262 research outputs found

    Comparison of psychometric properties between usual-week and past-week self-reported physical activity questionnaires: A systematic review

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    The aim was to critically appraise the methodological quality of studies and determine the psychometric qualities of Past-week and Usual-week Physical Activity Questionnaires (PAQs). Data sources were obtained from Pubmed and Embase. The eligibility criteria for selecting studies included: 1) at least one psychometric property of PAQs was examined in adults; 2) the PAQs either had a recall period of usual 7-days (Usual-week PAQs) within the past 12months or during the past 7-days (Past-week PAQs); and 3) PAQs were self-administered. Study quality was evaluated using the COSMIN taxonomy and the overall psychometric qualities evaluated using pre-established psychometric criteria. Overall, 45 studies were reviewed to assess the psychometric properties of 21 PAQs with the methodological quality of most studies showing good to excellent ratings. When the relationship between PAQs and other instruments (i.e., convergent validity) were compared between recall methods, Past-week PAQs appeared to have stronger correlations than Usual-week PAQs. For the overall psychometric quality, the Incidental and Planned Exercise Questionnaire for the Usual-week (IPEQ-WA) and for the Past-week (IPEQ-W) had the greatest number of positive ratings. For all included PAQs, very few psychometric properties were assessed with poor ratings for the majority of the overall qualities of psychometric properties indicating the limitation of current PAQs. More research that covers a greater spectrum of psychometric properties is required to gain a better understanding of the qualities of current PAQs

    Short-term results of a new self-locking cementless femoral stem: a prospective cohort study of the Lima MasterSL

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    Background: Total hip arthroplasty is a successful treatment for hip osteoarthritis. Primary and secondary implant fixation is dependent on implant design and plays an important role in the longevity of an implant. In this study, we assessed the self-locking cementless MasterSL femoral stem. Materials and methods: In this single-centre prospective study, 50 consecutive hips with the indication for total hip arthroplasty, who met the inclusion criteria, received the MasterSL stem from LIMA Corporate. Patients had pre- and post-operative clinical and radiological assessment and completed patient-reported outcome measures [Oxford Hip Score (OHS), Harris Hip Score (HHS) and Forgotten Joint Score (FJS)] at the 6-week and 6-, 12- and 24-month mark. Post-operative X-rays were assessed for osteointegration (Engh Score), alignment and subsidence. Results: After 2 years, aseptic survival was 100%. One hip had to be explanted due to early deep infection and was excluded from the study. At 2 years, the patients reported a significant improved HHS and OHS of 95.3 ± 5.8 and 46.1 ± 3.6 (mean ± standard deviation), respectively, compared to preoperatively. The mean ± standard deviation for the FJS was 86.4 ± 18.7 with two-thirds of the patients reporting a score above 85. The mean Engh score is 15.1 ± 5.9 (mean ± standard deviation) with no patient scoring below 1 which suggests good osteointegration in all femoral stems. Conclusions: The MasterSL femoral stem performed well in this short-term follow-up study, with high patient satisfaction and good signs of osteointegration. Long-term follow-up will be necessary to evaluate longevity

    Acute effects of traditional resistance training on sport-specific performance in adolescent cricket players

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    Cricket is a sport played internationally, which requires all players to partake in repetitive, high intensity bouts of exercise, to meet the anaerobic demands needed in a match. This can lead to cricket athletes undertaking resistance training to improve an aerobic performance. However, resistance training results in acute physiological stress known as exercise-induced muscle damage (EIMD), which has been reported to impair generic physical performance measures, subsequently impacting training practice and increasing injury susceptibility. The aim of this study was to examine the acute impact of EIMD on cricket bowling performance following traditional resistance training

    Structural, Magnetic and Electrical Properties of Co-Doped Barium Monoferrite BaFe2O4

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    Cobalt-substituted barium monoferrite with theformula BaCoxFe2-xO4 (x = 0.0 – 0.4, step 0.1) has been preparedthrough the sol-gel autocombustion method. Phase purity forprepared samples sintered at 700 and 1050 ̊C was analyzed byX-ray diffraction (XRD) patterns that indicated the formationof the typical orthorhombic phase for the samples. Fouriertransforminfrared (FTIR) spectroscopy was used to investigatethe effect of cobalt doping on the vibrational modes of thestudied samples. Scherrer and Williamson-Hall formulae wereused to define the microstrian and the crystallite size being inthe range of 44.1 to 59.7 nm, which was further confirmed withtransmission electron microscopy (TEM) images. Magneticcharacteristics including magnetic saturation and coercivitywere obtained from hysteresis loops traced using vibratingsample magnetometry (VSM). Magnetic properties werecorrelated with the composition of the prepared samples.Finally, dielectric measurements were operated to furtherconfirm the structural and magnetic analysis

    Postactivation potentiation effect of two lower body resistance exercises on repeated jump performance measures

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    This study examined the postactivation potentiation effects of combining squat and deadlift exercises on subsequent repeated jump performance. Fifteen, resistance-trained youth wrestlers were randomly allocated to either undertake back squats (BSq), deadlift (DL) or BSq and DL as supersets (BSq+DL), with a repeated jump protocol performed 8-minutes post-exercise in each session. Thereafter, a control condition (CON) was completed involving a general warm-up, followed by the repeated jump protocols. Power outputs, flight time, contact time and reactive strength index were recorded from each repeated jump protocol. Measures were compared between the BSq, DL and BSq+DL sessions and between sessions that generated the best power output (BEST) with CON via inferential statistics and effect size (ES) calculations. The BSq condition exhibited significantly greater power output compared to the CON condition (p<0.05, ES = 1.07), although no differences were identified for the other conditioning activities. Furthermore, power output, flight time and reactive strength index were significantly greater for the BEST compared to the CON condition (p<0.05, ES = 0.97-1.47). Results indicated that BSq was the optimal conditioning activity to increase power output during a repeated jump protocol. However, greater improvement during the BEST condition suggests that the type of conditioning activity should also be considered on an individual-basis

    Influence of blend ratio on the electrical characteristics of vulcanized SBR/NBR blends compatibilized by Cis-polybutadiene rubber

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    Blends composed of styrene butadiene rubber (SBR) and acrylonitrile-butadiene rubber (NBR) have been fabricated by melt-blending technique using two-roll mill blend machine. Cis-polybutadiene rubber (CBR) was used as a compatibilizer for enhancing the homogeneity between blend phases. No previous reports were found to discuss improving electrical properties of vulcanized SBR/NBR blends using unfilled rubber system (i.e. no fillers incorporation). SEM micrographs were utilized to verify the compatibility between two rubber ingredients in various blends, owing to the use of compatibilizer. Thermal stability of blends was investigated by differential thermal analysis (DTA) and differential scanning calorimetric (DSC) to evaluate the influence of blend ratio on the compatibility of investigated samples. Results revealed that the dielectric properties of blends are dramatically influenced by altering the blend ratio. The results revealed that the SEM observations confirmed the compatibilization effect of CBR on vulcanized SBR/NBR blends. Meanwhile, thermal properties of vulcanized SBR/NBR blends were enhanced with increasing of SBR contents in blends. The complex impedance graphs showed circular arcs showing the bulk contribution to overall electrical behavior for investigated vulcanized SBR/NBR blends. During I-V characteristics have been presented, where a remarkably change from linear behavior to nonlinear conduction at lower temperatures was found for 0SBR/100NBR blends. These findings supported and confirmed that the compatibilization effect and the blend ratio between rubber compositions have strongly influenced on their thermal and electrical properties of vulcanized blends
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