121 research outputs found

    Analysis of the X-Factor and X-Factor stretch during the completion of a golf practice session in low-handicap golfers

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    The X-Factor and X-Factor stretch have been positively correlated with golf long game performance. The aim of this study was to compare the X-Factor, X-Factor stretch and long game performance variables pre and following a golf practice session. A group of male golfers (n = 15, handicap = 3.3 ± 1.7) participated in the laboratory-based-study. Movement and performance variables were collected from five golf swings performed pre and following a golf practice session using a motion capture system and launch monitor respectively. Following the practice session, significant increases were observed in the X-Factor (p = 0.00, d = 0.22) and the X-Factor stretch (p = 0.02, d = 0.25). Specifically, the X-Factor increased from 52.82 ± 5.64 ° to 54.06 ± 5.61 ° following the practice session. The X-Factor stretch increased from 1.54 ± 1.05 ° to 1.90 ± 1.41 ° following the practice session. Significant differences were displayed in club head velocity (p = 0.00, d = 0.35), ball velocity (p = 0.01, d = 0.21) and actual carry distance (p = 0.00, d = 0.29) following the practice session. These findings suggest that performing multiple golf shots is not detrimental in terms of muscular fatigue in the long game performance. In actual fact, the findings demonstrate that performing 100 golf shots increases the X-Factor, X-Factor stretch patterns and performance variables which, in turn, increases long game performance. These findings can help PGA golf Professionals improve teaching practices and formulation of golf programmes and warm-up sessions

    Electromyographic analyses of the erector spinae muscles during golf swings using four different clubs

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    The purpose of this study was to compare the electromyography (EMG) patterns of the thoracic and lumbar regions of the erector spinae (ES) muscle during the golf swing whilst using four different golf clubs. Fifteen right-handed male golfers performed a total of twenty swings in random order using the driver, 4-iron, 7-iron and pitching-wedge. Surface EMG was recorded from the lead and trail sides of the thoracic and lumbar regions of the ES muscle (T8, L1 and L5 lateral to the spinous-process). Three-dimensional high-speed video analysis was used to identify the backswing, forward swing, acceleration, early and late follow-through phases of the golf swing. No significant differences in muscle-activation levels from the lead and trail sides of the thoracic and lumbar regions of the ES muscle were displayed between the driver, 4-iron, 7-iron and pitching-wedge (P > 0.05). The highest mean thoracic and lumbar ES muscle-activation levels were displayed in the forward swing (67–99% MVC) and acceleration (83–106% MVC) phases of the swing for all clubs tested. The findings from this study show that there were no significant statistical differences between the driver, 4-iron, 7-iron and pitching-wedge when examining muscle activity from the thoracic and lumbar regions of the ES muscle

    Commercial golf glove effects on golf performance and forearm muscle activity

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    The study aimed to determine whether or not commercial golf gloves influence performance variables and forearm muscle activity during golf play. Fifteen golfers participated in the laboratory based study, each performing 8 golf swings with a Driver and 7-iron whilst wearing a glove and 8 without wearing the glove. Club head speed, ball speed and absolute carry distance performance variables were calculated. Surface electromyography was recorded from the flexor digitorum superficialis and extensor carpi radialis brevis on both forearm muscles. Club head speed, ball speed and absolute carry distance was significantly higher when using the Driver with the glove in comparison to the Driver without the glove (p < 0.05). No significant differences were evident when using the 7-iron and no significant differences were displayed in muscle activity in either of the conditions. Findings from this study suggest that driving performance is improved when wearing a glove

    Intra-session and inter-day reliability of the Myon 320 electromyography system during sub-maximal contractions

