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Sample records for lx-17 hockey puck

  1. Ignition and Growth Modeling of LX-17 Hockey Puck Experiments

    SciTech Connect

    Tarver, C M

    2004-04-19

    Detonating solid plastic bonded explosives (PBX) formulated with the insensitive molecule triaminotrinitrobenzene (TATB) exhibit measurable reaction zone lengths, curved shock fronts, and regions of failing chemical reaction at abrupt changes in the charge geometry. A recent set of ''hockey puck'' experiments measured the breakout times of diverging detonation waves in ambient temperature LX-17 (92.5 % TATB plus 7.5% Kel-F binder) and the breakout times at the lower surfaces of 15 mm thick LX-17 discs placed below the detonator-booster plane. The LX-17 detonation waves in these discs grow outward from the initial wave leaving regions of unreacted or partially reacted TATB in the corners of these charges. This new experimental data is accurately simulated for the first time using the Ignition and Growth reactive flow model for LX-17, which is normalized to a great deal of detonation reaction zone, failure diameter and diverging detonation data. A pressure cubed dependence for the main growth of reaction rate yields excellent agreement with experiment, while a pressure squared rate diverges too quickly and a pressure quadrupled rate diverges too slowly in the LX-17 below the booster equatorial plane.

  2. Performance Prediction for a Hockey-Puck Silicon Crystal Monochromator at the Advanced Photon Source

    NASA Astrophysics Data System (ADS)

    Liu, Zunping; Rosenbaum, Gerd; Navrotski, Gary

    2014-03-01

    One of the Key Performance Parameters of the upgrade of the Advanced Photon Source (APS) is the increase of the storage ring current from 100 to 150 mA. In order to anticipate the impact of this increased heat load on the X-ray optics of the beamlines, the APS has implemented a systematic review, by means of finite element analysis and computational fluid dynamics, of the thermal performance of the different types of monochromators installed at the highest-heat-load insertion device beamlines. We present here simulations of the performance of a directly liquid nitrogen-cooled silicon crystal, the hockey-puck design. Calculations of the temperature and slope error at multiple ring currents under multiple operational conditions, including the influence of power, cooling, and diffraction surface thickness are included.

  3. CHARACTERIZATION OF THERMALLY DAMAGED LX-17

    SciTech Connect

    Hsu, P C

    2007-07-11

    Thermal damage was applied to LX-17 at 190 C for several hours. The damaged LX-17 samples, after cooled down to room temperature, were characterized for their material properties (density, porosity, permeability, moduli), safety, and performance. Weight losses upon thermal exposure were insignificant (< 0.1% wt.). The damaged LX-17 samples expanded, resulting in a bulk density reduction of 4.3%. Subsequent detonation measurements (cylinder tests) were conducted on the thermally-damaged LX-17 samples. The results showed that the fractions of damaged LX-17 reacted were slightly lower than those of pristine LX-17. The thermally damaged LX-17 had a detonation velocity of 7.315 mm/{micro}s, lower than that (7.638 mm/{micro}s) of pristine LX-17. Detonation energy density for the damaged LX-17 was 5.08 kJ/cm{sup 3}, about 9.0% lower than the detonation energy density of 5.50 kJ/cm{sup 3} for the pristine LX-17. The break-out curves showed reaction zone lengths for pristine LX-17 and damaged LX-17 were similar but the damaged samples had ragged detonation fronts.

  4. Multiple shock initiation of LX-17

    SciTech Connect

    Tarver, C.M.; Cook, T.M.; Urtiew, P.A.; Tao, W.C.

    1993-07-01

    The response of the insensitive TATB-based high explosive LX-17 to multiple shock impacts is studied experimentally in a four inch gas gun using embedded manganin gauges and numerically using the ignition and growth reactive flow model of shock initiation and detonation. Pressure histories are reported for LX-17 cylinders which are subjected to sustained shock pulses followed by secondary compressions from shocks reflected from metal discs attached to the backs of the explosive targets. These measured and calculated pressure histories show that the threshold for hot spot growth in LX-17 is 7 GPa, that LX-17 can be dead pressed at slightly lower pressures, and that the reaction rates behind reflected shocks increase greatly as the impedance of the metal increases. A study of the response of LX-17 to the collision of two reacting, diverging shocks forming a Mach stem wave inside the LX-17 charge demonstrated that this interaction can result in a high pressure region of sufficient size and strength to cause detonation under certain conditions.

  5. Puck collisions

    NASA Astrophysics Data System (ADS)

    Hauge, E. H.

    2012-09-01

    Collisions between two ice hockey pucks sliding on frictionless ice are studied, with both inelasticity and frictional contact between the colliding surfaces of the two pucks taken into account. The latter couples translational and rotational motion. The full solution depends on the sign and magnitude of the initial mismatch between the surface velocities at the point of contact. The initial state defines two physically distinct regimes for the friction coefficient. To illustrate the complexities, we discuss at length the typical situation (well known from curling) when puck number 1 is initially at rest, and is hit by puck number 2 with an arbitrary impact parameter, velocity and angular velocity. We find that the total outgoing angle between the pucks exceeds \\frac{1}{2}\\pi if and only if the collision leads to a net increase in the translational part of the kinetic energy. The conditions for this to happen are scrutinized, and the results are presented both analytically and numerically by a set of representative curves. This paper is written with an ambitious undergraduate, and her teacher, in mind.

  6. Air Gap Effects in LX-17

    SciTech Connect

    Souers, P C; Ault, S; Avara, R; Bahl, K L; Boat, R; Cunningham, B; Gidding, D; Janzen, J; Kuklo, D; Lee, R; Lauderbach, L; Weingart, W C; Wu, B; Winer, K

    2005-09-26

    Three experiments done over twenty years on gaps in LX-17 are reported. For the detonation front moving parallel to the gaps, jets of gas products were seen coming from the gaps at velocities greater than the detonation velocity. A case can be made that the jet velocity increased with gap thickness but the data is scattered. For the detonation front moving transverse to the gap, time delays were seen. The delays roughly increase with gap width, going from 0-70 ns at 'zero gap' to around 300 ns at 0.5-1 mm gap. Larger gaps of up to 6 mm width almost certainly stopped the detonation, but this was not proved. Real-time resolution of the parallel jets and determination of the actual re-detonation or failure in the transverse case needs to be done in future experiments.

  7. Evaluation of LX-17 made from water-aminated TATB

    SciTech Connect

    Osborn, A.G.

    1982-10-01

    Water-aminated TATB was formulated into LX-17 at both Pantex and Holston. Mechanical properties, growth, pressed density, corner turning and gap sensitivity properties were compared. Mechanical properties, corner turning and gap sensitivity were similar to those of LX-17 made from dry-aminated TATB. Permanent expansion resulting from thermal aging may be slightly greater than that of LX-17 with dry-aminated TATB.

  8. LX-17-1 Stockpile Returned Material Lot Comparison

    SciTech Connect

    Gagliardi, F.; Pease, S.; Willey, T.

    2015-02-18

    Many different lots of LX-17 have been produced over the years. Two varieties of LX-17, LX-17-0 and LX-17-1, have at one point or another been a part of the Livermore stockpile systems. LX-17-0 was made with dry-aminated TATB whereas LX-17-1 was made with wet-aminated TATB. Both versions have the same TATB to Kel-F 800 mass ratio of 92.5%/7.5%. Both kinds of LX-17 were formulated at Holston during the late 1970s or early to mid-1980s and were certified to have met the necessary specifications that cover the purity, particle size range, explosive to binder ratio, etc. In recent years, Trevor Willy and others have performed a detailed evaluation of solid parts made from each of the LX-17 lots manufactured at Holston. Using the Advanced Light Source at LBNL, Willey and his colleagues radiographed many samples from isostatic pressings using the same scanning conditions. In their investigation they identified that even though the bulk composition can be the same, there may exist a large spread in how smoothly the TATB and binder were distributed within the radiographed volume of different lots of material.1 Overall, the dry-aminated TATB-based material, LX-17-0, had a smooth TATB and binder distribution, whereas the wet-aminated TATB-based LX-17-1 showed a wide range of binder distributions. The results for five different LX-17-1 lots are shown in Figure 1. The wide variation in material distribution has raised the question about whether or not this sort variability will cause significant differences in mechanical behavior.

  9. LX-17 and ufTATB Data for Corner-Turning, Failure and Detonation

    SciTech Connect

    Souers, P C; Lauderbach, L; Garza, R; Vitello, P; Hare, D E

    2010-02-03

    Data is presented for the size (diameter) effect for ambient and cold confined LX-17, unconfined ambient LX-17, and confined ambient ultrafine TATB. Ambient, cold and hot double cylinder corner-turning data for LX-17, PBX 9502 and ufTATB is presented. Transverse air gap crossing in ambient LX-17 is studied with time delays given for detonations that cross.

  10. LX-17 Deflagration at High Pressures and Temperatures

    SciTech Connect

    Koerner, J; Maienschein, J; Black, K; DeHaven, M; Wardell, J

    2006-10-23

    We measure the laminar deflagration rate of LX-17 (92.5 wt% TATB, 7.5 wt% Kel-F 800) at high pressure and temperature in a strand burner, thereby obtaining reaction rate data for prediction of thermal explosion violence. Simultaneous measurements of flame front time-of-arrival and temporal pressure history allow for the direct calculation of deflagration rate as a function of pressure. Additionally, deflagrating surface areas are calculated in order to provide quantitative insight into the dynamic surface structure during deflagration and its relationship to explosion violence. Deflagration rate data show that LX-17 burns in a smooth fashion at ambient temperature and is represented by the burn rate equation B = 0.2P{sup 0.9}. At 225 C, deflagration is more rapid and erratic. Dynamic deflagrating surface area calculations show that ambient temperature LX-17 deflagrating surface areas remain near unity over the pressure range studied.

  11. Temperature-dependent shock initiation of LX-17 explosive

    SciTech Connect

    Lee, R.S.; Chau, H.H.; Druce, R.L.; Moua, K.

    1995-02-01

    LX-17 samples, heated to temperatures up to 250 C, were impacted by 3 to 10-mm-wide, 50.8-mm-long strips of 0.13-mm-thick Kapton polyimide film at velocities up to 7.7 km/s. The Kapton strips were laminated onto a thin aluminum bridge foil and were launched to the desired velocity by discharging a capacitor bank through the foil, causing the foil to explode. The LX-17 samples were confined in a steel holder and heated in an oven to the desired temperature. After the capacitor bank was charged, the LX-17 sample in its steel holder was remotely drawn out of the oven on rails and positioned over the bridge-foil/Kapton-strip laminate. When the sample was in position, the bank was discharged, launching the Kapton strip against the LX-17 surface. The shock initiation threshold was measured for 3, 7, and 10-mm-wide strips at room temperature, 200 C and 250 C. The authors found a significant reduction in the velocity threshold and in the critical area for initiation when the samples were heated. The authors compare the results with the earlier data of Bloom, who measured the initiation threshold of LX-17 over the density range 1.8--1.91 g/cm{sup 3} at room temperature and {minus}54 C. LX-17 has a large coefficient of thermal expansion, as reported by Urtiew, et al., which reduces its density significantly t elevated temperatures. They find that the change of shock initiation threshold with temperature is consistent with the change in sample density, using the relation between threshold and density reported by Bloom.

  12. Detonation Shock Dynamics (DSD) Calibration for LX-17

    SciTech Connect

    Aslam, Tariq D

    2012-04-24

    The goal of this report is to summarize the results of a Detonation shock dynamics (DSD) calibration for the explosive LX-17. Considering that LX-17 is very similar to PBX 9502 (LX-17 is 92.5% TATB with 7.5% Kel-F 800 binder, while PBX 9502 is 95% TATB with 5% Kel-F 800 binder), we proceed with the analysis assuming many of the DSD constants are the same. We only change the parameters D{sub CJ}, B and {bar C}{sub 6} ({bar C}{sub 6} controls the how D{sub CJ} changes with pressing density). The parameters D{sub CJ} and {bar C}{sub 6} were given by Josh Coe and Sam Shaw's EOS. So, only B was optimized in fitting all the calibration data. This report first discusses some general DSD background, followed by a presentation of the available dataset to perform the calibration, and finally gives the results of the calibration and draws some conclusions. A DSD calibration of LX-17 has been conducted using the existing diameter effect data and shock shape records. The new DSD fit is based off the current PBX 9502 calibration and takes into account the effect of pressing density. Utilizing the PBX 9502 calibration, the effects of initial temperature can also be taken into account.

