522 research outputs found
Overtraining: what do we know?
No full textThis chapter emphasises the (dis)balance between training and recovery, the definitions of the terms ‘functional overreaching’, ‘nonfunctional overreaching’, and the ‘overtraining syndrome’, as well as the diagnosis, prevalence, assessment, and prevention of the overtraining syndrome. This chapter is derived from the joint consensus statement of the European College of Sport Science and the American College of Sports Medicine regarding the prevention, diagnosis, and treatment of the Overtraining Syndrome (Meeusen et al., 2013)
Coordination of soccer players during preseason training
No full textThis study aimed to verify whether coordination improves as a result of a preseason soccer training. During 5 experimental sessions (days 1, 6, 11, 15, and 19), 16 semiprofessional male soccer players (22.0 ± 3.6 years) were administered 3 specific soccer tests (speed dribbling, shooting a dead ball, and shooting from a pass) and an interlimb coordination test (total duration of a trial: 60 seconds), consisting of isodirectional and nonisodirectional synchronized (1:1 ratio) hand and foot flexions and extensions at an increasing velocity of execution (80, 120, and 180 b·min(-1)). Furthermore, subjective ratings were monitored to assess the recovery state (RestQ) of the players, their perceived exertion (rating of perceived exertion [RPE]) for the whole body, and the perceived muscle pain (rating of muscle pain [RMP]) for the lower limbs and the internal training load by means of the session-RPE method. The ratios between post and pretraining RPE and RMP increased only during the first 2 experimental sessions and decreased after the second week of the training camp (p = 0.001). The Rest-Q showed increases (p < 0.05) for general stress, conflict/pressure, social recovery, and being in shape dimensions. Conversely, decreases (p < 0.05) were observed for social stress, fatigue, physical complaints dimensions. Throughout the preseason, the players improved their speed dribbling (p = 0.03), Shooting from a Pass (p = 0.02), and interlimb coordination (p < 0.0001) performances. These coordination tests succeeded in discriminating coordination in soccer players and could integrate field test batteries during the whole soccer season, because they were easily and inexpensively administrable by coaches
Subjective thermal strain impairs endurance performance in a temperate environment
No full textPurpose: The aim of this study was to test the hypothesis that subjective thermal strain can reduce endurance performance independently from the general physiological strain normally associated with impaired endurance performance in the heat. Methods: In 20 °C and 44% relative humidity, 12 endurance-trained athletes (1♀ 11♂; mean ± SD; age: 27 ± 6 y; VO 2max : 61 ± 6 ml/kg/min) performed a time to exhaustion (TTE) test in two different experimental conditions: with an electric heat pad applied to the subjects' upper back (HP) and control (CON: without heat pad). In both conditions, subjects cycled to volitional exhaustion at 70% of their VO 2max . Cardiorespiratory, metabolic, thermoregulatory and perceptual responses were measured throughout the TTE test and compared at 0%, 50% and 100% isotime and at exhaustion. Results: TTE was reduced by 9% in HP (2092 ± 305 s) compared to CON (2292 ± 344 s; p =.023). The main effect of condition on thermal discomfort at isotime (p =.002), the effect of condition on thermal sensation at 0% isotime (p =.004) and the condition by isotime interaction on rating of perceived exertion (p =.036) indicated higher subjective thermal strain in HP compared to CON. None of the measured cardiorespiratory, metabolic and thermoregulatory variables differed significantly between conditions. Conclusion: Our novel experimental manipulation (HP) was able to induce significant subjective thermal strain and reduce endurance performance in a temperate environment without inducing the general physiological strain normally associated with impaired endurance performance in the heat. These results suggest that subjective thermal strain is an important and independent mediator of the heat-induced impairment in endurance performance
Time-Discrete Vibrotactile Feedback Contributes to Improved Gait Symmetry in Patients With Lower-Limb Amputations: A Case Series
No full textReduced sensory feedback from lower-leg prostheses results in harmful gait patterns and entails a significant cognitive burden because users have to visually monitor their locomotion
Psychophysiological response to cognitive workload during symmetrical, asymmetrical and dual-task walking
No full textItem does not contain fulltextWalking with a lower limb prosthesis comes at a high cognitive workload for amputees, possibly affecting their mobility, safety and independency. A biocooperative prosthesis which is able to reduce the cognitive workload of walking could offer a solution. Therefore, we wanted to investigate whether different levels of cognitive workload can be assessed during symmetrical, asymmetrical and dual-task walking and to identify which parameters are the most sensitive. Twenty-four healthy subjects participated in this study. Cognitive workload was assessed through psychophysiological responses, physical and cognitive performance and subjective ratings. The results showed that breathing frequency and heart rate significantly increased, and heart rate variability significantly decreased with increasing cognitive workload during walking (p<.05). Performance measures (e.g., cadence) only changed under high cognitive workload. As a result, psychophysiological measures are the most sensitive to identify changes in cognitive workload during walking. These parameters reflect the cognitive effort necessary to maintain performance during complex walking and can easily be assessed regardless of the task. This makes them excellent candidates to feed to the control loop of a biocooperative prosthesis in order to detect the cognitive workload. This information can then be used to adapt the robotic assistance to the patient's cognitive abilities
The effect of teaching methodologies in promoting physical and cognitive development in children.
