      PubDate: 2016-01-15T20:48:41Z
       
  • Heat dissipating upper body compression garment: Thermoregulatory,
           cardiovascular, and perceptual responses

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Iker Leoz-Abaurrea, Nicholas Tam, Roberto Aguado-Jiménez
      Purpose The aim of the present study was to determine the effects of an upper body compression garment (UBCG) on thermoregulatory responses during cycling in a controlled laboratory thermoneutral environment (~23°C). A secondary aim was to determine the cardiovascular and perceptual responses when wearing the garment. Methods Sixteen untrained participants, (age 21.3 ± 5.7 years, VO2peak 50.88 ± 8.00 mL/min/kg, mean ± SD) performed two cycling trials in a thermoneutral environment (~23°C) wearing either UBCG or Control (Con) garment. Testing consisted of a 5-min rest on a cycle ergometer, followed by 4 bouts of cycling for 14 min at ~50% VO2peak, with 1-min rest between each bout. At the end of these bouts there was 10-min of passive recovery. During the entire protocol rectal temperature (Trec), skin temperature (Tskin), mean body temperature (Tbody) and heat storage (HS) were measured. Heart rate (HR), VO2, pH, hematocrit (Hct), plasma electrolytes, weight loss (Wloss), and perceptual responses were also measured. Results There were no significant differences between garments for Tskin, HS, HR, VO2, pH, Hct, plasma electrolyte concentration, Wloss, and perceptual responses during the trial. Trec did not differ between garment conditions during rest, exercise, or recovery although a greater reduction in Trec wearing UBCG (p = 0.01) was observed during recovery. Lower Tbody during recovery was found when wearing UBCG (36.82 ± 0.3°C vs. 36.99 ± 0.24°C). Conclusion Wearing a UBCG did not benefit thermoregulatory, cardiovascular, and perceptual responses during exercise although it was found to lower Tbody during recovery, which suggests that it could be used as a recovery tool after exercise.


      PubDate: 2016-01-15T20:48:41Z
       
  • The relationship between intermittent limit cycles and postural
           instability associated with Parkinson's disease

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): James R. Chagdes, Jessica E. Huber, Meredith Saletta, Meghan Darling-White, Arvind Raman, Shirley Rietdyk, Howard N. Zelaznik, Jeffrey M. Haddad
      Background Many disease-specific factors such as muscular weakness, increased muscle stiffness, varying postural strategies, and changes in postural reflexes have been shown to lead to postural instability and fall risk in people with Parkinson's disease (PD). Recently, analytical techniques, inspired by the dynamical systems perspective on movement control and coordination, have been used to examine the mechanisms underlying the dynamics of postural declines and the emergence of postural instabilities in people with PD. Methods A wavelet-based technique was used to identify limit cycle oscillations (LCOs) in the anterior–posterior (AP) postural sway of people with mild PD (n = 10) compared to age-matched controls (n = 10). Participants stood on a rigid foam surface while completing a dual task (speaking). Results There was no significant difference in the RMS of center of pressure between groups. Three out of 10 participants with PD demonstrated LCOs on the foam surface, while none in the control group demonstrated LCOs. An inverted pendulum model of bipedal stance was used to demonstrate that LCOs occur due to disease specific changes associated with PD: time-delay and neuromuscular feedback gain. Conclusion Overall, the LCO analysis and mathematical model appear to capture the subtle postural instabilities associated with mild PD. In addition, these findings provide insights into the mechanisms that lead to the emergence of unstable posture in patients with PD.


      PubDate: 2016-01-15T20:48:41Z
       
  • Effects of 12 weeks of barefoot running on foot strike patterns,
           inversion–eversion and foot rotation in long-distance runners

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Pedro A. Latorre-Román, Felipe García-Pinillos, Víctor M. Soto-Hermoso, Marcos Muñoz Jiménez
      Purpose The purpose of this study was to determine the effects of 12 weeks of barefoot running on foot strike patterns, inversion–eversion and foot rotation in long-distance runners. Methods Thirty-one endurance runners with no experience in barefoot running were randomized into a control group and an experimental group who received barefoot training. At pre-test and post-test, all subjects ran at low and high self-selected speeds on a treadmill. Data were collected by systematic observation of lateral and back recordings at 240 Hz. Results McNemar's test indicated significant changes (p < 0.05) in the experimental group at both high and low speed running in foot strike patterns, reducing the percentage of high rearfoot strikers and increasing the number of midfoot strikers. A significant increase (p < 0.05) of external rotation of the foot and a decrease of inversion occurred at comfortable speed in the experimental group. Conclusion Twelve weeks of barefoot running, applied progressively, causes significant changes in foot strike pattern with a tendency toward midfoot or forefoot strikes, regardless of running speed and significant changes in foot rotation at low speed, while the inversion was reduced in left foot at low speed with a tendency toward centered strike.