  13. Dead Zones in LX-17 and PBX 9502

    SciTech Connect

    Souers, P C; Andreski, H G; Batteux, J; Bratton, B; Cabacungan, C; Cook, III, C F; Fletcher, S; Garza, R; Grimsley, D; Handly, J; Hernandez, A; McMaster, P; Molitoris, J D; Palmer, R; Prindiville, J; Rodriguez, J; Schneberk, D; Wong, B; Vitello, P

    2005-09-06

    Pin and X-ray corner-turning data have been taken on ambient LX-17 and PBX 9052, and the results are listed in tables as an aid to future modeling. The results have been modeled at 4 zones/mm with a reactive flow approach that varies the burn rate as a function of pressure. A single rate format is used to simulate failure and detonation in different pressure regimes. A pressure cut-off must also be reached to initiate the burn. Corner-turning and failure are modeled using an intermediate pressure rate region, and detonation occurs at high pressure. The TATB booster is also modeled using reactive flow, and X-ray tomography is used to partition the ram-pressed hemisphere into five different density regions. The model reasonably fits the bare corner-turning experiment but predicts a smaller dead zone with steel confinement, in contradiction with experiment. The same model also calculates the confined and unconfined cylinder detonation velocities and predicts the failure of the unconfined cylinder at 3.75 mm radius. The PBX 9502 shows a smaller dead zone than LX-17. An old experiment that showed a large apparent dead zone in Comp B was repeated with X-ray transmission and no dead zone was seen. This confirms the idea that a variable burn rate is the key to modeling. The model also produces initiation delays, which are shorter than those found in time-to-detonation.

  14. LX-17 Corner-Turning and Reactive Flow Failure

    SciTech Connect

    Souers, P C; Andreski, H; Cook III, C F; Garza, R; Pastrone, R; Phillips, D; Roeske, F; Vitello, P; Molitoris, J

    2004-03-11

    We have performed a series of highly-instrumented experiments examining corner-turning of detonation. A TATB booster is inset 15 mm into LX-17 (92.5% TATB, 7.5% kel-F) so that the detonation must turn a right angle around an air well. An optical pin located at the edge of the TATB gives the start time of the corner-turn. The breakout time on the side and back edges is measured with streak cameras. Three high-resolution X-ray images were taken on each experiment to examine the details of the detonation. We have concluded that the detonation cannot turn the corner and subsequently fails, but the shock wave continues to propagate in the unreacted explosive, leaving behind a dead zone. The detonation front farther out from the corner slowly turns and eventually reaches the air well edge 180{sup o} from its original direction. The dead zone is stable and persists 7.7 {micro}s after the corner-turn, although it has drifted into the original air well area. Our regular reactive flow computer models sometimes show temporary failure but they recover quickly and are unable to model the dead zones. We present a failure model that cuts off the reaction rate below certain detonation velocities and reproduces the qualitative features of the corner-turning failure.

  15. Mesoscale Modeling of LX-17 Under Isentropic Compression

    SciTech Connect

    Springer, H K; Willey, T M; Friedman, G; Fried, L E; Vandersall, K S; Baer, M R

    2010-03-06

    Mesoscale simulations of LX-17 incorporating different equilibrium mixture models were used to investigate the unreacted equation-of-state (UEOS) of TATB. Candidate TATB UEOS were calculated using the equilibrium mixture models and benchmarked with mesoscale simulations of isentropic compression experiments (ICE). X-ray computed tomography (XRCT) data provided the basis for initializing the simulations with realistic microstructural details. Three equilibrium mixture models were used in this study. The single constituent with conservation equations (SCCE) model was based on a mass-fraction weighted specific volume and the conservation of mass, momentum, and energy. The single constituent equation-of-state (SCEOS) model was based on a mass-fraction weighted specific volume and the equation-of-state of the constituents. The kinetic energy averaging (KEA) model was based on a mass-fraction weighted particle velocity mixture rule and the conservation equations. The SCEOS model yielded the stiffest TATB EOS (0.121{micro} + 0.4958{micro}{sup 2} + 2.0473{micro}{sup 3}) and, when incorporated in mesoscale simulations of the ICE, demonstrated the best agreement with VISAR velocity data for both specimen thicknesses. The SCCE model yielded a relatively more compliant EOS (0.1999{micro}-0.6967{micro}{sup 2} + 4.9546{micro}{sup 3}) and the KEA model yielded the most compliant EOS (0.1999{micro}-0.6967{micro}{sup 2}+4.9546{micro}{sup 3}) of all the equilibrium mixture models. Mesoscale simulations with the lower density TATB adiabatic EOS data demonstrated the least agreement with VISAR velocity data.

  16. Plutonium Immobilization Puck Handling

    SciTech Connect

    Kriikku, E.

    1999-01-26

    The Plutonium Immobilization Project (PIP) will immobilize excess plutonium and store the plutonium in a high level waste radiation field. To accomplish these goals, the PIP will process various forms of plutonium into plutonium oxide, mix the oxide powder with ceramic precursors, press the mixture into pucks, sinter the pucks into a ceramic puck, load the pucks into metal cans, seal the cans, load the cans into magazines, and load the magazines into a Defense Waste Processing Facility (DPWF) canister. These canisters will be sent to the DWPF, an existing Savannah River Site (SRS) facility, where molten high level waste glass will be poured into the canisters encapsulating the ceramic pucks. Due to the plutonium radiation, remote equipment will perform these operations in a contained environment. The Plutonium Immobilization Project is in the early design stages and the facility will begin operation in 2005. This paper will discuss the Plutonium Immobilization puck handling conceptual design and the puck handling equipment testing.

  17. Corner turning and shock desensitization experiments plus numerical modeling of detonation waves in the triaminotrinitrobenzene based explosive LX-17.

    PubMed

    Tarver, Craig M

    2010-03-01

    Five new experiments are reported that tested both detonation wave corner turning and shock desensitization properties of the triaminotrinitrobenzene (TATB) based plastic bonded explosive (PBX) LX-17. These experiments used small pentaerythritol tetranitrate (PETN) charges to initiate hemispherical ultrafine TATB (UF TATB) boosters, which then initiated LX-17 hemispherical detonations. The UF TATB boosters were placed under steel shadow plates embedded in the LX-17 cylindrical charges, which were covered by thin aluminum plates. The LX-17 detonation waves propagated outward until they reached the aluminum plates, which were instrumented with photonic Doppler velocimetry probes to measure their axial free surface velocities. X-ray radiographs and framing camera images were taken at various times. The LX-17 detonations propagated around the two corners of the steel shadow plates and into thin LX-17 layers placed between the steel and the top aluminum plates. The detonation waves were met there by weak diverging shocks that propagated through the steel plates and imparted 1-2 GPa pressures to these unreacted LX-17 layers. These weak shock waves compressed and desensitized the unreacted LX-17, resulting in failures of the LX-17 detonation waves. The hydrodynamics of double corner turning and shock desensitization in the five experiments were modeled in two dimensions using the Ignition and Growth LX-17 detonation reactive flow model. The calculated arrival times and axial free surface velocity histories of the top aluminum plates were in excellent agreement with the experimental measurements. PMID:20141191

  18. CTE and Ratchet Growth Measurements on LX17-1 and Constituents

    SciTech Connect

    Cunningham, B; Weese, R; Lewis, P; Harwood, P; Tran, T

    2002-02-22

    Dimensional changes in PBX materials resulting from temperature change are of interest to engineers, designers and modelers. In this paper we present data from recent measurements made on LX17-1, as well as on the material's binder and its energetic constituent. LX17-1 is made from 7.5% KEL-F 800 binder combined with 92.5% wet aminated TATB energetic crystals. Due apparently to the anisotropic expansionary behavior of the TATB, the material exhibits irreversible growth, in addition to the usual reversible expansions and contractions associated with temperature change. In an effort understand reversible and irreversible growth behavior and to verify consistency between our measurements and those made historically, measurements were performed on billet pressed LX17-1, on die pressed TATB, and on KEL-F alone. It is important to realize that, for materials involving TATB, expansionary behavior results from the combined effects of reversible and irreversible (ratchet growth) phenomena.

  19. First-Generation Jet Propulsion Laboratory "Hockey-Puck" Free-Flying Magnetometers for Distributed In-Situ Multiprobe Measurement of Current Density Filamentation in the Northern Auroral Zone: Enstrophy Mission

    NASA Technical Reports Server (NTRS)

    Javadi, H.; Blaes, B.; Boehm, M.; Boykins, K.; Gibbs, J.; Goodman, W.; Lieneweg, U.; Lux, J.; Lynch, K.; Narvaez, P.

    2000-01-01

    magnetic signature electronic design and choice of materials in packaging. The miniaturized fluxgate magnetometers had a range of 1-60000 nT with 0.1% full-scale linearity. The frequency range of interest for magnetic measurement was 10 mHz - 50 Hz. Digital data from the magnetometer's three axes were placed in a 4MB Static Random Access Memory (SRAM) in data packages (frames) formatted together with time tags and frame ID. After a specified time was elapsed, the data were Viterbi encoded and transmitted at a rate of 100 kbps (BPSK). Each of the four FFMs transmitted at different frequency. These carrier frequencies were in the range of 2200-2300 MHz. The antenna was a single patch on a high dielectric constant substrate covering one end-plate of the hockey-puck-sized unit. The local clocks aboard the FFMs were reset at the start of the mission and stayed synchronized within 3 msec during the mission. Position of each FFM with respect to the rocket is calculated by the knowledge of its release velocity (measured at exit point of the FFM launcher tract) providing an accuracy of 1 m over the maximum range of 3 km. Spatial and temporal nature of observants can be separated to within 3 m in space or 3 msec time interval.

  20. Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

    SciTech Connect

    Souers, P C; Hernandez, A; Cabacungan, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

    2008-02-05

    Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in 0 reactive flow JWL++ and Linked Cheetah V4, mostly at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. The physical basis of the input parameters is considered.

  1. Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

    SciTech Connect

    Souers, P C; Hernandez, A; Cabacungen, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

    2007-05-30

    Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in the Linked Cheetah V4.0 reactive flow code at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. A report card of 25 tests run with the same settings on LX-17 is shown, possibly the most extensive simultaneous calibration yet tried with an explosive. The physical basis of some of the input parameters is considered.

  2. A Comparison of New TATBs, FK-800 binder and LX-17-like PBXs to Legacy Materials

    SciTech Connect

    Willey, T M; DePiero, S C; Hoffman, D M

    2009-05-01

    Two newly synthesized versions of the insensitive high explosive (IHE) 1,3,5-triamino-2,4,6-trinitrobenzenes (TATBs) were compared to two legacy explosives currently used by the Department of Energy. Except for thermal analysis, small scale safety tests could not distinguish between the different synthetic routes. Morphologies of new TATBs were less faceted and more spherical. The particle size distribution of one new material was similar to legacy TATBs, but the other was very fine. Densities and submicron structure of the new TATBs were also significantly different from the legacy explosives. Pressed pellets of the new explosives were less dense. New FK-800 binder was used to prepare LX-17-like plastic bonded explosives (PBXs) from new and wet aminated TATB. Some mechanical, thermal and performance characterization of the new binder and LX-17-like PBXs was done. Significant differences were found. The reason for a number of these differences is not well understood.

  3. CHARACTERIZING DETONATING LX-17 CHARGES CROSSING A TRANSVERSE AIR GAP WITH EXPERIMENTS AND MODELING

    SciTech Connect

    Lauderbach, L M; Souers, P C; Garcia, F; Vitello, P; Vandersall, K S

    2009-06-26

    Experiments were performed using detonating LX-17 (92.5% TATB, 7.5% Kel-F by weight) charges with various width transverse air gaps with manganin peizoresistive in-situ gauges present. The experiments, performed with 25 mm diameter by 25 mm long LX-17 pellets with the transverse air gap in between, showed that transverse gaps up to about 3 mm could be present without causing the detonation wave to fail to continue as a detonation. The Tarantula/JWL{sup ++} code was utilized to model the results and compare with the in-situ gauge records with some agreement to the experimental data with additional work needed for a better match to the data. This work will present the experimental details as well as comparison to the model results.

  4. Characterization and Qualification of New TATB and Kel-F 800 for LX-17

    SciTech Connect

    Hoffman, D M; DePiero, S C

    2007-02-16

    The project would (1) compare new FK-800 with old Kel-F 800 and KF-800 lots currently available at LLNL, (2) compare and characterize new TATB with old TATB, (3) formulate new FK-800 with wet-aminated TATB and new TATBs in according to HAAP slurry coating procedure into LX-17-2, and (4) evaluate the mechanical and detonation performance characteristics of this insensitive high explosive (IHE). Priorities will be to prove that these new materials can be formulated, pressed to density and machined; and that they contain no impurities which might cause compatibility issues. Since 3M [1, 2], LANL [7], Pantex [8] and AWE [9, 10] are currently evaluating the new FK-800, we plan to share data rather than repeating their work. Our effort is briefly described: Task 1--Evaluation of newer characterization methods to identify structural variations between old and new Kel-F 800 including: Rheological and mechanical properties, copolymer content, degree of crystallinity, and interfacial interactions with TATB. Task 2--Evaluate TATBs using scattering techniques to replace sieving operations called out in the specification [12] for particle size distribution measurements. Use SEM and OM for morphological differences between the old and new explosives. Evaluate the compaction characteristics of new TATB. Task 3--Formulation of new LX-17-2 (with new FK-800 and/or new TATB) Task 4--Evaluate mechanical and performance properties of LX-17-2. At a minimum, compressive strength, dynamic mechanical behavior and a 2-inch cylinder shot should be performed and compared with existing data for LX-17-1.

