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Kim Gammage, Desi McEwan, Lori Dithurbide, Alison Ede, Karl Erickson, Blair Evans, Larkin Lamarche, Sean Locke, Eric Martin and Kathleen Wilson

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Pai-Yun Cheng, Hsiao-Feng Chieh, Chien-Ju Lin, Hsiu-Yun Hsu, Jia-Jin J. Chen, Li-Chieh Kuo and Fong-Chin Su

This study aims toward an investigation and comparison of the digital force control and the brain activities of older adults and young groups during digital pressing tasks. A total of 15 young and 15 older adults were asked to perform force ramp tasks at different force levels with a custom pressing system. Near-infrared spectroscopy was used to collect the brain activities in the prefrontal cortex and primary motor area. The results showed that the force independence and hand function of the older adults were worse than that of the young adults. The cortical activations in the older adults were higher than those in the young group during the tasks. A significant hemodynamic between-group response and mild negative correlations between brain activation and force independence ability were found. Older adults showed poor force independence ability and manual dexterity and required additional brain activity to compensate for the degeneration.

Open access

Christopher P. Tomczyk, George Shaver and Tamerah N. Hunt

Clinical Scenario: Anxiety is a mental disorder that affects a large portion of the population and may be problematic when evaluating brain injuries such as concussion. The reliance of cognitive testing in concussion protocols call for the examination of potential cognitive alterations commonly seen in athletes with anxiety. Focused Clinical Question: Does anxiety affect neuropsychological assessments in healthy college athletes? Summary of Key Findings: Three studies were included: 1 cross-sectional study and 2 prospective cohort studies. One study examined the effect of a range of psychological issues on concussion baseline testing in college athletes. Another study examined the effect of anxiety on reaction time both before and after sport competition in college-aged athletes. The final study examined the effects of psychosocial issues on reaction time during demanding tasks in college athletes. The first study reported slower simple and complex reaction times in athletes with anxiety. The second study found that athletes with high trait anxiety have slower reaction times both before and after competition. The third study reported that demanding tasks led to increased state anxiety which slowed reaction time. Overall, all 3 studies support the adverse effect anxiety can have on cognitive testing in athletes. Clinical Bottom Line: College athletes who present with anxiety at baseline may be susceptible to decreased performance on neuropsychological assessments. Strength of Recommendation: There is level B evidence that anxiety in healthy college athletes can impact neuropsychological assessments, and level C evidence that anxiety at baseline concussion assessment impacts neuropsychological testing in college athletes.

Open access

Ryan D. Henke, Savana M. Kettner, Stephanie M. Jensen, Augustus C.K. Greife and Christopher J. Durall

ClinicalScenario: Low-intensity aerobic exercise (LIAEX) below the threshold of symptom exacerbation has been shown to be superior to rest for resolving prolonged (>4 wk) symptoms following sport-related concussion (SRC), but the effects of LIAEX earlier than 4 weeks after SRC need to be elucidated. Focused Clinical Question: Does LIAEX within the first 4 weeks following SRC hasten symptom resolution? Summary of Key Findings: Two randomized controlled trials (RCT) and 1 nonrandomized trial involving adolescent athletes (10–19 y) were included. One RCT reported faster recovery time with LIAEX versus placebo stretching. Likewise, recovery time was faster with LIAEX versus rest in the nonrandomized trial, but not in the underpowered RCT, although effect sizes were similar between these studies (0.5 and 0.4, respectively). All 3 studies reported a reduction in concussion symptom severity with LIAEX; however, the magnitude of symptom reduction across the recovery timeline was greater in the LIAEX group than the rest group in the nonrandomized trial, but not the 2 RCTs. Importantly, no adverse effects or incidence of delayed recovery from LIAEX were reported in any of the studies. Clinical Bottom Line: LIAEX initiated within 10 days after SRC may facilitate a faster recovery time versus placebo stretching or rest, although additional clinical trials are strongly advised to verify this. Strength of Recommendation: Level 1b and 2b evidence suggests subsymptom exacerbation LIAEX may decrease Postconcussion Symptom Scale scores and hasten symptom resolution in adolescent athletes following SRC.