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    Electromyography systems are widely used within the field of scientific and clinical practices. The reliability of these systems are paramount when conducting research. The reliability of Myon 320 Surface Electromyography System is yet to be determined. This study aims to determine the intra-session and inter-day reliability of the Myon 320 Surface Electromyography System. Muscle activity from fifteen participants was measured at the anterior deltoid muscle during a bilateral front raise exercise, the vastus lateralis muscle during a squat exercise and the extensor carpi radialis brevis (ECRB) muscle during an isometric handgrip task. Intra-session and inter-day reliability was calculated by intraclass correlation coefficient, standard error of measurement and coefficient of variation (CV). The normalized root mean squared (RMS) surface electromyographic signals produced good intra-session and inter-day testing intraclass correlation coefficient values (range: 0.63-0.97) together with low standard error of measurement (range: 1.49-2.32) and CV (range: 95% Confidence Interval = 0.36-12.71) measures for the dynamic-and-isometric contractions. The findings indicate that the Myon 320 Surface Electromyography System produces good to fair reliability when examining intra-session and inter-day reliability. Findings of the study provide evidence of the reliability of electromyography between trials which is essential during clinical testing.</p

    Comparison of thoracic and lumbar erector spinae muscle activation before and after a golf practice session

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    Lower back pain is commonly associated with golfers. The study aimed: to determine whether thoracic- and lumbar-erector-spinae muscle display signs of muscular fatigue after completing a golf practice session, and to examine the effect of the completed practice session on club head speed, ball speed and absolute carry distance performance variables. Fourteen right-handed male golfers participated in the laboratory-based-study. Surface electromyography (EMG) data was collected from the lead and trail sides of the thoracic- and lumbar-erector-spinae muscle. Normalized root mean squared (RMS) EMG activation levels and performance variables for the golf swings were compared before and after the session. Fatigue was assessed using median frequency (MDF) and RMS during the maximum voluntary contraction (MVC) performed before and after the session. No significant differences were observed in RMS thoracic- and lumbar-erector-spinae muscle activation levels during the five phases of the golf swing and performance variables before and after the session (p &gt; .05). Significant changes were displayed in MDF and RMS in the lead lower lumbar and all trail regions of the erector-spinae muscle when comparing the MVC performed before and after the session (p &lt; .05). Fatigue was evident in the trail side of the erector-spinae muscle after the session

    UK survey of occupational therapist’s and physiotherapist’s experiences and attitudes towards hip replacement precautions and equipment

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    Background: Total hip replacement (THR) is one of the most common orthopaedic procedures in the United Kingdom (UK). Historically, people following THR have been provided with hip precautions and equipment such as: raised toilet seats and furniture rises, in order to reduce the risks of dislocation post-operation. The purpose of this study was to determine current practices in the provision of these interventions in the UK for people following primary THR. Methods: A 27-question, self-administered online survey was developed and distributed to UK physiotherapists and occupational therapists involved in the management of people following primary THR (target respondents). The survey included questions regarding the current practices in the provision of equipment and hip precautions for THR patients, and physiotherapist’s and occupational therapist’s attitudes towards these practices. The survey was disseminated through print and web-based/social media channels. Results: 170 health professionals (87 physiotherapists and 83 occupational therapists), responded to the survey. Commonly prescribed equipment in respondent’s health trusts were raised toilet seats (95%), toilet frames and rails (88%), furniture raises (79%), helping hands/grabbers (77%), perching stools (75%) and long-handled shoe horns (75%). Hip precautions were routinely prescribed by 97% of respondents. Hip precautions were most frequently taught in a pre-operative group (52% of respondents). Similarly equipment was most frequently provided pre-operatively (61% respondents), and most commonly by occupational therapists (74% respondents). There was variability in the advice provided on the duration of hip precautions and equipment from up to six weeks post-operatively to life-time usage. Conclusions: Current practice on hip precautions and provision of equipment is not full representative of clinician’s perceptions of best care after THR. Future research is warranted to determine whether and to whom hip precautions and equipment should be prescribed post-THR as opposed to the current ‘blanket’ provision of equipment and movement restriction provided in UK practice

    Polymer Flow Through Porous Media: Numerical Prediction of the Contribution of Slip to the Apparent Viscosity.