  5. Development of a Detonation Profile Test for Studying Aging Effects in LX-17

    SciTech Connect

    Tran, T; Lewis, P; Tarver, C; Maienschein, J; Druce, R; Lee, R; Roeske, F

    2002-03-25

    A new small-scale Detonation Profile Test (DPT) is being developed to investigate aging effects on the detonation behavior of insensitive high explosives. The experiment involves initiating a small LX-17 cylindrical charge (12.7-19.1 mm diameter x 25.4-33 mm long) and measuring the velocity and curvature of the emerging detonation wave using a streak camera. Results for 12.7 mm diameter unconfined LX-17 charges show detonation velocity in the range between 6.79 and 7.06 km/s for parts up to 33 mm long. Since LX-17 can not sustain detonation at less than 7.3 km/s, these waves were definitely failing. Experiments with confined 12.7 mm diameter and unconfined 19.1 mm diameter samples showed wave velocities in the range of 7.4-7.6 km/s, values approaching steady state conditions at infinite diameter. Experiments with unconfined 19.1 mm diameter specimens are expected to provide reproducible and useful range of detonation parameters suitable for studying aging effects.

  6. Reacted Equation of State Experiments in LX-17 Using a Double Shock Technique

    NASA Astrophysics Data System (ADS)

    Vandersall, Kevin S.; Garcia, Frank; Tarver, Craig M.

    2011-06-01

    Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method. This method involves using 2 flyer materials on the projectile (of a known equation of state) that act to reflect a shock back into the detonated material after the initial shock. Thus, by measuring the parameters of this reflected wave, information on the reacted state can be obtained. The experiments were driven by a projectile at or above the Chapman-Jouguet (CJ) state ensuring a quick transition to detonation. Photonic Doppler Velocimetry (PDV) was used to measure the velocity profile at the interface between the LX-17 and a backing lithium fluoride (LiF) window. A discussion of this work will include the experimental setup utilized, velocimetry profiles, data interpretation, modeling, and future experiments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  7. Characterization of Detonation Wave Propagation in LX-17 Near the Critical Diameter

    SciTech Connect

    Tran, T D; Tarver, C M; Maienschein, J; Lewis, P; Pastrone, R; Lee, R S; Roeske, F

    2002-06-14

    A new Detonation Profile Test (DPT) was developed to measure simultaneously the detonation wave breakout profile and the average detonation velocity at the breakout surface. The test evaluated small cylindrical samples with diameter up to 19.08 mm and length up to 33 mm. The experiment involved initiating a LX-17 cylindrical specimen and recording the wave breakout using a fast streaking electronic camera. The initiation was done using a PBX-9407 pellet (1.630 g/cm{sup 3}), which has a Chapman-Jouguet (C-J) pressure close to that of LX-17. The acceptor breakout surface had a 2 mm wide by 1 mm deep groove that provided a step in the recorded breakout profile for velocity determination. A 532-nm laser light illuminated the specimen surface. A streak camera looking perpendicular to the groove, recorded the extinction of the laser light as the detonation wave emerged from the surface. This technique provided a high-resolution spatial and temporal profile of the wave curvature as well as accurate timing of the propagating wave over the last millimeter of the sample. The measured groove depth and recorded travel time were then used to calculate the average detonation wave velocity. Results for 12.7 mm diameter unconfined LX-17 charges showed detonation velocity in the range between 6.79 and 7.06 km/s for parts up to 33 mm long. Since LX-17 can not sustain detonation at less than 7.3 km/s , these waves were definitely failing. Experiments with confined 12.7 mm diameter and unconfined 19.1 mm diameter samples showed wave velocities in the range of 7.4-7.6 km/s, values approaching steady state conditions at infinite diameter. Both unconfined and confined charges show no sensitivity to density variations in the range between 1.890-1.915 g/cm{sup 3}. Experiments with 15.88 mm and 19.08 mm diameters gave velocities in the range between 7.2-7.45 km/s, values close to that expected for failure. The velocity measurement has an estimated experimental error in the range of 2

  8. Kick Dis Power Puck

    NASA Astrophysics Data System (ADS)

    Carlson, John E.

    2004-03-01

    There is a new toy available that can be used to demonstrate many interesting physics principles. It is called the "Kick Dis Power Puck" and is basically a round plastic hovercraft with a soft cushion material around the perimeter (Fig. 1). It is a product of the Estes Company, which is well known for their model rockets, and is available from advertisers in this journal.1,2 The puck has a diameter of 19.5 cm and comes in two colors, red or green. The two samples I purchased had masses of 307 g and 303 g, respectively. There is a forceful, built-in fan, which is run by a rechargeable battery and powers the puck for about 30 minutes. A 9-V battery charger completes the package, which sells for about 45.

  9. ALE3D Statistical Hot Spot Model Results for LX-17

    SciTech Connect

    Nichols, A L III; Tarver, C M; McGuire, E M

    2003-07-11

    The Statistical Hot Spot shock initiation and detonation reactive flow model for solid explosives in the ALE3D hydrodynamic computer code provides physically realistic descriptions of: hot spot formation; ignition (or failure to ignite); growth of reaction (or failure to grow) into surrounding particles; coalescence of reacting hot spots; transition to detonation; and self-sustaining detonation. The model has already successfully modeled several processes in HMX-based explosives, such as shock desensitization, that can not predicted by other reactive flow models. In this paper, the Statistical Hot Spot model is applied to experimental embedded gauge data on the insensitive triaminotrintrobenzene (TATB) based explosive LX-17.

  10. Vulnerability of hot LX-17 to lightning strikes on exposed detonator and actuator cables

    SciTech Connect

    Chau, H.H.; Osher, J.E.; Von Holle, W.G.; Lee, R.S.; Moua, K.

    1993-12-01

    Capacitor bank discharges with peak currents up to 700 kA were used to explode test sections of detonator cable and launch the dielectric material on top of the exploding conductor as a fast flyer plate. Velocity of the launched material, pressure profiles from the impact of the launched material and impact marks formed in aluminum witness plates were used to study the stimulus that could be transmitted to high explosive in the vicinity of the exploding cable. To quantify the risk of initiating the main charge or booster insensitive high explosive (IHE) in a weapon, one must know the threshold stimulus required for shock initiation. LX-17 samples, heated to temperatures up to 250C were impacted by 3 to 10-mm-wide stripes of 0.12-mm-thick Kapton to determine the initiation threshold velocity at ambient and elevated temperatures, The strips simulate the impact of the cover coat of a flat detonator cable which has been exploded by a lighting strike. The data allow us to assess the likelihood that a lightning strike on the cable would be able to initiate a detonation of the LX- 17 main charge.

  11. Eye injuries in Canadian amateur hockey.

    PubMed

    Pashby, T J

    1979-01-01

    Two studies, one retrospective (1972 to 1973) and one prospective (1974 to 1975), CONcerning eye injuries incurred by hockey players were conducted by the Canadian Ophthalmological Society with questionnaires to its members. Responses to the questionnaires were analyzed by age, type of injury, cause (i.e., hockey stick, puck, or other means), and results to visual acuity. The results were also designated by organized or unorganized participation. Almost 300 eye injuries were reported in each study. In the first study, 13.7% of the injured players became legally blind as a result of the injury; in the second study, 16% became legally blind. Organized hockey produced more injuries than unorganized hockey. The majority of the injuries were caused by the hockey stick. The injuries were both intraocular and extraocular. The group of 11- to 15-year olds received the highest number of injuries, and the older age group had the higher incidence of blindness. Studies have led to setting more rigid standards, altering rules of the game, and selecting face protectors for hockey players. Older players who care for their equipment prefer the plastic shield face protectors, and the younger players (who complain of fogging and scratching of the plastic) prefer mesh protectors through which neither the stick nor the puck can penetrate. New high sticking (above the shoulder level) rules were included in the 1976 official rule book for Canadian amateur hockey. PMID:474867

  12. Explosive Model Tarantula 4d/JWL++ Calibration of LX-17

    SciTech Connect

    Souers, P C; Vitello, P A

    2008-09-30

    Tarantula is an explosive kinetic package intended to do detonation, shock initiation, failure, corner-turning with dead zones, gap tests and air gaps in reactive flow hydrocode models. The first, 2007-2008 version with monotonic Q is here run inside JWL++ with square zoning from 40 to 200 zones/cm on ambient LX-17. The model splits the rate behavior in every zone into sections set by the hydrocode pressure, P + Q. As the pressure rises, we pass through the no-reaction, initiation, ramp-up/failure and detonation sections sequentially. We find that the initiation and pure detonation rate constants are largely insensitive to zoning but that the ramp-up/failure rate constant is extremely sensitive. At no time does the model pass every test, but the pressure-based approach generally works. The best values for the ramp/failure region are listed here in Mb units.

  13. Double shock experiments and reactive flow modeling on LX-17 to understand the reacted equation of state

    NASA Astrophysics Data System (ADS)

    Vandersall, Kevin S.; Garcia, Frank; Fried, Laurence E.; Tarver, Craig M.

    2014-05-01

    Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as detail on possible future experiments.

  14. Double Shock Experiments and Reactive Flow Modeling on LX-17 to Understand the Reacted Equation of State

    NASA Astrophysics Data System (ADS)

    Vandersall, Kevin; Garcia, Frank; Fried, Laurence; Tarver, Craig

    2013-06-01

    Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as possible future experiments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  15. End-Effector Development for the PIP Puck Handling Robot

    SciTech Connect

    Fowley, M.D.

    2001-01-03

    It has been decided that excess, weapons-grade plutonium shall be immobilized to prevent nuclear proliferation. The method of immobilization is to encapsulate the plutonium in a ceramic puck, roughly the size of a hockey puck, using a sintering process. This method has been officially identified as the Plutonium Immobilization Process (PIP). A Can-in-Canister storage method will be used to further immobilize the plutonium. The Can-in-Canister method uses the existing design of a Defense Waste Processing Facility (DWPF) canister to house the plutonium pucks. the process begins with several pucks being stacked in a stainless steel can. Several of the stainless steel cans are stacked in a cage-like magazine. Several of the magazines are then placed in a DWPF canister. The DWPF canister is then filled with molten glass containing high-level, radioactive waste from the DWPF vitrification process. The Can-in-Canister method makes reclamation of plutonium from the pucks technically difficult and highly undesirable. The mechanical requirements of the Can-in-Canister process, in conjunction with the amount of time required to immobilize the vast quantities of weapons-grade plutonium, will expose personnel to unnecessarily high levels of radiation if the processes were completed manually, in glove boxes. Therefore, automated equipment is designed into the process to reduce or eliminate personnel exposure. Robots are used whenever the automated handling operations become complicated. There are two such operations in the initial stages of the Can-in-Canister process, which required a six-axis robot. The first operation is a press unloading process. The second operation is a tray transfer process. To successfully accomplish the operational tasks described in the two operations, the end-effector of the robot must be versatile, lightweight, and rugged. As a result of these demands, an extensive development process was undertaken to design the optimum end-effector for these puck

  16. End-Effector Development for the PIP Puck Handling Robot

    SciTech Connect

    Fowley, M.D.