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Kelly M. Meiners and Janice K. Loudon

Purpose/Background: Various methods are available for assessment of static and dynamic postural stability. The primary purpose of this study was to investigate the relationship between dynamic postural stability as measured by the Star Excursion Balance Test (SEBT) and static postural sway assessment as measured by the TechnoBody Pro-Kin in female soccer players. A secondary purpose was to determine side-to-side symmetry in this cohort. Methods: A total of 18 female soccer players completed testing on the SEBT and Technobody Pro-Kin balance device. Outcome measures were anterior, posterior medial, and posterior lateral reaches from the SEBT and center of pressure in the x- and y-axes as well as SD of movement in the forward/backward and medial/lateral directions from the force plate on left and right legs. Bivariate correlations were determined between the 8 measures. In addition, paired Wilcoxon signed-rank tests were performed to determine similarity between limb scores. Results: All measures on both the SEBT and postural sway assessment were significantly correlated when comparing dominant with nondominant lower-extremities with the exception of SD of movement in both x- and y-axes. When correlating results of the SEBT with postural sway assessment, a significant correlation was found between the SEBT right lower-extremity posterior lateral reach (r = .567, P < .05) and summed SEBT (r = .486, P < .05) and the center of pressure in the y-axis. A significant correlation was also found on the left lower-extremity, with SD of forward/backward movement and SEBT posterior medial reach (r = −.511, P < .05). Conclusions: Dynamic postural tests and static postural tests provide different information to the overall assessment of balance in female soccer players. Relationship between variables differed based on the subject’s lower-extremity dominance.

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Olfa Turki, Wissem Dhahbi, Sabri Gueid, Sami Hmaied, Marouen Souaifi and Riadh Khalifa

Purpose: To explore the effect of 4 different warm-up strategies using weighted vests and to determine the specific optimal recovery duration required to optimize the repeated change-of-direction (RCOD) performance in young soccer players. Methods: A total of 19 male soccer players (age 18 [0.88] y, body mass 69.85 [7.68] kg, body height 1.75 [0.07] m, body mass index 22.87 [2.23] kg·m−2, and body fat percentage 12.53% [2.59%]) completed the following loaded warm-up protocols in a randomized, counterbalanced cross-over, within-participants order and on separate days: weighted vest with a loading of 5% (WUV5%), 10% (WUV10%), 15% (WUV15%) body mass, and an unloaded condition (control). RCOD performance (total time, peak time, and fatigue index) was collected during the preintervention phase (5 min after the dynamic stretching sequence) for baseline values and immediately (at 15 min), at 4- and 8-minute postwarm-up intervention. Results: For each postwarm-up tested, recovery times (ie, 15 s, 4 min, and 8 min), of both total and peak times were faster following WUV5%, WUV10%, and WUV15%, compared with the unloaded condition (P ≤.001–.031, d = 1.28–2.31 [large]). There were no significant differences (P = .09–1.00, d = 0.03–0.72 [trivial–moderate]) in-between recovery times in both total and peak times following WUV5%, WUV10%, and WUV15%. However, baseline fatigue index score was significantly worse than all other scores (P ≤.001–.002, d = 1.35–2.46 [large]) following the loaded conditions. Conclusions: The findings demonstrated that a dynamic loaded warm-up increases an athlete’s initial RCOD performance up to the 8-minute postwarm-up intervention. Therefore, strength coaches need to consider using weighted vests during the warm-up for trained athletes in order to acutely optimize RCODs.

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Sommer Christie, Maurizio Bertollo and Penny Werthner

The purpose of this study was to investigate the effectiveness of a sensorimotor rhythm (SMR) neurofeedback training (NFT) and biofeedback training (BFT) intervention on ice hockey shooting performance. Specifically, the purpose was to examine (a) whether an NFT/BFT program could improve ice hockey shooting performance, (b) whether the implementation of an SMR-NFT intervention leads to neurological adaptations during performance, and (c) whether such neurological changes account for improvement in shooting performance. Using a longitudinal stratified random control design, results demonstrated that while both SMR-NFT/BFT and control groups improved performance, the rate of improvement for the SMR-NFT/BFT group was significantly higher than the control. Participants in the SMR-NFT/BFT group demonstrated the ability to significantly increase SMR power from pre- to postintervention in the lab. However, no significant changes in SMR power were found during shooting performance. This result may be suggestive of differing cortical activity present during motor-skill preparation.