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    The flow of polymer solutions in porous media is often described using Darcy’s law with an apparent viscosity capturing the observed thinning or thickening effects. While the macroscale form is well accepted, the fundamentals of the pore-scale mechanisms, their link with the apparent viscosity, and their relative influence are still a matter of debate. Besides the complex effects associated with the rheology of the bulk fluid, the flow is also deeply influenced by the mechanisms occurring close to the solid/liquid interface, where polymer molecules can arrange and interact in a complex manner. In this paper, we focus on a repulsive mechanism, where polymer molecules are pushed away from the interface, yielding a so-called depletion layer in the vicinity of the wall. This depletion layer acts as a lubricating film that may be represented by an effective slip boundary condition. Here, our goal is to provide a simple mean to evaluate the contribution of this slip effect to the apparent viscosity. To do so, we solve the pore-scale flow numerically in idealized porous media with a slip length evaluated analytically in a tube. Besides its simplicity, the advantage of our approach is also that it captures relatively well the apparent viscosity obtained from core-flood experiments, using only a limited number of inputs. Therefore, it may be useful in many applications to rapidly estimate the influence of the depletion layer effect over the macroscale flow and its relative contribution compared to other phenomena, such as non-Newtonian effects

    An electromyographic assessment pilot study on the reliability of the forearm muscles during multi-planar maximum voluntary contraction grip and wrist articulation in young males

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    BACKGROUND: Electromyographic systems are widely used in scientific and clinical practice. The reproducibility and reliability of these measures are crucial when conducting scientific research and collecting experimental data.OBJECTIVE: To test the reliability of surface electromyography signals from both the Flexor Digitorum Superficialis (FDS) and Extensor Carpi Radialis Brevis (ECRB) muscles of both the left and right arms during an individual, static multi-planar maximum voluntary contraction handgrip task using the Myon 320 system (Myon AG, Switzerland).METHODS: Eight right-handed male participants performed two maximal handgrip tests in five separate wrist positions using both hands. Muscle activity was recorded from both forearms. Reliability was measured using the Standard Error of Measurement (SEM), Coefficient of Variation (CV)and Intra-class correlation coefficients. Wrist joint position correlations within and between theFDS and ECRB muscle activities were also analysed.RESULTS: Absolute reliability was shown across all positions for both hands with CV and SEM recorded at below 10%. The output measures indicate that the Myon 320 system (Myon AG, Switzerland) produces good to fair reliability when assessing forearm muscle activity. Correlations in the left FDS muscles were negative. Correlations between the left ECRB and left FDS muscles were variable but positive between the right ECRB and right FDS muscles.CONCLUSIONS: The data sets retrieved from all participants were reliably evaluated. Wrist position correlations within and between the FDS and ECRB muscles may have been influenced by hand dominance. The findings demonstrate that the methods and systems outlined in this study can be used reliably in future research

    An evaluation of temporal and club angle parameters during golf swings using low cost video analyses packages

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    The purpose of this study was to compare swing time and golf club angle parameters during golf swings using three, two dimensional (2D) low cost, Augmented-Video-based-Portable-Systems (AVPS) (Kinovea, SiliconCoach Pro, SiliconCoach Live). Twelve right-handed golfers performed three golf swings whilst being recorded by a high-speed 2D video camera. Footage was then analysed using AVPS-software and the results compared using both descriptive and inferential statistics. There were no significant differences for swing time and the golf phase measurements between the 2D and 3D software comparisons. In general, the results showed a high Intra class Correlation Coefficient (ICC &gt; 0.929) and Cronbach’s Coefficient Alpha (CCA &gt; 0.924) reliability for both the kinematic and temporal parameters. The inter-rater reliability test for the swing time and kinematic golf phase measurements on average were strong. Irrespective of the AVPS software investigated, the cost effective AVPS can produce reliable output measures that benefit golf analyses
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