    2001-01-31

    It has been decided that excess, weapons-grade plutonium shall be immobilized to prevent nuclear proliferation. The method of immobilization is to encapsulate the plutonium in a ceramic puck, roughly the size of a hockey puck, using a sintering process. This method has been officially identified as the Plutonium Immobilization Process (PIP). A Can-in-Canister storage method will be used to further immobilize the plutonium. The Can-in-Canister method uses the existing design of a Defense Waste Processing Facility (DWPF) canister to house the plutonium pucks. the process begins with several pucks being stacked in a stainless steel can. Several of the stainless steel cans are stacked in a cage-like magazine. Several of the magazines are then placed in a DWPF canister. The DWPF canister is then filled with molten glass containing high-level, radioactive waste from the DWPF vitrification process. The Can-in-Canister method makes reclamation of plutonium from the pucks technically difficult and highly undesirable. The mechanical requirements of the Can-in-Canister process, in conjunction with the amount of time required to immobilize the vast quantities of weapons-grade plutonium, will expose personnel to unnecessarily high levels of radiation if the processes were completed manually, in glove boxes. Therefore, automated equipment is designed into the process to reduce or eliminate personnel exposure. Robots are used whenever the automated handling operations become complicated. There are two such operations in the initial stages of the Can-in-Canister process, which required a six-axis robot. The first operation is a press unloading process. The second operation is a tray transfer process. To successfully accomplish the operational tasks described in the two operations, the end-effector of the robot must be versatile, lightweight, and rugged. As a result of these demands, an extensive development process was undertaken to design the optimum end-effector for these puck

  17. Formulation and Characterization of LX-17-2 from new FK 800 binder and WA, ATK, and BAE TATBs

    SciTech Connect

    DePiero, S C; Hoffman, D M

    2007-08-03

    Currently LLNL has no Kel-F 800 or wet-aminated TATB reserves for formulation. Although both materials are soon to be commercially available, their synthesis processes have changed and the explosive must be re-evaluated. In 2000 3M phased out the uses of perfluorooctanoyl (C8) derivatives due to environmental persistence and bioaccumulation issues. A C8 derivative was used as an emulsifier for making Kel F-800. In 2001 Kel F-800 was scheduled to be discontinued and the last Kel F-800 run was made in early 2002. LANL ordered 2M$ worth of Kel-F 800 for reserves and Pantex purchased several hundred pounds to satisfy mock needs. After four years, 3M has decided to introduce a Kel-F 800-like polymer based on a new emulsifier using the same chlorotrifluoroethylene and vinylidene fluoride monomers and emulsion polymerization process. They have produced 3 batches and claim the 'new' FK-800 is indistinguishable from the 'old' Kel-F 800 in any of their testing parameters. In June-July 2006 3M scaled up a batch of about 800 pounds and have test quantities available. We have samples of the new FK-800 for evaluation. Neither wet nor dry-aminated TATB has been synthesized in the US in any significant quantity since about 1985 and significant quantities of LX-17-1 has not been formulated since about 1990. Over the last few years as part of a DOD MANTECH, ATK Thiokol and BAE Holston Army Ammunition Plant (HAAP) have produced moderate quantities of TATB ({approx}5 kg batches) with plans to scale up for DOD applications. Thiokol TATB is polycrystalline with an average particle size of about 40 m (similar to WA TATB) but HAAP TATB is only 5-6 {micro}m (similar to ultrafine). We have obtained small quantities of these materials for evaluation. The project (1) compares new FK-800 with old Kel-F 800 and FK-800 lots currently available at LLNL, (2) compares and characterizes new TATB with old TATB, (3) formulates new FK-800 with wet-aminated TATB and new TATBs in according to HAAP slurry

  18. Hockey, iPads, and Projectile Motion in a Physics Classroom

    ERIC Educational Resources Information Center

    Hechter, Richard P.

    2013-01-01

    With the increased availability of modern technology and handheld probeware for classrooms, the iPad and the Video Physics application developed by Vernier are used to capture and analyze the motion of an ice hockey puck within secondary-level physics education. Students collect, analyze, and generate digital modes of representation of physics…

  19. APPLICATION OF THE EMBEDDED FIBER OPTIC PROBE IN HIGH EXPLOSIVE DETONATION STUDIES: PBX-9502 AND LX-17

    SciTech Connect

    Hare, D; Goosman, D; Lorenz, K; Lee, E

    2006-09-26

    The Embedded Fiber Optic probe directly measures detonation speed continuously in time, without the need to numerically differentiate data, and is a new tool for measuring time-dependent as well as steady detonation speed to high accuracy. It consists of a custom-design optical fiber probe embedded in high explosive. The explosive is detonated and a refractive index discontinuity is produced in the probe at the location of the detonation front by the compression of the detonation. Because this index-jump tracks the detonation front a measurement of the Doppler shift of laser light reflected from the jump makes it possible to continuously measure detonation velocity with high spatial and temporal resolution. We have employed this probe with a Fabry-Perot-type laser Doppler velocimetry system additionally equipped with a special filter for reducing the level of non-Doppler shifted light relative to the signal. This is necessary because the index-jump signal is relatively weak compared to the return expected from a well-prepared surface in the more traditional and familiar example of material interface velocimetry. Our observations were carried out on a number of explosives but this work is focused on our results on PBX-9502 (95% TATB, 5% Kel-F) and LX-17 (92.5% TATB, 7.5% Kel-F) at varying initial charge density. Our measurements reveal a density dependence significantly lower than previous quoted values and lower than theoretical calculations. Our limited data on detonation speed dependence on wave curvature is in reasonable agreement with previous work using more standard methods and confirms deviation from the Wood-Kirkwood theoretical formula.

  20. Hockey, iPads, and Projectile Motion in a Physics Classroom

    NASA Astrophysics Data System (ADS)

    Hechter, Richard P.

    2013-09-01

    With the increased availability of modern technology and handheld probeware for classrooms, the iPad1 and the Video Physics2 application developed by Vernier are used to capture and analyze the motion of an ice hockey puck within secondary-level physics education. Students collect, analyze, and generate digital modes of representation of physics phenomena using modern technologies to complement theoretical plots. This activity acknowledges hockey players' implicit understanding of the launch angle and initial velocity of a saucer pass as basic projectile motion while engaging students in authentic physics-based problem solving.

  1. Spinal cord concussion in a professional ice hockey player.

    PubMed

    Winder, Mark J; Brett, Kelly; Hurlbert, R John

    2011-05-01

    Spinal cord concussion (SCC) is an uncommon injury resulting in transient quadriplegia. The pathophysiology of SCC has been related to underlying spinal canal stenosis in many cases, yet is not always identified. The authors present the case of a professional ice hockey player, without evidence of canal compromise, who sustained an SCC during a regulation game after being struck by a puck in the upper cervical spine. The unusual mechanism of injury is discussed along with a comprehensive review of the literature. PMID:21332276

  2. Thermopower Puck for Measurement of Thermodynamic Properties

    NASA Astrophysics Data System (ADS)

    Vargas, Andres; Fukuda, Ryan; Soliz, Nicholas; Ho, Pei-Chun

    2014-03-01

    A thermopower puck was created in order to measure the thermoelectric power and thermal conductance of strongly correlated electron materials from 10K to 300K. The puck consists of a 2k Ω resistivity heater and 2 thermometers. The heater is connected to the top of the sample and applies heat until thermal equilibrium is reached. This creates a temperature gradient across the sample and is read by the 2 thermometers, one reading the hotter temperature and the other reading the colder temperature. The wire that is used as the thermal anchor for the high temperature thermometer, which is electrically isolated from thermometer, is also used as one of the leads to measure the thermal voltage produced across the sample. To calibrate the measurement probe, the thermoelectric power and thermal conductance of a nickel sample, which was purchased from Quantum Design, was measured. The data obtained qualitatively agrees with the literature data provided to us by Quantum Design. For future work, we will be using the measurement probe to investigate the thermodynamic properties of intermetallic compounds. Research at CSU-Fresno is supported by NSF DMR-1104544. Felipe Vargas is also supported by Undergraduate Research Grant at CSU Fresno.

  3. Propagation or failure of detonation across an air gap in an LX-17 column: continuous time-dependent detonation or shock speed using the Embedded Fiber Optic (EFO) technique

    SciTech Connect

    Hare, D E; Chandler, J B; Compton, S M; Garza, R G; Grimsley, D A; Hernandez, A; Villafana, R J; Wade, J T; Weber, S R; Wong, B M; Souers, P C

    2008-01-16

    The detailed history of the shock/detonation wave propagation after crossing a room-temperature-room-pressure (RTP) air gap between a 25.4 mm diameter LX-17 donor column and a 25.4 mm diameter by 25.4 mm long LX-17 acceptor pellet is investigated for three different gap widths (3.07, 2.08, and 0.00 mm) using the Embedded Fiber Optic (EFO) technique. The 2.08 mm gap propagated and the 3.07 mm gap failed and this can be seen clearly and unambiguously in the EFO data even though the 25.4 mm-long acceptor pellet would be considered quite short for a determination by more traditional means such as pins.

  4. Remote handling in the Plutonium Immobilization Project: Puck packaging

    SciTech Connect

    Kriikku, E.

    1999-07-01

    The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP scope includes unloading transportation containers, preparing the feed streams, converting the metal feed to an oxide, adding the ceramic precursors, pressing the pucks, inspecting pucks, and sintering pucks. The PIP scope also includes loading the pucks into metal cans, sealing the cans, inspecting the cans, loading the cans into magazines, loading magazines into Defense Waste Processing Facility (DWPF) canisters, and transporting the canisters to the DWPF. The DWPF will fill the canister with a mixture of high-level waste and glass for permanent storage. Because of the radiation, remote equipment will perform PIP operations in a contained environment. The PIP puck packaging includes loading pucks into metal cans, sealing the cans, and inspecting the cans. A magnetically coupled elevator will lower a tray of pucks onto a magnetically coupled transport cart. This cart will carry the tray through an air lock into the can-loading glove box. Inside the glove box, a magnetically coupled tray lifter will raise the tray off the cart. A three-axis Cartesian robot will use a vacuum cup on a long pipe to lift the 67.3-mm (2.65-in.)-diam, 25.4-mm (1.0-in.)-tall pucks from the transfer tray and place 20 pucks in a 76.2-mm (3.0-in.)-diam stainless steel can. The Cartesian robot will place a custom hood on the open metal can, and this hood will remove the air from the can, insert helium, and place a hollow plug in the can. The SRS-developed bagless transfer system will weld the plug to the can wall and cut the can in the weld area. The can stub and the upper plug half above the cut line will remain in the sphincter seal to maintain the glove-box seal. The puck can and the lower plug half below the cut line is lowered into the bagless transfer enclosure. A floor-mounted robot in this enclosure will swipe the can exterior for contamination and place the

  5. Brain contusion with aphasia following an ice hockey injury.

    PubMed

    Degen, Ryan M; Fink, Matthew E; Callahan, Lisa; Fibel, Kenton H; Ramsay, Jim; Kelly, Bryan T

    2016-09-01

    Head injuries are relatively common in ice hockey, with the majority represented by concussions, a form of mild traumatic brain injury. More severe head injuries are rare since the implementation of mandatory helmet use in the 1960s. We present a case of a 27 year-old male who sustained a traumatic intraparenchymal hemorrhage with an associated subdural hematoma resulting after being struck by a puck shot at high velocity. The patient presented with expressive aphasia, with no other apparent neurologic deficits. Acutely, he was successfully treated with observation and serial neuroimaging studies ensuring an absence of hematoma expansion. After a stable clinical picture following 24 hours of observation, the patient was discharged and managed with outpatient speech therapy with full resolution of symptoms and return to play 3 months later. We will outline the patient presentation and pertinent points in the management of acute head injuries in athletes. PMID:27074595

  6. A Hockey Hero

    ERIC Educational Resources Information Center

    Bolduc, Matt

    2009-01-01

    In this article, the author shares the story of Will Poulos, a hockey player who has developmental and physical disabilities (mild mental retardation and left cerebral palsy). Will has overcome tremendous obstacles in his life. He was born at 28 weeks in 1986 at three pounds, one ounce, and 19 inches long. He was very sick; his odds for survival…

  7. Isolated scapula fracture: Ice hockey player without trauma

    PubMed Central

    Memişoğlu, Serdar; Yılmaz, Barış; Aktaş, Erdem; Kömür, Baran

    2015-01-01

    Introduction Scapular fractures are generally occur from in high-energy traumas and are associated with a high incidence of morbidity and mortality. Presentation of case We present an unusual scapular fracture that occurred with a rare mechanism. A 23-year-old male patient who led an active sports life for 10 years and played ice hockey for the last 5 years. In a competition, he felt a sudden pain in his right scapula after hit the puck. He did not experience any direct trauma to his shoulder and there was no evidence of any pathological fracture. The fracture was isolated in the scapular body and it was classified as type 4, according to Hardegger classification. The was patient immobilized with a Velpau bandage for three weeks and then treated with physiotherapy for shoulder rehabilitation. Discussion The fracture mechanism was likely a disharmonius contracture of the agonist and antagonist muscles of the shoulder joint while hitting the puck. Conclusion Scapular fractures are generally seen along with other injuries, but in this case we wanted to emphasize that care has to been taken to diagnose an isolated scapular fracture while assessing shoulder pain. PMID:26587232

  8. Head-Impact Mechanisms in Men's and Women's Collegiate Ice Hockey

    PubMed Central

    Wilcox, Bethany J.; Machan, Jason T.; Beckwith, Jonathan G.; Greenwald, Richard M.; Burmeister, Emily; Crisco, Joseph J.