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Pablo Jodra, Raúl Domínguez, Antonio J. Sánchez-Oliver, Pablo Veiga-Herreros and Stephen J. Bailey

Purpose: Dietary supplementation with inorganic nitrate (NO3 ) can enhance high-intensity exercise performance by improving skeletal muscle contractility and metabolism, but the extent to which this might be linked to altered psychophysiological processes is presently unclear. The purpose of this study was to assess the effects of NO3 -rich beetroot juice (BJ) supplementation on profile of mood states, ratings of perceived exertion (RPE), and performance in a 30-second Wingate cycle test. Methods: In a double-blind, randomized, cross-over study, 15 subjects completed 2 laboratory sessions after ingesting NO3 -rich or NO3 -depleted (placebo) BJ. Participants initially completed the profile of mood states questionnaire. Subsequently, participants completed a warm-up followed by a 30-second all-out Wingate cycling test. After the Wingate test, participants immediately indicated the RPE of their leg muscles (RPEmuscular), cardiovascular system (RPEcardio), and general RPE (RPEgeneral). Results: Compared with the placebo condition, supplementation with BJ increased peak power output (W peak) (+4.4%, 11.5 [0.7] vs 11.1 [1.0] W·kg−1; P = .039) and lowered the time taken to reach W peak (7.3 [0.9] vs 8.7 [1.5] s; P = .002) during the Wingate test. The profile of mood states score linked to tension was increased prior to the Wingate test (4.8 [3.0] vs 3.4 [2.4]; P = .040), and RPEmuscular was lowered immediately following the Wingate test (17.7 [1.6] vs 18.3 [1.0]; P = .031), after BJ compared with placebo ingestion. Conclusions: Acute BJ supplementation improved pre-exercise tension, 30-second Wingate test performance, and lowered postexercise RPEmuscular.

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Laura Žlibinaitė, Rima Solianik, Daiva Vizbaraitė, Dalia Mickevičienė and Albertas Skurvydas

Background: The benefits of weight loss programs on mood, cognitive, and motor behavior are largely limited to those of calorie restriction or exercise alone. Our aim was to investigate the effect of combined calorie restriction and aerobic exercise intervention on mood, brain activity, and cognitive and motor behavior in overweight and obese women. Methods: Participants aged 36–56 years were randomized to either a control or an experimental group (aerobic exercise + 12.5% energy intake reduction) for a 6-month period. Changes in brain-derived neurotrophic factor levels, mood, prefrontal cortex activity, cognitive and motor performance were assessed. Results: Confusion and depression increased in the control group (P < .05), whereas tension decreased in the experimental group (P < .05). Brain-derived neurotrophic factor level and learning of a speed–accuracy task remained unchanged. Although prefrontal cortex activity and executive functions were not affected, the reaction time of visual scanning and associative learning were improved in the experimental group (P < .05). An improvement in reaction time during the speed–accuracy task was observed (P < .05). Conclusion: Combined calorie restriction and aerobic exercise intervention improved the psychosocial state, had little impact on cognition, and no effect on brain activity and learning of the speed–accuracy task.

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Anthony Birat, David Sebillaud, Pierre Bourdier, Eric Doré, Pascale Duché, Anthony J. Blazevich, Dimitrios Patikas and Sébastien Ratel

Purpose: To examine the effect of drop height on vertical jumping performance in children with respect to sex and maturity status. Methods: Thirty-seven pre-pubertal, 71 circa-pubertal, and 69 post-pubertal boys and girls performed, in a randomized order, 2 squat jumps, 2 countermovement jumps, and 2 drop jumps (DJ) from heights of 20, 30, 40, 50, 60, and 70 cm. The trial with the best jump height in each test was used for analysis. Results: No significant sex × maturity status × jump type interaction for jump height was observed. However, on average, the children jumped higher in the countermovement jump than in squat jump and DJs (+1.2 and +1.6 cm, P < .001, respectively), with no significant differences between DJs and squat jumps or between DJs when increasing drop heights. Regarding DJs, 59.3% of the participants jumped higher from drop heights of 20 to 40 cm. Conclusions: Children, independent of sex and maturity status, performed best in the countermovement jump, and no performance gain was obtained by dropping from heights of 20 to 70 cm. During maturation, the use of drop heights between 20 and 40 cm may be considered in plyometric training, but the optimum height must be obtained individually.