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Akane Yoshimura, Robert Schleip and Norikazu Hirose

Context: Several studies have reported that self-massage using a foam roller (FR) increased joint range of motion (ROM) immediately. However, the mechanism of increasing ROM by the FR intervention has not been elucidated. Objective: To clarify the mechanism by investigating properties and morphological changes of muscles targeted by the FR intervention. Design: An interventional study. Setting: An athletic training laboratory. Participants: Ten male college volunteers with no injuries in their lower limbs (mean [SD]: age 23.8 [3.2] y, height 173.2 [4.9] cm, weight 69.5 [8.6] kg). Intervention: The FR intervention on the right plantar flexors for 3 minutes. Main Outcome Measures: Maximum ankle ROM, muscle hardness, and fascicle length of the gastrocnemius muscle at the neutral (0°), maximum dorsiflexion, and maximum plantar flexion positions. All measurements were conducted before (PRE) and after (POST) the FR intervention. Results: Dorsiflexion ROM increased significantly at POST (PRE: 13.6° [8.0°], POST: 16.6° [8.4°]; P < .001), although plantar flexion ROM did not change significantly between PRE and POST (PRE: 40.0° [6.1°], POST: 41.1° [4.9°]). There was no significant difference in muscle hardness and fascicle length between PRE and POST in any of the angles. Conclusions: Dorsiflexion ROM increased significantly by the FR intervention in the present study; however, muscle hardness and fascicle length did not change. FR may affect not only the muscle but also the fascia, tendon, and muscle-tendon unit. The FR protocol of the present study can be applied in clinical situations, because it was found to be effective to increase ROM.

Open access

Dean Barker, Gunn Nyberg and Hakan Larsson

Purpose: To describe student learning when physical education teacher and students attempted to develop movement capability. Methods: The study reports on the implementation of a 10-lesson pedagogical sequence. Data were generated using observations, interviews, and student diaries with one grade 9 class (26 students aged approximately 15 years) as they developed juggling capabilities. Data were analyzed using the notion of corporeal thresholds. Results: Results show that (a) a “throw–throw–catch–catch” pattern emerged as a corporeal threshold for juggling within the sequence; (b) most learners had crossed the threshold at the outset and were able to experiment with different forms of juggling during the sequence; (c) some students crossed the threshold during the sequence. These students experienced liminal phases, characterized by frustration and an initial feeling that they were juggling in the “wrong” way; and (d) some learners became stuck, pretended to know what to do, and did not cross the threshold during the 10 lessons. Discussion/Conclusion: Three issues related to the threshold approach are discussed: student identity and group membership, the process of learning, and the emotional dimensions of movement learning. This study is concluded with reflections on the implications of the results for scholarship.

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Emily A. Hall, Dario Gonzalez and Rebecca M. Lopez

Clinical Question: Does the medical model of organizational structure compared to either the academic or traditional models have a greater influence on job satisfaction and quality of life in collegiate athletic trainers? Clinical Bottom Line: Based on the quality of the person-oriented evidence available, the recommendation to adopt the medical model for athletic training staff would receive a Strength of Recommendation Taxonomy (SORT) grade of B.

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Alfred Nimmerichter, Bernhard Prinz, Matthias Gumpenberger, Sebastian Heider and Klaus Wirth

Purpose: To evaluate the predictive validity of critical power (CP) and the work above CP (W′) on cycling performance (mean power during a 20-min time trial; TT20). Methods: On 3 separate days, 10 male cyclists completed a TT20 and 3 CP and W′ prediction trials of 1, 4, and 10 min and 2, 7, and 12 min in field conditions. CP and W′ were modeled across combinations of these prediction trials with the hyperbolic, linear work/time, and linear power inverse-time (INV) models. The agreement and the uncertainty between the predicted and actual TT20 were assessed with 95% limits of agreement and a probabilistic approach, respectively. Results: Differences between the predicted and actual TT20 were “trivial” for most of the models if the 1-min trial was not included. Including the 1-min trial in the INV and linear work/time models “possibly” to “very likely” overestimated TT20. The INV model provided the smallest total error (ie, best individual fit; 6%) for all cyclists (305 [33] W; 19.6 [3.6] kJ). TT20 predicted from the best individual fit-derived CP, and W′ was strongly correlated with actual TT20 (317 [33] W; r = .975; P < .001). The bias and 95% limits of agreement were 4 (7) W (−11 to 19 W). Conclusions: Field-derived CP and W′ accurately predicted cycling performance in the field. The INV model was most accurate to predict TT20 (1.3% [2.4%]). Adding a 1-min-prediction trial resulted in large total errors, so it should not be included in the models.