    2014-01-01

    Context: Concussion injury rates in men's and women's ice hockey are reported to be among the highest of all collegiate sports. Quantification of the frequency of head impacts and the magnitude of head acceleration as a function of the different impact mechanisms (eg, head contact with the ice) that occur in ice hockey could provide a better understanding of this high injury rate. Objective: To quantify and compare the per-game frequency and magnitude of head impacts associated with various impact mechanisms in men's and women's collegiate ice hockey players. Design: Cohort study. Setting: Collegiate ice hockey rink. Patients or Other Participants: Twenty-three men and 31 women from 2 National Collegiate Athletic Association Division I ice hockey teams. Main Outcome Measure(s): We analyzed magnitude and frequency (per game) of head impacts per player among impact mechanisms and between sexes using generalized mixed linear models and generalized estimating equations to account for repeated measures within players. Intervention(s): Participants wore helmets instrumented with accelerometers to allow us to collect biomechanical measures of head impacts sustained during play. Video footage from 53 games was synchronized with the biomechanical data. Head impacts were classified into 8 categories: contact with another player; the ice, boards or glass, stick, puck, or goal; indirect contact; and contact from celebrating. Results: For men and women, contact with another player was the most frequent impact mechanism, and contact with the ice generated the greatest-magnitude head accelerations. The men had higher per-game frequencies of head impacts from contact with another player and contact with the boards than did the women (P < .001), and these impacts were greater in peak rotational acceleration (P = .027). Conclusions: Identifying the impact mechanisms in collegiate ice hockey that result in frequent and high-magnitude head impacts will provide us with data that may

  9. The Hockey/Art Alliance

    ERIC Educational Resources Information Center

    Wadeson, Harriet; Wirtz, Gail

    2005-01-01

    Ice hockey can be a violent sport as evidenced by the fighting among the members of an ice hockey team of 13-year-old boys from mixed racial and socioeconomic backgrounds. Two series of eight art sessions were used to help the boys develop respect for themselves and others, to solve conflicts without combat, and to build more positive…

  10. Injuries in men's international ice hockey: a 7-year study of the International Ice Hockey Federation Adult World Championship Tournaments and Olympic Winter Games

    PubMed Central

    Tuominen, Markku; Stuart, Michael J; Aubry, Mark; Kannus, Pekka; Parkkari, Jari

    2015-01-01

    Background Information on ice hockey injuries at the international level is very limited. The aim of the study was to analyse the incidence, type, mechanism and severity of ice hockey injuries in men's international ice hockey tournaments. Methods All the injuries in men's International Ice Hockey Federation World Championship tournaments over a 7-year period were analysed using a strict definition of injury, standardised reporting strategies and an injury diagnosis made by a team physician. Results 528 injuries were recorded in games resulting in an injury rate of 14.2 per 1000 player-games (52.1/1000 player-game hours). Additionally, 27 injuries occurred during practice. For WC A-pool Tournaments and Olympic Winter Games (OWG) the injury rate was 16.3/1000 player-games (59.6/1000 player-game hours). Body checking, and stick and puck contact caused 60.7% of the injuries. The most common types of injuries were lacerations, sprains, contusions and fractures. A laceration was the most common facial injury and was typically caused by a stick. The knee was the most frequently injured part of the lower body and the shoulder was the most common site of an upper body injury. Arenas with flexible boards and glass reduced the risk of injury by 29% (IRR 0.71, (95% CI 0.56 to 0.91)). Conclusions The incidence of injury during international ice hockey competition is relatively high. Arena characteristics, such as flexible boards and glass, appeared to reduce the risk of injury. PMID:25293341

  11. Plutonium Immobilization Project Can Loading and Puck Handling Vision Software

    SciTech Connect

    Kriikku, E.

    2001-09-10

    The U.S. Department of Energy will immobilize excess plutonium in the proposed Plutonium Immobilization Plant (PIP) at the Savannah River Site (SRS) as part of a two track approach for the disposition of weapons-usable plutonium. The Department of Energy is funding the development and testing effort for the PIP being conducted by Lawrence Livermore National Laboratory (LLNL), Westinghouse Savannah River Company (WSRC), Pacific Northwest National Laboratory (PNNL), and Argonne National Laboratory (ANL). The PIP will utilize the ceramic can-in-canister technology in a process that mixes plutonium and uranium with ceramic formers and neutron absorbers, presses the mixture into a ceramic puck-like form, and sinters the pucks in a furnace. Once sintered, the pucks are loaded into cans, then cans are placed into magazines, and magazines are inserted into large canisters. The canisters will subsequently be filled with high-level waste glass in the Defense Waste Processing Facility for eventual disposal in a geologic repository. The PIP project is currently being suspended due to budget constraints. The suspension requires documenting the current status of all systems under development including the Can Loading Vision System and the Puck Handling Vision System. This report provides this documentation.

  12. International Toys in Space: Hockey

    NASA Video Gallery

    Cosmonauts Sergi Treschev and Valery Korzun discover ways to adapt the game of hockey while trying to overcome the challenges of playing the game in microgravity. Astronaut Peggy Whitson narrates t...

  13. [Prospective study on injuries of the German national ice hockey teams in more than 1000 games].

    PubMed

    Gröger, A; Kuropkat, C; Mang, A; Gradinger, R

    2010-06-01

    Due to the fast and physical nature of the game, prevention of injuries is an important issue in ice hockey. The injuries of the German male senior and junior (U16, U17, U18, U19, U20) national ice hockey teams were documented and analyzed in 1006 games between 1986 and 2006. This unique long observation period over 20 years, as well as the standardized protocol of documentation provides reliable data concerning injury pattern in German international ice hockey. Overall 277 injuries were recorded. Comparing the first and the last ten years of observation, the number did not decline over the time, despite various national and international efforts of injury prevention. The majority of the injuries, almost 60%, were caused by body contact with increasing tendency. Remarkably, the injuries with no body or puck/stick contact more than doubled in the last ten years compared to the first ten years of observation. Most injuries happened to the extremities with decreasing tendency to lower body and increasing tendency to upper body injuries. The number of head injuries did not change significantly. More injuries occurred in the second and third period compared to the first period of the game. The data of this study indicate that many injuries might be due to insufficient physical condition with consecutive lack of concentration and coordination. Players do not seem to meet the increasing technical and athletic requirements of international ice-hockey. The increasing speed and physical energy in international ice-hockey make the game unique and fascinating. Therefore, the aim must be to decrease the number and above all the severity of injuries by further development and adjustment of the player's equipment. Also, a better cooperation of players, coaches, sports medicine and referees seems to be necessary for injury prevention in the future. PMID:20517801

  14. Massachusetts Special Olympics Poly Hockey.

    ERIC Educational Resources Information Center

    Morrissey, Jim

    Poly Hockey is featured in this manual of instructions for coaches and teachers to use with mentally retarded boys and girls of all ages and ability levels. It is noted that the sport has been supported by the Board of Directors of the Special Olympics and has been used in Massachusetts for over 7 years. Explained is use of the game indoors, and…

  15. Whole-body predictors of wrist shot accuracy in ice hockey: a kinematic analysis.

    PubMed

    Michaud-Paquette, Yannick; Magee, Patrick; Pearsall, David; Turcotte, René

    2011-03-01

    The purpose of this study was to identify joint angular kinematics that corresponds to shooting accuracy in the stationary ice hockey wrist shot. Twenty-four subjects participated in this study, each performing 10 successful shots on four shooting targets. An eight-camera infra-red motion capture system (240 Hz), along with passive reflective markers, was used to record motion of the joints, hockey stick, and puck throughout the performance of the wrist shot. A multiple regression analysis was carried out to examine whole-body kinematic variables with accuracy scores as the dependent variable. Significant accuracy predictors were identified in the lower limbs, torso and upper limbs. Interpretation of the kinematics suggests that characteristics such as a better stability of the base of support, momentum cancellation, proper trunk orientation and a more dynamic control of the lead arm throughout the wrist shot movement are presented as predictors for the accuracy outcome. These findings are substantial as they not only provide a framework for further analysis of motor control strategies using tools for accurate projection of objects, but more tangibly they may provide a comprehensive evidence-based guide to coaches and athletes for planned training to improve performance. PMID:21560748

  16. Visual Attentional Orienting in Developing Hockey Players.

    ERIC Educational Resources Information Center

    Enns, James T.; Richards, James C.

    1997-01-01

    Covert visual orienting was measured in 13 twelve-year-old and 11 fifteen-year-old hockey players and in 13 college students with no hockey training. Found that high-skill 15-year-olds were better able than all other groups to take advantage of the general alerting effect produced by the sudden onset of a cue. (MDM)

  17. The High School Players Field Hockey Journal.

    ERIC Educational Resources Information Center

    Schultz, Bobbie

    This student's journal aims at helping to develop a successful and highly motivated high school girls field hockey team. General information about the sport and student involvement is presented. Definitions of terms used in field hockey are given as well as general considerations about play, defensive and offensive strategies, and penalties.…

  18. The Open Geospatial Consortium PUCK Standard: Building Sensor Networks with Self-Describing Instruments

    NASA Astrophysics Data System (ADS)

    O'Reilly, T. C.; Broering, A.; del Rio, J.; Headley, K. L.; Toma, D.; Bermudez, L. E.; Edgington, D.; Fredericks, J.; Manuel, A.

    2012-12-01

    Sensor technology is rapidly advancing, enabling smaller and cheaper instruments to monitor Earth's environment. It is expected that many more kinds and quantities of networked environmental sensors will be deployed in coming years. Knowledge of each instrument's command protocol is required to operate and acquire data from the network. Making sense of these data streams to create an integrated picture of environmental conditions requires that each instrument's data and metadata be accurately processed and that "suspect" data be flagged. Use of standards to operate an instrument and retrieve and describe its data generally simplifies instrument software development, integration, operation and data processing. The Open Geospatial Consortium (OGC) PUCK protocol enables instruments that describe themselves in a standard way. OGC PUCK defines a small "data sheet" that describes key instrument characteristics, and a standard protocol to retrieve the data sheet from the device itself. Data sheet fields include a universal serial number that is unique across all PUCK-compliant instruments. Other fields identify the instrument manufacturer and model. In addition to the data sheet, the instrument may also provide a "PUCK payload" which can contain additional descriptive information (e.g. a SensorML document or IEEE 1451 TEDS), as well as actual instrument "driver" code. Computers on the sensor network can use PUCK protocol to retrieve this information from installed instruments and utilize it appropriately, e.g. to automatically identify, configure and operate the instruments, and acquire and process their data. The protocol is defined for instruments with an RS232 or Ethernet interface. OGC members recently voted to adopt PUCK as a component of the OGC's Sensor Web Enablement (SWE) standards. The protocol is also supported by a consortium of hydrographic instrument manufacturers and has been implemented by several of them (https://sites.google.com/site/soscsite/). Thus far

  19. Field Hockey-Lacrosse Guide. June 1974-June 1976.

    ERIC Educational Resources Information Center

    Ramser, Frances, Ed.; Bixler, Agnes, Ed.

    This guide is a collection of essays by various authors on field hockey and lacrosse. There is a separate section for each sport. The topics covered in the field hockey section include half-time coaching, visual aids, umpiring techniques and ratings, goalkeeper training, experimental field hockey rules, and the code of rules for the game of hockey…

  20. Injuries in women's ice hockey: special considerations.

    PubMed

    Abbott, Kristin

    2014-01-01

    Ice hockey is a popular collision sport with a growing number of female athletes participating each year. As participation among girls and women continues to increase, it will be important to recognize common injuries occurring during women's games. Despite difference in the rules that prohibit body checking in women's and girls' games, injury profiles are similar to those of their male counterparts. Concussions, contusions, acromioclavicular joint injuries, ligamentous knee injuries, and muscle strains occur during women's ice hockey games, with groin strains accounting for the most common practice injury. This article will review both injury rates and common injuries occurring in women's ice hockey, with a focus on the observed concussion rate and groin injuries. PMID:25391093

  1. Explanatory style among elite ice hockey athletes.

    PubMed

    Davis, H; Zaichkowsky, L

    1998-12-01

    Mentally tough' athletes show resilience and an ability to compete during adverse conditions. The present study investigated mental toughness and assessed causal explanations for positive and negative reactions to imagined events using Seligman's Attributional Style Questionnaire. Pessimistic Explanatory style on this scale is a risk factor for negative affect and behavior following negative events. 38 elite athletes in ice hockey were rated for mental toughness by the National Hockey League's scouts on consensually derived criteria. The comparison of players above and below the median split on mental toughness showed composite explanations for negative events that were more internal, stable and global for players above the median. Contrary to predictions, these results suggest that a Pessimistic Explanatory style may benefit hockey performance. PMID:9885080

  2. Hockey: Special Olympics Sports Skills Instructional Program.

    ERIC Educational Resources Information Center

    Special Olympics, Inc., Washington, DC.

