107 research outputs found

    Recreational Water and Infection: A Review of Recent Findings

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    This paper reviews the latest evidence provided by epidemiological studies and quantitative microbial risk assessments (QMRAs) of infection risk from recreational water use. Studies for review were selected following a PubMed search for articles published between January 2010 and April 2014. Epidemiological studies show a generally elevated risk of gastrointestinal illness in bathers compared to non-bathers but often no clear association with water quality as measured by faecal indicator bacteria; this is especially true where study sites are impacted by non-point source pollution. Evidence from QMRAs support the lack of a consistent water quality association for non-point source-impacted beaches. It is suggested that source attribution, through quantified microbial source apportionment, linked with appropriate use of microbial source tracking methods should be employed as an integral part of future epidemiological surveys

    The test-retest reliability of different ankle joint center location techniques

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    Accurate and reliable joint identification is imperative for the collection of meaningful kinetic and kinematic data. Of the lower kinetic chain both the hip and knee joints have received a considerable amount of attention in 3D modelling. However, the reliability of methods to define the ankle joint center have received very little attention. This study investigated the reliability of the two marker method (TMM) and the functional ankle method (FAM) on estimating the ankle joint center. Furthermore, the effects of the two-marker method reliability for defining the ankle joint center when the ankle was covered with a brace or protector was investigated. 3D kinematic data was collected from ten participants (8 female and 2 male) whilst walking. The ankle joint center was defined twice using each test condition; TMM (WITHOUT), FAM (FUNCTIONAL), TMM when the ankle was covered with a brace (BRACE), and TMM when the ankle was covered with a protector (PROTECTOR). Intraclass correlations (ICC) were utilised to compare test and retest waveforms and paired samples t-tests were used to compare angular parameters. Significant differences were found in the test-retest angular parameters in the transverse and sagittal planes for the WITHOUT, BRACE, and FUNCTIONAL conditions. The strongest test-retest ICC’s were observed in the WITHOUT and PROTECTOR conditions. The findings of the current investigation indicate that there are fewer errors using the TMM when the ankle is uncovered or when covered with soft foam that is easy to palpate through

    Three-dimensional kinematic correlates of ball velocity during maximal instep soccer kicking in males

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    This is an Accepted Manuscript of an article published by Taylor & Francis Group in European Journal of Sport Science, on 23 April 2014, available online at: https://www.tandfonline.com/doi/abs/10.1080/17461391.2014.908956.Achieving a high ball velocity is important during soccer shooting, as it gives the goalkeeper less time to react, thus improving a player's chance of scoring. This study aimed to identify important technical aspects of kicking linked to the generation of ball velocity using regression analyses. Maximal instep kicks were obtained from 22 academy-level soccer players using a 10-camera motion capture system sampling at 500 Hz. Three-dimensional kinematics of the lower extremity segments were obtained. Regression analysis was used to identify the kinematic parameters associated with the development of ball velocity. A single biomechanical parameter; knee extension velocity of the kicking limb at ball contact Adjusted R(2) = 0.39, p ≤ 0.01 was obtained as a significant predictor of ball-velocity. This study suggests that sagittal plane knee extension velocity is the strongest contributor to ball velocity and potentially overall kicking performance. It is conceivable therefore that players may benefit from exposure to coaching and strength techniques geared towards the improvement of knee extension angular velocity as highlighted in this study.Peer reviewedFinal Accepted Versio

    QUANTIFYING AXIAL ROTATION OF UPPER EXTREMITY SEGMENTS

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    The calibrated anatomical systems technique (CAST) (Cappozzo et al, 1995) is an established method in gait and lower limb analyses. Its application to 6-degrees-of-freedom kinematic analyses and reduction of soft tissue artefact could make it particularly useful in quantifying axial rotation of the upper extremity. Such rotations have been established as being important in generating racket-head velocity in a variety of racket skills (Marshall and Elliott, 2000). The present study assesses the accuracy of CAST in quantifying the rotation of the forearm

    Repeated Acceleration Activity in Competitive Youth Soccer

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    Soccer match-play is increasingly characterised by short, high-speed bursts reliant on the ability to accelerate. Performance is impaired after peak acceleration activity and during the second half and may compromise a player’s effectiveness. To date, information about repeated acceleration sequences is lacking but would provide further insight into high-speed activity during competition. This study examined repeated acceleration ability (RAA) using GPS (5 Hz) and accelerometer (100 Hz), during 14 competitive youth soccer matches from the 2014–2015 season. Results showed that RAA profiles were relatively homogeneous, and there were no significant differences between playing positions. RAA activity was also relatively stable between playing halves and only the activity of forwards declined significantly. In summary, this study suggests that RAA is a generic requirement of match-play at this level but presents a specific focus for conditioning regimens