Open access

Michal Botek, Jakub Krejčí, Andrew J. McKune and Barbora Sládečková

Purpose: Hydrogen-rich water (HRW) has been shown to have an antifatigue effect. This study assessed up-hill running performance, as well as physiological and perceptual responses after supplementation with 1680 mL HRW between 24 h and 40 min before running, in athletes of heterogeneous running ability. Methods: Sixteen males (mean [SD] age 31.6 [8.6] y, VO2max 57.2 [8.9] mL·kg−1·min−1, body fat 13.4% [4.4%]) participated in this study. Using a randomized, double-blind, placebo-controlled crossover design, participants consumed either HRW or placebo prior to performing two 4.2-km up-hill races separated by a week. Race time (RT), average race heart rate, and immediately postrace rating of perceived exertion were assessed. Results: After analysis of data for all runners, HRW effect was unclear (−10 to 7 s, 90% confidence interval) for RT, likely trivial for heart rate (−2 to 3 beats·min−1), and likely trivial for postrace rating of perceived exertion (−0.1 to 1.0). A possible negative correlation was found between RT differences and average RT (r = −.79 to −.15). HRW for the 4 slowest runners (RT = 1490 [91] s) likely improved the RT (−36 to −3 s), whereas for the 4 fastest runners (RT = 1069 [53] s) the performance effect of HRW was unclear (−10 to 26 s). Conclusions: HRW intake had an unclear antifatigue effect on performance in terms of mean group values. However, it appears that the magnitude of the antifatigue effect of HRW on performance depends on individual running ability.

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Shota Tanaka, Hiroki Ueta, Ryo Sagisaka, Shuji Sakanashi, Takahiro Hara and Hideharu Tanaka

Protective equipment in sports can be a barrier to sudden cardiac arrest (SCA) treatment, but no Kendo-related data are available. In order to enhance the SCA survival rate, we aimed to determine whether Kendo protective equipment should be removed before or after an automated external defibrillator (AED) has arrived by measuring the quality and timeframe of cardiopulmonary resuscitation administration. Eighteen collegiate female Kendo players were instructed to treat the patient with SCA under two conditions: (a) equipment removal [ER] condition; (b) no equipment removal [NER] condition. Chest compression initiation was delayed during simulated cardiac arrest situations in Kendo, but the SCA quality was much better without protective equipment. When a layperson is only a nonhealthcare professional female, Kendo protective equipment becomes a barrier for quick access during SCA treatment of Kendo players.

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Ray M. Merrill

Background: This study examined the effects of environmental, demographic, and lifestyle factors on leisure-time physical inactivity (LTPI). Methods: Analyses were based on county-level data in the contiguous United States. Statistical methods included simple regression, univariate, and multivariate 2-level organizational models (mixed models), and the intraclass correlation coefficient. Results: Higher average daily maximum air temperature was directly and indirectly (through smoking and obesity) positively associated with LTPI. Higher average fine particulate matter was positively associated with LTPI. Higher precipitation was negatively associated with LTPI. Altitude (≥1500 m) was associated with lower LTPI, directly because of better physical health at higher altitude and indirectly through temperature, fine particulate matter, precipitation, poverty, smoking, and obesity. Urban dwelling had direct and indirect (through poverty) negative associations with LTPI. Poverty had direct and indirect (through smoking and obesity) associations with LTPI. Smoking, poverty, and black race were each positively associated with LTPI. The association between black race and LTPI was explained by poverty. Modifying influences of gender, precipitation, and altitude were identified. Conclusions: The significant effects of temperature, fine particulate matter, precipitation, altitude, urban dwelling, poverty, smoking, and obesity on LTPI were both direct and indirect, and sex, precipitation, and altitude modified many of these associations.

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Brett D. Tarca, Thomas P. Wycherley, Paul Bennett, Anthony Meade and Katia E. Ferrar

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

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Christianne M. Eason, Stephanie M. Singe and Kelsey Rynkiewicz

Work–family guilt (WFG) is a measure used to assess guilt related to work interference with family and family interference with work. While work–family conflict (WFC) has been studied in the athletic trainer (AT) population, WFG has not. The purpose of this study was to gather descriptive data on WFG and to determine if WFC can predict WFG. There were significant positive associations between WFG and hours worked, but no sex differences in WFG or WFC exist. WFG was predicted by WFC. Results indicate higher levels of WFG and WFC are associated with a greater number of hours worked. Because guilt can negatively impact overall health, steps should be taken to mitigate WFC and WFG.