    Suggestions for coaching and teaching hockey skills to mentally retarded persons are presented in this guide, one of seven booklets on Special Olympics Sports Skills Instructional Programs. An introductory section presents an overview of the sport, information on the organization of the training session, and a list of goals, objectives, and…

  3. Hockey STAR: A Methodology for Assessing the Biomechanical Performance of Hockey Helmets.

    PubMed

    Rowson, Bethany; Rowson, Steven; Duma, Stefan M

    2015-10-01

    Optimizing the protective capabilities of helmets is one of several methods of reducing brain injury risk in sports. This paper presents the experimental and analytical development of a hockey helmet evaluation methodology. The Summation of Tests for the Analysis of Risk (STAR) formula combines head impact exposure with brain injury probability over the broad range of 227 head impacts that a hockey player is likely to experience during one season. These impact exposure data are mapped to laboratory testing parameters using a series of 12 impact conditions comprised of three energy levels and four head impact locations, which include centric and non-centric directions of force. Injury risk is determined using a multivariate injury risk function that incorporates both linear and rotational head acceleration measurements. All testing parameters are presented along with exemplar helmet test data. The Hockey STAR methodology provides a scientific framework for manufacturers to optimize hockey helmet design for injury risk reduction, as well as providing consumers with a meaningful metric to assess the relative performance of hockey helmets. PMID:25822907

  4. Hockey sticks, principal components, and spurious significance

    NASA Astrophysics Data System (ADS)

    McIntyre, Stephen; McKitrick, Ross

    2005-02-01

    The ``hockey stick'' shaped temperature reconstruction of Mann et al. (1998, 1999) has been widely applied. However it has not been previously noted in print that, prior to their principal components (PCs) analysis on tree ring networks, they carried out an unusual data transformation which strongly affects the resulting PCs. Their method, when tested on persistent red noise, nearly always produces a hockey stick shaped first principal component (PC1) and overstates the first eigenvalue. In the controversial 15th century period, the MBH98 method effectively selects only one species (bristlecone pine) into the critical North American PC1, making it implausible to describe it as the ``dominant pattern of variance''. Through Monte Carlo analysis, we show that MBH98 benchmarks for significance of the Reduction of Error (RE) statistic are substantially under-stated and, using a range of cross-validation statistics, we show that the MBH98 15th century reconstruction lacks statistical significance.

  5. Seasonal Mood Disturbances in Collegiate Hockey Players

    PubMed Central

    Rosen, Lionel W.; Shafer, Christine L.; Smokler, Carol; Carrier, David; McKeag, Douglas B.

    1996-01-01

    Objective: The purpose of this paper is to: 1) describe the seasonal affective disorder syndrome using a case illustration, 2) provide a simple and reliable method for identifying seasonal affective disorder, and 3) provide data as to the prevalence of the syndrome in a subset of collegiate hockey players. Design and Setting: Collegiate hockey players were selected, because their practices begin in the fall and play is completed in the spring. The teams selected for participation were from the far Northwest and the upper Midwest regions. Subjects: Sixty-eight Division I hockey players volunteered for the study. The three teams from which the subjects were chosen were located above latitude 42°/45' north. Subjects were from the northern latitudes. Measurements: The Seasonal Pattern Assessment Questionnaire was used to screen for seasonality. A sample of the athletes was also examined using the Hamilton Rating Scale for Depression together with the Diagnostic and Statistical Manual of Mental Disorders (4th ed) criteria for Seasonal Pattern Specifier. Results: Thirty-three (51%) were asymptomatic, 7 (11%) met the criteria for seasonal affective disorder, and 25 (39%) hockey players scored in the range that could classify them as candidates for subsyndromal seasonal affective disorder. Conclusions: The prevalence of seasonal affective disorder among our sample approximated the national norm for the northern latitudes. However, the prevalence of subsyndromal seasonal affective disorder in our population was 25% compared to 13% reported nationally. Light therapy has been shown to reverse the effects of the disorders; however, further research needs to be conducted to determine its acceptance and effectiveness by the athletic population. PMID:16558403

  6. Miniature Videoprobe Hockey Stick Delivery System

    SciTech Connect

    Hale, Lester R.; McMurry, Kyle M.

    1998-06-18

    The present invention is a miniature videoprobe system having a probe termination box, a strong back, and a videoprobe housing. The videoprobe system is able to obtain images from a restricted space at least as small as 0.125 inches while producing a high quality image. The strong back has a hockey stick shape with the probe termination box connecting to the top of the handle-like portion of the hockey stick and the videoprobe housing attaching to the opposite end or nose of the hockey stick shape. The videoprobe housing has a roughly arrowhead shape with two thin steel plates sandwiching the internal components there between. The internal components are connected in series to allow for a minor dimension of the videoprobe housing of 0.110 inches. The internal components include an optics train, a CCD chip, and an electronics package. An electrical signal is transmitted from the electronics package through wiring within an internal channel of the strong back to the probe termination box. The strong back has milled into it multiple internal channels for facilitating the transfer of information, items, or devices between the probe termination box and the videoprobe housing.

  7. The Ice Hockey Injury: A Case Study in Physiology

    ERIC Educational Resources Information Center

    Stephens, Phil

    2004-01-01

    A high school hockey team is playing the last of three games in one day. The game gets rough, and the star player is slammed against the boards. Injured, he is escorted off the ice. This case follows his health as it deteriorates over the next several hours. Students are presented with the hockey player's symptoms, and they use their knowledge of…

  8. 11. Photocopy of Photograph (Courtesy of the Detroit Hockey Club, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photocopy of Photograph (Courtesy of the Detroit Hockey Club, Detroit, Michigan). GROUNDBREAKING FOR ADDITION, JUNE 23, 1965. Left Sid Abel, Genral Manager of the Detroit Hockey Club Center - Jerome Cavanaugh, Mayor, City of Detroit Right - Nick Landis, General Manager of the Olympia Stadium - Olympia Arena, 5920 Grand River Avenue, Detroit, MI

  9. Floor Hockey---Is It a Safe Sport for Schools?

    ERIC Educational Resources Information Center

    Gray, Gary R.

    1989-01-01

    Guidelines under which floor hockey should be taught to prevent avoidable injuries are presented. Three court cases involving floor hockey related injuries are reviewed, and issues of responsibility and liability on the part of physical educators and schools are discussed. (IAH)

  10. Benthic re-colonization in post-dredging pits in the Puck Bay (Southern Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Szymelfenig, Maria; Kotwicki, Lech; Graca, Bożena

    2006-07-01

    The stage of benthic re-colonization at a site formed by sand extraction was investigated some 10 years after the cessation of dredging. The examined post-dredging pit is one of five deep (up to 14 m) pits created with a static suction hopper on the sandy, flat and shallow (1-2 m) part of the inner Puck Bay (the southern Baltic Sea). The topography of the dredged area makes a specific trap for different kinds of organic matter. It is created by the small areas of post-dredging pits as compared to their depths. As a result, organic matter accumulation leads to anaerobic conditions and hydrogen sulfide formation. Macrofauna was not found to occur permanently in the deepest part (11 m) of the cup-shaped depression, which was characterized by its small area (0.2 km 2) and steep walls. However, permanent occurrence of meiofauna (max. 180 ind. 10 cm -2, mainly Nematoda) was noted. Undoubtedly, re-colonization of benthic fauna assemblages, typical of shallow and sandy seabed of the Puck Bay, will not follow in a natural way in the area of post-dredging pits. Also, it could not be expected that the re-colonization sequence would result in the formation of a structure similar to that of the natural depression (the Kuźnica Hollow).

  11. Biceps femoris tendon injuries sustained while playing hockey

    PubMed Central

    Watura, Christopher; Harries, William

    2011-01-01

    A 42-year-old female nurse presented in March 2008 with a left proximal hamstring tendon injury sustained while playing hockey. At surgery, the proximal biceps femoris tendon and semitendonosus were found to be ruptured and were repaired. The patient made a good recovery but sustained a further hockey injury in January 2010 involving a complete tear and rupture of the biceps femoris tendon distally. This was managed conservatively and the patient was able to return to playing hockey 10 months later. Biceps femoris tendon injuries have been reported in sport but this is the first documented case of the injury occurring while playing hockey and is also the first reported case of a biceps tendon rupture proximally (hamstring tendon) followed by distal biceps femoris rupture at the knee in the same leg. PMID:22715185

  12. Gender, Sport, and the Construction of Community: A Case Study from Women's Ice Hockey.

    ERIC Educational Resources Information Center

    Theberge, Nancy

    1995-01-01

    Examines the construction of community on a women's ice hockey team, using data from fieldwork and interviews with one Canadian team. Results indicated that the locker room provided a space where players came together as hockey players and women. A common focus on hockey united the diverse group. (SM)

  13. Field Hockey-Lacrosse Guide with Official Rules. June 1972 - June 1974.

    ERIC Educational Resources Information Center

    Thornburg, Mary Lou, Ed.; Pitts, Jackie, Ed.

    Rules for women's field hockey and lacrosse from June 1972 to June 1974 are discussed. Standards in sports for girls and women are detailed as is the Division for Girls and Women's Sports (DGWS) statement of beliefs. Specific articles on field hockey techniques, skills, services available through the United States Field Hockey Association, rules,…

  14. PUCK: An Automated Prompting System for Smart Environments: Towards achieving automated prompting; Challenges involved.

    PubMed

    Das, Barnan; Cook, Diane J; Schmitter-Edgecombe, Maureen; Seelye, Adriana M

    2012-10-01

    The growth in popularity of smart environments has been quite steep in the last decade and so has the demand for smart health assistance systems. A smart home-based prompting system can enhance these technologies to deliver in-home interventions to users for timely reminders or brief instructions describing the way a task should be done for successful completion. This technology is in high demand given the desire of people who have physical or cognitive limitations to live independently in their homes. In this paper, with the introduction of the "PUCK" prompting system, we take an approach to automate prompting-based interventions without any predefined rule sets or user feedback. Unlike other approaches, we use simple off-the-shelf sensors and learn the timing for prompts based on real data that is collected with volunteer participants in our smart home test bed. The data mining approaches taken to solve this problem come with the challenge of an imbalanced class distribution that occurs naturally in the data. We propose a variant of an existing sampling technique, SMOTE, to deal with the class imbalance problem. To validate the approach, a comparative analysis with Cost Sensitive Learning is performed. PMID:25364323

  15. Seagrass vegetation and meiofauna enhance the bacterial abundance in the Baltic Sea sediments (Puck Bay).

    PubMed

    Jankowska, Emilia; Jankowska, Katarzyna; Włodarska-Kowalczuk, Maria

    2015-09-01

    This study presents the first report on bacterial communities in the sediments of eelgrass (Zostera marina) meadows in the shallow southern Baltic Sea (Puck Bay). Total bacterial cell numbers (TBNs) and bacteria biomass (BBM) assessed with the use of epifluorescence microscope and Norland's formula were compared between bare and vegetated sediments at two localities and in two sampling summer months. Significantly higher TBNs and BBM (PERMANOVA tests, P < 0.05) were recorded at bottom covered by the seagrass meadows in both localities and in both sampling months. The relationships between bacteria characteristics and environmental factors (grain size, organic matter, photopigments in sediments), meiofauna and macrofauna densities, as well as macrophyte vegetation characteristics (shoot density, phytobenthos biomass) were tested using PERMANOVA distance-based linear model (DISTLM) procedures and showed that the main factors explaining bacteria characteristics are bottom type (vegetated vs. unvegetated) and meiofauna density. These two factors explained together 48.3% of variability in TBN and 40.5% in BBM, and their impacts did not overlap (as indicated by DISTLM sequential tests) demonstrating the different natures of these relationships. The effects of seagrass were most probably related to the increase of organic matter and providing habitat while higher numbers of meiofauna organisms may have stimulated the bacterial growth by increased grazing. PMID:26178839

  16. Are There Differences in Ice Hockey Injuries Between Sexes?

    PubMed Central

    MacCormick, Lauren; Best, Thomas M.