    The effects of Ankle Protectors on Lower Limb Kinematics in male football players: A comparison to Braced and Unbraced Ankles

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    Football (Soccer) players have a high risk of injuring the lower extremities. To reduce the risk of ankle inversion injuries ankle braces can be worn. To reduce the risk of ankle contusion injuries ankle protectors can be utilized. However, athletes can only wear one of these devices at a time. The effects of ankle braces on stance limb kinematics has been extensively researched, however ankle protectors have had little attention. Therefore, the current study aimed to investigate the effects of ankle protectors on lower extremity kinematics during the stance phase of jogging and compare them with braced and uncovered ankles. Twelve male participants ran at 3.4m.s-1 in three test conditions; ankle braces (BRACE), ankle protectors (PROTECTOR) and with uncovered ankles (WITHOUT). Stance phase kinematics were collected using an eight-camera motion capture system. Kinematic data between conditions were analysed using one-way repeated measures ANOVA. The results showed that BRACE (absolute range of motion (ROM) =10.72° & relative ROM =10.26°) significantly (P<0.05) restricted the ankle in the coronal plane when compared to PROTECTOR (absolute ROM =13.44° & relative ROM =12.82°) and WITHOUT (absolute ROM=13.64° & relative ROM =13.10°). It was also found that both BRACE (peak dorsiflexion =17.02° & absolute ROM =38.34°) and PROTECTOR (peak dorsiflexion=18.46° & absolute ROM =40.15°) significantly (P<0.05) reduced sagittal plane motion when compared to WITHOUT (peak dorsiflexion =19.20° & absolute ROM =42.66°). Ankle protectors' effects on lower limb kinematics closely resemble that of an unbraced ankle. Therefore, ankle protectors should only be used as a means to reduce risk of ankle contusion injuries and not implemented as a method to reduce the risk of ankle inversion injuries. Furthermore, the reductions found in sagittal plane motion of the ankle could possibly increase the bodies energy demand needed for locomotion when ankle protectors are utilised

    Water, Sanitation, and Hygiene Interventions to Reduce Diarrhoea in Less Developed Countries: A Systematic Review and Meta-analysis

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    The authors developed a comprehensive research strategy designed to identify all peer-reviewed articles, in any language, that presented water, sanitation, or hygiene interventions. Out of 2,120 publications, ultimately 40 studies were judged to contain relevant evidence. Most of the studies confined their study groups to children aged under 5 or 6 years. The identified studies were done in a wide range of settings, in many countries, and over many years. All of the interventions studied were found to reduce significantly the risks of diarrheal illness. The results generally agree with those from previous reviews, but water quality interventions (point-of-use water treatment) were found to be more effective than previously thought, and multiple interventions (consisting of combined water, sanitation, and hygiene measures) were not more effective than interventions with a single focus

    Repeated Acceleration Activity in Competitive Youth Soccer

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    Soccer match-play is increasingly characterised by short, high-speed bursts reliant on the ability to accelerate. Performance is impaired after peak acceleration activity and during the second half and may compromise a player&rsquo;s effectiveness. To date, information about repeated acceleration sequences is lacking but would provide further insight into high-speed activity during competition. This study examined repeated acceleration ability (RAA) using GPS (5 Hz) and accelerometer (100 Hz), during 14 competitive youth soccer matches from the 2014&ndash;2015 season. Results showed that RAA profiles were relatively homogeneous, and there were no significant differences between playing positions. RAA activity was also relatively stable between playing halves and only the activity of forwards declined significantly. In summary, this study suggests that RAA is a generic requirement of match-play at this level but presents a specific focus for conditioning regimens

    Rapid on-site identification of hazardous organic compounds at fire scenes using person-portable gas chromatography-mass spectrometry (GC-MS). Part 1: Air sampling and analysis

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    Recent advancements in person-portable instrumentation have resulted in the potential to provide contemporaneous results through rapid in-field analyses. These technologies can be utilised in emergency response scenarios to aid first responders in appropriate site risk assessment and management. Large metropolitan fires can pose great risk to human and environmental health due to the rapid release of hazardous compounds into the atmosphere. Understanding the release of these hazardous organics is critical in understanding their associated risks. Person-portable gas chromatography-mass spectrometry (GC-MS) was evaluated for its potential to provide rapid on-site analysis for real-time monitoring of hazardous organic compounds at fire scenes. Air sampling and analysis methods were developed for scenes of this nature. Controlled field testing demonstrated that the portable GC-MS was able to provide preliminary analytical results on the volatile organic compounds present in air samples collected from both active and extinguished fires. In-field results were confirmed using conventional laboratory-based air sampling and analysis procedures. The deployment of portable instrumentation could provide first responders with a rapid on-site assessment tool for the appropriate management of scenes, thereby ensuring environmental and human health is proactively protected and scientifically informed decisions are made for the provision of timely advice to stakeholders
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