No full textThe practice of physical activity is believed to lead to improvement of motor skills and competences with several beneficial effects on present and future health, as well on psychological constrains of the child. However, no extensive data are available on the relationships between changes induced by motor activities on motor skills and executive functions. On the other hand, the data that have been accumulating in the recent years indicate that the (psychological) conditions that lead to improvement of executive functions can be easily applied to the context of organized motor activities. Teaching methodologies of physical activity rather than the activity itself appear to be relevant to enhance this important set of cognitive processes. From the educational perspective and considering the appreciation that movement-based games have among children, these conclusions highlight the potential significance of a revisited physical education in scholastic curricula for all ages
Benchmarking occupational exoskeletons: An evidence mapping systematic review
No full textPublisher Copyright: © 2021 The Author(s)Objectives: To provide an overview of protocols assessing the effect of occupational exoskeletons on users and to formulate recommendations towards a literature-based assessment framework to benchmark the effect of occupational exoskeletons on the user. Methods: PubMed (MEDLINE), Web of Science database and Scopus were searched (March 2, 2021). Studies were included if they investigated the effect of one or more occupational exoskeletons on the user. Results: In total, 139 eligible studies were identified, encompassing 33, 25 and 18 unique back, shoulder and other exoskeletons, respectively. Device validation was most frequently conducted using controlled tasks while collecting muscle activity and biomechanical data. As the exoskeleton concept matures, tasks became more applied and the experimental design more representative. With that change towards realistic testing environments came a trade-off with experimental control, and user experience data became more valuable. Discussion: This evidence mapping systematic review reveals that the assessment of occupational exoskeletons is a dynamic process, and provides literature-based assessment recommendations. The homogeneity and repeatability of future exoskeleton assessment experiments will increase following these recommendations. The current review recognises the value of variability in evaluation protocols in order to obtain an overall overview of the effect of exoskeletons on the users, but the presented framework strives to facilitate benchmarking the effect of occupational exoskeletons on the users across this variety of assessment protocols.The work presented in this paper was supported by the Research Foundation - Flanders (FWO) under grant no. S000118N SBO Exo4Work project.This article was enriched through work from COST Action 16116: Wearable Robots for Augmentation, Assistance or Substitution of Human Motor Functions, supported by COST (European Cooperation in Science and Technology). The work presented in this paper was supported by the Research Foundation - Flanders ( FWO ) under grant no. S000118N SBO Exo4Work project.Peer reviewe
Aging effects on prefrontal cortex oxygenation in a posture-cognition dual-task: an fNIRS pilot study
No full textThe aging process alters upright posture and locomotion control from an automatically processed to a more cortically controlled one. The present study investigated a postural-cognitive dual-task paradigm in young and older adults using functional Near- Infrared Spectroscopy (fNIRS).Methods: Twenty healthy participants (10 older adults 72 ± 3 y, 10 young adults 23 ± 3 y) performed a cognitive (serial subtractions) and a postural task (tandem stance) as single-tasks (ST) and concurrently as a dual-task (DT) while the oxygenation levels of the dorsolateral prefrontal cortex (DLPFC) were measured.Results: In the cognitive task, young adults performed better than older adults in both conditions (ST and DT) and could further increase the number of correct answers from ST to DT (all ps ≤ 0.027) while no change was found for older adults. No significant effects were found for the postural performance. Cerebral oxygenation values (O2Hb) increased significantly from baseline to the postural ST (p = 0.033), and from baseline to the DT (p = 0.031) whereas no changes were found in deoxygenated hemoglobin (HHb). Finally, the perceived exertion differed between all conditions (p ≤ 0.003) except for the postural ST and the DT (p = 0.204).Conclusions: There was a general lack of age-related changes except the better cognitive performance under motor-cognitive conditions in young compared to older adults. However, the current results point out that DLPFC is influenced more strongly by postural than cognitive load. Future studies should assess the different modalities of cognitive as well as postural load
Exploration of the validity and reliability of the "backache disability index" (BADIX) in patients with non-specific low back pain
No full text<b>BACKGROUND AND OBJECTIVES</b>\ud
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In clinical examinations of a patient with non-specific low back pain (LBP), there is a need to dispose over a valid and quick to perform rating system. The "Backache Disability Index" for LBP or BADIX includes rating of 5 trunk movements in erect position and a "Morning Back Stiffness" score, whereof the sum gives the BADIX (max. 20 points). The objective of this study was to explore the reliability, responsiveness and concurrent validity of the BADIX. Patients with LBP (n=100) were randomly assigned into a "control" group (n=40) in function of validity studies, and a "treatment" group (n=60) in function of responsiveness studies. The treatment group underwent two weekly sessions of in total 30 minutes of deep cross-friction on the thoraco-lumbar Erector spinae and gluteals. All patients completed the Oswestry Disability Questionnaire validated Dutch version (ODQ), the McGill Pain Questionnaire (MPQ). The impairment examination consists, besides current orthopaedic and neurologic examinations, of the new BADIX scoring system. \ud
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<b>RESULTS</b>\ud
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In our study the retest reliability after 3 days of the BADIX was perfect (n=039, r=0.95). A good correlation (p < 0.001) was found between BADIX at baseline, and Oswestry Disability Index (ODI) (n=93, r=0.76), and McGill-Quality of Life Index (r=0.74). Similar discriminative ability and effect size of measures was found for BADIX and ODI (n=54). It is proposed that the minimal detectable change should be equal or more than 2 points. \ud
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<b>CONCLUSIONS</b>\ud
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The "Backache Disability Index" appears to be a reliable and a valid assessment tool of morning stiffness and restricted spinal movements, and discriminates between successful and unsuccessful treatment outcome. The BADIX will allow patients to take snapshots of their daily treatment evolution, save them on their computer or tablets (apps) and share the results with their doctors and/or therapists. © 2013 - IOS Press and the authors. All rights reserved
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