    2014-01-01

    Background: Men’s ice hockey allows for body checking, and women’s ice hockey prohibits it. Studies have reported injury data on both sexes, but no systematic reviews have compared the injury patterns between male and female ice hockey players. Hypothesis: Men’s and women’s ice hockey would have different types of injuries, and this difference would extend across the different age groups and levels of play. Study Design: Systematic review; Level of evidence, 4. Methods: Three databases, 3 scientific journals, and selected bibliographies were searched to identify articles relevant to this study. Articles were further screened by the use of predetermined inclusion and exclusion criteria. Twenty-two studies met these criteria and were subsequently reviewed. Results: Men sustained higher rates of injuries than women at all age levels, and both sexes sustained at least twice as many injuries in games than practices. Both sexes sustained most of their injuries from player contact. Men and women in college sustained most injuries to the head and face, and women suffered from higher percentages of concussion. At all ages and levels of play, men had higher rates of upper extremity injuries (shoulder), while women were found to sustain more injuries to the lower extremity (thigh, knee). Conclusion: Although findings showed men sustaining higher rates of injuries than women, the predominant mechanism of player contact was the same. The most common locations and types of injuries in female ice hockey players are comparable to other sports played by women, and similar interventions could offer protection against injury. Clinical Relevance: Further studies that report injury data for women playing ice hockey at all levels will assist in understanding what prevention strategies should be implemented. PMID:26535265

  17. Increasing task complexity and ice hockey skills of youth athletes.

    PubMed

    Fait, Philippe E; McFadyen, Bradford J; Zabjek, Karl; Reed, Nick; Taha, Tim; Keightley, Michelle

    2011-02-01

    The objective of this pilot study was to investigate the effects on cognitive performance of progressively adding tasks specific to ice hockey (skating, stick handling, and obstacle avoidance) during a visual interference task (Stroop Color Word Test-interference condition). In addition, the effects on locomotor performance of progressively adding tasks of stickhandling, visual interference, and obstacle avoidance related to maximal skating speed and minimal obstacle clearance were investigated in eight male athletes ages 10 to 12 years. Results revealed decreased performance on both cognitive and physical measures with increased task complexity, suggesting that adding complexity to an environment influences hockey skill performance. PMID:21466078

  18. Asymmetry in body composition in female hockey players.

    PubMed

    Krzykała, M; Leszczyński, P

    2015-08-01

    The aim of the study was to determine if a sport in which one side of the body is dominant, like field hockey, influences regional body composition and bone mineral density (BMD) distribution in particular body segments, and whether the sporting level is a determining factor. Dual energy X-ray absorptiometry (DXA) method (Lunar Prodigy Advance; General Electric, Madison, USA) with the whole body scan was used to measure bone mineral density, fat mass and lean mass in 31 female field hockey players divided according to their sporting level. The morphological asymmetry level was assessed between two body sides and body segments in athletes from the National Team (n=17) and from the Youth Team (n=14) separately and between groups. Bone mineral density in the lower extremity and of the trunk was significantly asymmetric in favor of the left side in the National Team. In the case of the Youth Team, only the trunk BMD indicated clear left-right difference with left side dominance. Both the lean mass and fat mass values were relatively higher on the left side of all body segments and it related to both analyzed groups of athletes. The present study shows that playing field hockey contributes to laterality in body composition and BMD and that the sporting level is a determining factor. In most cases the left side dominated. A greater asymmetry level was observed in more experienced female field hockey players. PMID:26077573

  19. A Hockey Night in Canada: An Imagined Conversation between Theorists

    ERIC Educational Resources Information Center

    Fogel, Curtis

    2010-01-01

    In this paper, various methodological issues surrounding the sociological study of sport are explored. Through an imagined dialogue between two graduate students at a hockey game, this work brings together three divergent approaches to social enquiry: Positivist Grounded Theory, Constructivist Grounded Theory, and Actor-Network Theory. This paper…

  20. Field Hockey; Lacrosse, June 1976-June 1978. NAGWS Guide.

    ERIC Educational Resources Information Center

    Nixon, Linda K., Ed.; Hess, Eleanor Kay, Ed.

    This guide for field hockey and lacrosse is one in a series of guides for 22 sports published by the National Association for Girls and Women in Sport (NAGWS). Guides contain information on NAGWS-approved playing rules, officials' ratings, articles on teaching, coaching and organization, regulations governing national championships,…

  1. Injuries in Youth Hockey. On-Ice Emergency Care.

    ERIC Educational Resources Information Center

    Blanchard, Bradford M.; Castaldi, Cosmo R.

    1991-01-01

    Reviews the nature and frequency of injuries in youth hockey (which range from musculoskeletal injuries to life-threatening emergencies). Overall injury rates have decreased, but there is an increase in head, neck, and spine injuries. Those injuries that are serious demand prompt, skillful attention. A comprehensive format for on-ice management is…

  2. Injury data of major international field hockey tournaments

    PubMed Central

    Theilen, Till-Martin; Mueller-Eising, Wiebke; Wefers Bettink, Peter; Rolle, Udo

    2016-01-01

    Background Detailed injury data are not available for international tournaments in field hockey. We investigated the epidemiology of field hockey injuries during major International Hockey Federation (Fédération Internationale de Hockey, FIH) tournaments in 2013. Materials and methods FIH injury reports were used for data collection. All major FIH tournaments for women (n=5) and men (n=11) in 2013 were included. The main focus of this study was to assess the pattern, time, site on the pitch, body site and mechanism of each of the injuries. We calculated the average number of injuries per match and the number of injuries per 1000 player match hours. Results The average number of injuries was 0.7 (95% CI 0.5 to 1.0) per match in women's tournaments and 1.2 (95% CI 0.8 to 1.7) per match in men's tournaments. The number of injuries per 1000 player match hours ranged from 23.4 to 44.2 (average 29.1; 95% CI 18.6 to 39.7) in women and 20.8 to 90.9 (average 48.3; 95% CI 30.9 to 65.8) in men. Most injuries occurred in the circle (n=25, 50%, in women, n=95, 51%, in men). The rate of injuries increased after the first quarter. Injuries to the head and face (n=20, 40%) were most common in women. The head/face (n=51, 27%) and the thigh/knee (n=52, 28%) were equally affected in men. The ball caused the most injuries, followed by the stick, collisions and tripping/falling. There were no deaths or injuries that required hospital treatment in the entire cohort. Summary Field hockey has a low incidence of acute injuries during competition. PMID:26246418

  3. Hypothenar hammer syndrome from ice hockey stick-handling.

    PubMed

    Zayed, Mohamed A; McDonald, Joey; Tittley, Jacques G

    2013-11-01

    Ulnar artery thrombosis and hypothenar hammer syndrome are rare vascular complications that could potentially occur with repeated blows or trauma to the hand. Although initially reported as an occupational hazard among laborers and craftsmen, it has been observed more recently among recreationalists and athletes. Until now, it has never been reported as a complication in ice hockey players. In this case report, a 26-year-old Canadian professional ice hockey player presented with acute dominant right hand paleness, coolness, and pain with hand use. The patient used a wooden hockey stick with a large knob of tape at the end of the handle, which he regularly gripped in the palm of his right hand to help with face-offs and general stick-handling. Sonographic evaluation demonstrated no arterial flow in the distal right ulnar artery distribution, and ulnar artery occlusion with no aneurysmal degeneration was confirmed by magnetic resonance angiogram. Intraarterial thrombolytic therapy was initiated, and subsequent serial angiograms demonstrated significant improvement in distal ulnar artery flow as well as recanalization of right hand deep palmar arch and digital arteries. The patient's symptoms resolved, and he was maintained on therapeutic anticoagulation for 3 months prior to returning to playing ice hockey professionally, but with a padded glove and no tape knob at the handle tip. This case highlights a unique presentation of hockey stick-handling causing ulnar artery thrombosis that was likely from repeated palmar hypothenar trauma. Appropriate diagnostic imaging, early intraarterial thrombolysis, and postoperative surveillance and follow-up were crucial for the successful outcome in this patient. PMID:23988538

  4. Expert-novice differences in brain function of field hockey players.

    PubMed

    Wimshurst, Z L; Sowden, P T; Wright, M

    2016-02-19

    The aims of this study were to use functional magnetic resonance imaging to examine the neural bases for perceptual-cognitive superiority in a hockey anticipation task. Thirty participants (15 hockey players, 15 non-hockey players) lay in an MRI scanner while performing a video-based task in which they predicted the direction of an oncoming shot in either a hockey or a badminton scenario. Video clips were temporally occluded either 160 ms before the shot was made or 60 ms after the ball/shuttle left the stick/racquet. Behavioral data showed a significant hockey expertise×video-type interaction in which hockey experts were superior to novices with hockey clips but there were no significant differences with badminton clips. The imaging data on the other hand showed a significant main effect of hockey expertise and of video type (hockey vs. badminton), but the expertise×video-type interaction did not survive either a whole-brain or a small-volume correction for multiple comparisons. Further analysis of the expertise main effect revealed that when watching hockey clips, experts showed greater activation in the rostral inferior parietal lobule, which has been associated with an action observation network, and greater activation than novices in Brodmann areas 17 and 18 and middle frontal gyrus when watching badminton videos. The results provide partial support both for domain-specific and domain-general expertise effects in an action anticipation task. PMID:26674059

  5. SnapShot: Visualization to Propel Ice Hockey Analytics.

    PubMed

    Pileggi, H; Stolper, C D; Boyle, J M; Stasko, J T

    2012-12-01

    Sports analysts live in a world of dynamic games flattened into tables of numbers, divorced from the rinks, pitches, and courts where they were generated. Currently, these professional analysts use R, Stata, SAS, and other statistical software packages for uncovering insights from game data. Quantitative sports consultants seek a competitive advantage both for their clients and for themselves as analytics becomes increasingly valued by teams, clubs, and squads. In order for the information visualization community to support the members of this blossoming industry, it must recognize where and how visualization can enhance the existing analytical workflow. In this paper, we identify three primary stages of today's sports analyst's routine where visualization can be beneficially integrated: 1) exploring a dataspace; 2) sharing hypotheses with internal colleagues; and 3) communicating findings to stakeholders.Working closely with professional ice hockey analysts, we designed and built SnapShot, a system to integrate visualization into the hockey intelligence gathering process. SnapShot employs a variety of information visualization techniques to display shot data, yet given the importance of a specific hockey statistic, shot length, we introduce a technique, the radial heat map. Through a user study, we received encouraging feedback from several professional analysts, both independent consultants and professional team personnel. PMID:26357191

  6. THE COMPETITIVE DEMANDS OF ELITE MALE RINK HOCKEY

    PubMed Central

    Del Valle, M.E.; Egocheaga, J.; Linnamo, V.; Fernández, A.

    2013-01-01

    The aim of this study was to simulate the activity pattern of rink hockey by designing a specific skate test (ST) to study the energy expenditure and metabolic responses to this intermittent high-intensity exercise and extrapolate the results from the test to competition. Six rink hockey players performed, in three phases, the 20-metre multi-stage shuttle roller skate test, a tournament match and the ST. Heart rate was monitored in all three phases. Blood lactate, oxygen consumption, ventilation and respiratory exchange ratio were also recorded during the ST. Peak HR was 190.7±7.2 beats · min−1. There were no differences in peak HR between the three tests. Mean HR was similar between the ST and the match (86% and 87% of HRmax, respectively). Peak and mean ventilation averaged 111.0±8.8 L · min−1 and 70.3±14.0 L · min−1 (60% of VEmax), respectively. VO2max was 56.3±8.4 mL · kg−1 · min−1, and mean oxygen consumption was 40.9±7.9 mL · kg−1 · min−1 (70% of VO2max). Maximum blood lactate concentration was 7.2±1.3 mmol · L-1. ST yielded an energy expenditure of 899.1±232.9 kJ, and energy power was 59.9±15.5 kJ · min−1. These findings suggest that the ST is suitable for estimating the physiological demands of competitive rink hockey, which places a heavy demand on the aerobic and anaerobic systems, and requires high energy consumption. PMID:24744488

  7. Playing Hockey, Riding Motorcycles, and the Ethics of Protection

    PubMed Central

    2012-01-01

    Ice hockey and motorcycle riding are increasingly popular activities in the United States that are associated with high risks of head and facial injuries. In both, effective head and facial protective equipment are available. Yet the debates about safety policies regarding the use of head protection in these activities have taken different forms, in terms of the influence of epidemiological data as well as of the ethical concerns raised. I examine these debates over injury prevention in the context of leisure activities, in which the public health duty to prevent avoidable harm must be balanced with the freedom to assume voluntary risks. PMID:23078472

  8. Self-esteem and injury in competitive field hockey players.

    PubMed

    Kolt, G S; Roberts, P D

    1998-08-01

    A volunteer sample of 50 competitive field hockey players completed the Coopersmith Self-esteem Inventory at pre- and postseason and prospectively collected injury data over a 20-wk. season. Multiple regression analysis showed no relationship between scores on Self-esteem and the number of injuries, the participation time affected due to injury, and sex of players. Further multiple regression analysis showed that frequency of the more severe injuries significantly predicted scores on Self-esteem. This finding can be interpreted as evidence of the relationship between low self-esteem and injury in sport. PMID:9760670

  9. PHYSICAL THERAPY MANAGEMENT OF ICE HOCKEY ATHLETES: FROM THE RINK TO THE CLINIC AND BACK

    PubMed Central

    Davenport, Todd E.