      PubDate: 2016-01-15T20:48:41Z
       
  • A history of low back pain affects pelvis and trunk coordination during a
           sustained manual materials handling task

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Joseph F. Seay, Shane G. Sauer, Tejash Patel, Tanja C. Roy
      Purpose The purpose of this study was to compare the coordination between the trunk and the pelvis during a sustained asymmetric repetitive lifting task between a group with a history of low back pain (HBP) and a group with no history of LBP (NBP). Methods Volunteers lifted a 11-kg box from ankle height in front to a shelf 45° off-center at waist height, and lowered it to the start position at 12 cycles/min for 10 min. Lifting side was alternated during the trial. Continuous relative phase was used to calculate coordination between the pelvis and trunk rotation at the beginning (Min 1), middle (Min 5), and end of the bout (Min 9). Results While there were no main effects for group, a significant interaction between time and group indicated that, in the frontal plane, the NBP group coordination was more anti-phase toward the end of the bout, with no such differences for the HBP group. Analysis of sagittal-axial (bend and twist) coordination revealed the HBP group coordination was more in-phase at the end of the bout over the entire cycle and for the lifting phase alone, with no such differences for the NBP group. Conclusion Differences between groups demonstrate residual consequences of LBP in an occupational scenario, even though the HBP group was pain-free for >6 months prior to data collection. More in-phase coordination in the HBP group may represent a coordination pattern analogous to “guarded gait” which has been observed in other studies, and may lend insight as to why these individuals are at increased risk for re-injury.


      PubDate: 2016-01-15T20:48:41Z
       
  • Athletes who train on unstable compared to stable surfaces exhibit unique
           postural control strategies in response to balance perturbations

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): D.S. Blaise Williams, Nicholas G. Murray, Douglas W. Powell
      Background Athletes have been shown to exhibit better balance compared to non-athletes. However, few studies have investigated how the surface on which athletes train affects the strategies adopted to maintain balance. Two distinct athlete groups who experience different types of sport-specific balance training are stable surface athletes (SSA) such as basketball players and those who train on unstable surfaces (USA) such as surfers. The purpose of this study was to investigate the effects of training surface on dynamic balance in athletes compared to non-athletes (NON). Methods Eight NON, eight SSA, and eight USA performed five 20-s trials in each of five experimental conditions including a static condition and four dynamic conditions in which the support surface translated in the anteroposterior (AP) or mediolateral (ML) planes using positive or negative feedback paradigms. Approximate entropy (ApEn) and root mean square distance (RMS) of the center of pressure were calculated for the AP and ML directions. Four 3 × 5 (group by condition) repeated measures ANOVAs were used to determine significant effects of group and condition on variables of interest. Results USA exhibited smaller ApEn values than SSA in the AP signals while no significant differences were observed in the ML center of pressure (CoP) signals. Generally, the negative feedback conditions were associated with significantly greater RMS values than the positive feedback conditions. Conclusion USA exhibit unique postural strategies compared to SSA. These unique strategies seemingly exhibit a direction-specific attribute and may be associated with divergent motor control strategies.


      PubDate: 2016-01-15T20:48:41Z
       
  • The effects of total ankle replacement on ankle joint mechanics during
           walking

    • Abstract: Publication date: Available online 11 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Henry Wang, Scott Brown
      Background End-stage ankle arthritis impairs joint function and patients' mobility. Total ankle replacement is a surgical procedure to treat severe ankle arthritis. Salto Talaris Anatomic AnkleTM (STAA) was designed to mimic the normal ankle anatomy and flexion/extension of the ankle movement. The purpose of this study was to examine the effect of an STAA ankle replacement on ankle joint function and mechanics during gait. Methods Five patients with end-stage unilateral ankle arthritis were recruited. Patients performed level walking in a laboratory setting on two occasions, prior to and 3 months after the STAA ankle surgeries. American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score was obtained. A 12-camera motion capture system was used to perform walking analysis. Gait temporo-spatial parameters and ankle joint mechanics were evaluated. Paired Student's t tests and non-parametric Wilcoxon matched tests were performed to examine the differences in biomechanical variables between the pre- and post-surgery walking conditions. Results Compared to the pre-surgical condition, at 3 months of post STAA surgery, patients experienced greater improvement in AOFAS hindfoot score (p = 0.0001); the STAA ankle demonstrated a 31% increase in ankle joint excursion (p = 0.045), a 22% increase in ankle plantarflexor moment (p = 0.075), a 60% increase in ankle power absorption (p = 0.023), and a 68% increase in ankle power production (p = 0.039). Patients also demonstrated a 23% increase in walking speed (p = 0.005), a 20% increase in stride length (p = 0.013), a 15% decrease in double support time (p = 0.043), and a 5% decrease in total stance time (p = 0.055). Conclusion Three months after surgeries, the STAA patients experienced improvements in ankle function and gait parameters. The STAA ankle demonstrated improved ankle mechanics during daily activities such as walking.


      PubDate: 2016-01-15T20:48:41Z
       
  • Non-linearity in the dynamic world of human movement

    • Abstract: Publication date: Available online 6 January 2016
      Source:Journal of Sport and Health Science
      Author(s): Li Li



      PubDate: 2016-01-10T18:46:48Z
       
 
 
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