    2016-01-01

    ABSTRACT Background The increasing number of athletes playing hockey compels rehabilitation professionals working in orthopedic and sports settings to understand the unique functional demands of ice hockey and the patterns of injuries they may promote. Purpose The purpose of this clinical perspective is to: (1) discuss the functional implications of different positions and age levels on injury prevalence within the sport; (2) summarize the seven most common injuries sustained by ice hockey athletes; and (3) present a conceptual model for the clinical management and prevention of these injuries by rehabilitation professionals. Methods A narrative review and synthesis was conducted of currently available literature on prevalence, etiology, rehabilitative intervention, prognosis, and prevention of ice hockey injuries. Results Research evidence is available to support the prevalence of injuries sustained while participating in ice hockey, as well as the most effective clinical treatment protocols to treat them. Most of the existing protocols are based on clinical and sports experience with incorporation of scientific data. Conclusion This clinical commentary reviews the current concepts of ice hockey injury care and prevention, based on scientific information regarding the incidence, mechanism, rehabilitation protocols, prognosis, and prevention of injuries. Science-based, patient-centered reasoning is integral to provide the highest quality of rehabilitative and preventative care for ice hockey athletes by physical therapists. Level of Evidence 5 PMID:27274432

  10. Ice Hockey Injuries in a Japanese Elite Team: A 3-Year Prospective Study

    PubMed Central

    Kuzuhara, Kenji; Shimamoto, Hideki; Mase, Yasuyoshi

    2009-01-01

    Context: As the Asian Ice Hockey League gradually expands and becomes more competitive, ice hockey-related injuries may increase. However, no reports have been published on ice hockey injuries in Japan, including the method of injury and the daily supervision of the players during the regular season. Objective: To prospectively study the incidence, types, and mechanisms of ice hockey injuries in an elite Japanese ice hockey team. Design: Prospective observational cohort study design. Setting: An elite ice hockey team, Tokyo, Japan. Patients or Other Participants: Ninety-four players during the 2002–2005 seasons. Main Outcome Measure(s): Data were collected for 3 consecutive seasons using an injury reporting form. Results: The overall game injury rate was 74.3 per 1000 player-game hours and 11.7 per 1000 player-game hours for injuries resulting in any time loss. The overall practice injury rates were 11.2 per 1000 player-practice hours and 1.1 per 1000 player-practice hours for injuries resulting in any time loss. Forwards had the highest rate of injury, followed by defensemen and then goalkeepers. Contusions were the most common injury, followed by strains, lacerations, and sprains. Conclusions: Most injuries among Japanese ice hockey players occurred during games. Game or play intensity may influence the injury rate during games. PMID:19295967

  11. Physical demands and physiological responses during elite field hockey.

    PubMed

    Lythe, J; Kilding, A E

    2011-07-01

    The aim of this study was to determine the physical demands of elite men's field hockey using modern time-motion analysis techniques. 18 elite male players (age: 24.4 ± 4.5 yrs) participated in 5 matches, during which physical outputs of players were quantified using GPS units and heart rate monitors. The mean total distance covered by each individual player was 6798 ± 2009 m. Mean total distance covered per position for 70 min (position (70)) was 8160 ± 428 m. Distance covered per position (70) decreased by 4.8% between the 1 (st )and 2 (nd) halves ( P < 0.05). Fullbacks covered significantly less total distance than all other positions ( P < 0.05). High-intensity running (>19 km.h (-1)) comprised 6.1% (479 ± 108 m) of the total distance covered and involved 34 ± 12 sprints per player, with an average duration of 3.3 s. Average HR was higher in the 1 (st) half (86.7% HR (max)) than the 2 (nd) half, (84.4% HR (max)), though this was not significant ( P = 0.06). The results suggest that modern day elite field hockey is a physically demanding team sport. Quantification of the demands and outputs of players at this level provides a useful framework on which to develop conditioning practices. The difference in physical outputs observed for some positions suggests position-specific conditioning is required at the elite level. PMID:21563026

  12. Checking in: an analysis of the (lack of) body checking in women's ice hockey.

    PubMed

    Weaving, Charlene; Roberts, Samuel

    2012-09-01

    Despite the growing popularity of women's ice hockey in North America, players continue to face limitations because of the prohibition of body checking. In this paper we argue from a liberal feminist philosophical perspective that this prohibition reinforces existing traditional stereotypes of female athletes. Because the women's game does not incorporate checking, female ice hockey players are not afforded the same opportunity to flourish as men and experience bodily agency, which results in continued male domination of the game, therefore, indirectly reinforcing a gender hierarchy in hockey and society. PMID:22978197

  13. Sports chiropractic management at the World Ice Hockey Championships

    PubMed Central

    2010-01-01

    Background Ice hockey is an international sport. Injuries occur in a full body fashion, to a number of tissues, commonly through body contact. There is a lack of literature documenting the scope of sports chiropractic practice. Thus, it was the aim to document the type, scope and severity of conditions presenting to, and the treatment provided by, the New Zealand team chiropractor acting as a primary health provider for the duration of the 2007 World Ice Hockey Championships. Methods All conditions presenting were recorded. Diagnosis was recorded along with clinical parameters of injury: injury type, severity, mechanism and whether referral or advanced imaging was required. All treatment provided was continuously recorded, including information on the number of treatments required and the reason, duration, type and location of treatment. Results Players presented for diagnosis of injury 50 times. Muscle (34%), joint (24%) and tendon injuries (18%) were most common. Players presented with a new injury 76% of the time. Most injuries had been present for less than one week (84%), with 53% occurring through a contact mechanism. Injuries were common at training and match locations. Only two injuries required the player to stop playing or training, both of which were referred for advanced imaging. During the study, 134 treatment consultations were rendered to 45 player injuries. Eighty per-cent of injuries were managed with four or less treatments. Three quarters of treatment was provided at training locations with treatment duration predominantly being between 11-15 minutes (71%) and 16-20 minutes (27%). Most treatment delivered was passive in nature (71%) although combination active and passive care was provided (27%). Treatment typically involved joint (81%) and soft tissue based therapies (81%) and was delivered in a full body manner. Conclusions This study documented the injury profile of ice hockey at an international level of competition. It documented the

  14. Strategic decisions of ice hockey coaches as a function of game location.

    PubMed

    Dennis, P W; Carron, A V

    1999-04-01

    Two studies were performed to determine the influence of game location on the strategic decisions of ice hockey coaches. In study 1, coaches from the National (n = 23) and Ontario Hockey Leagues (n = 17) indicated the degree to which they had their teams forecheck assertively at home versus away. In study 2, video analysis of 62 National Hockey League games was used to verify the extent to which teams in this league use an assertive forechecking strategy at home versus away. In study 1, coaches reported that they implemented a more assertive forechecking style at home versus away (P < 0.001). The results of the video analysis in study 2 were consistent with the coaches' reports: teams used a more assertive forechecking style at home versus away (P < 0.03). The results are discussed in terms of their implications for the home advantage in the National Hockey League. PMID:10373036

  15. Ice Hockey Summit II: zero tolerance for head hits and fighting.

    PubMed

    Smith, Aynsley M; Stuart, Michael J; Dodick, David W; Roberts, William O; Alford, Patrick W; Ashare, Alan B; Aubrey, Mark; Benson, Brian W; Burke, Chip J; Dick, Randall; Eickhoff, Chad; Emery, Carolyn A; Flashman, Laura A; Gaz, Daniel V; Giza, Chris C; Greenwald, Richard M; Herring, Stanley A; Hoshizaki, T Blaine; Hudziak, James J; Huston, John; Krause, David; LaVoi, Nicole; Leaf, Matt; Leddy, John J; MacPherson, Alison; McKee, Ann C; Mihalik, Jason P; Moessner, Anne M; Montelpare, William J; Putukian, Margot; Schneider, Kathryn J; Szalkowski, Ron; Tabrum, Mark; Whitehead, James R; Wiese-Bjornstal, Diane M

    2015-01-01

    This study aimed to present currently known basic science and on-ice influences of sport-related concussion (SRC) in hockey, building upon the Ice Hockey Summit I action plan (2011) to reduce SRC. The prior summit proceedings included an action plan intended to reduce SRC. As such, the proceedings from Summit I served as a point of departure for the science and discussion held during Summit II (Mayo Clinic, Rochester, MN, October 2013). Summit II focused on (1) Basic Science of Concussions in Ice Hockey: Taking Science Forward, (2) Acute and Chronic Concussion Care: Making a Difference, (3) Preventing Concussions via Behavior, Rules, Education, and Measuring Effectiveness, (4) Updates in Equipment: Their Relationship to Industry Standards, and (5) Policies and Plans at State, National, and Federal Levels To Reduce SRC. Action strategies derived from the presentations and discussion described in these sectors were voted on subsequently for purposes of prioritization. The following proceedings include the knowledge and research shared by invited faculty, many of whom are health care providers and clinical investigators. The Summit II evidence-based action plan emphasizes the rapidly evolving scientific content of hockey SRC. It includes the most highly prioritized strategies voted on for implementation to decrease concussion. The highest-priority action items identified from the Summit include the following: (1) eliminate head hits from all levels of ice hockey, (2) change body checking policies, and (3) eliminate fighting in all amateur and professional hockey. PMID:25757010

  16. Development of hydroacoustical techniques for the monitoring and classification of benthic habitats in Puck Bay: Modeling of acoustic waves scattering by seagrass

    NASA Astrophysics Data System (ADS)

    Raczkowska, A.; Gorska, N.

    2012-12-01

    Puck Bay is an area of high species biodiversity belonging to the Coastal Landscape Park of Baltic Sea Protected Areas (BSPA) and is also included in the list of the World Wide Fund for Nature (WWF) and covered by the protection program "Natura 2000". The underwater meadows of the Puck Bay are important for Europe's natural habitats due to their role in enhancing the productivity of marine ecosystems and providing shelter and optimal feeding conditions for many marine organisms. One of the dominant species comprising the underwater meadows of the Southern Baltic Sea is the seagrass Zostera marina. The spatial extent of underwater seagrass meadows is altered by pollution and eutrophication; therefore, to properly manage the area one must monitor its ecological state. Remote acoustic methods are useful tools for the monitoring of benthic habitats in many marine areas because they are non-invasive and allow researchers to obtain data from a large area in a short period of time. Currently there is a need to apply these methods in the Baltic Sea. Here we present an analysis of the mechanism of scattering of acoustic waves on seagrass in the Southern Baltic Sea based on the numerical modeling of acoustic wave scattering by the biological tissues of plants. The study was conducted by adapting a model developed on the basis of DWBA (Distorted Wave Born Approximation) developed by Stanton and Chu (2005) for fluid-like objects, including the characteristics of the Southern Baltic seagrass. Input data for the model, including the morphometry of seagrass leaves, their angle of inclination and the density plant cover, was obtained through the analysis of biological materials collected in the Puck Bay in the framework of a research project financed by the Polish Government (Development of hydroacoustic methods for studies of underwater meadows of Puck Bay, 6P04E 051 20). On the basis of the developed model, we have analyzed the dependence of the target strength of a single

  17. A comparison of the epidemiology of ice hockey injuries between male and female youth in Canada

    PubMed Central

    Forward, Karen E; Seabrook, Jamie A; Lynch, Tim; Lim, Rodrick; Poonai, Naveen; Sangha, Gurinder S

    2014-01-01

    BACKGROUND: Hockey is played by youth across Canada, and its popularity has increased dramatically among females in the past decade. Despite this, there has been little epidemiological research comparing the injury patterns of young female and male hockey players. OBJECTIVE: To describe and compare injuries sustained by female and male youth hockey players using the Canadian Hospitals Injury Reporting and Prevention Program database. METHODS: In the present cross-sectional, retrospective comparison study, the Canadian Hospitals Injury Reporting and Prevention Program database was used to identify all hockey-related injuries sustained by children seven to 17.5 years of age over a 15-year period (January 1995 to December 2009). Exclusion criteria included paid professional players and children with injuries sustained while playing road hockey. RESULTS: Inclusion criteria were met by 33,233 children (2637 [7.9%] females and 30,596 [92.1%] males). Compared with males, females reported proportionately more soft tissue injuries (39.8% versus 32.6%; P<0.01) and sprains/strains (21.1% versus 17.6%; P<0.01). Males experienced more fractures (27.1% versus 18.2%; P<0.01) and were most often injured through body checking (42.8% versus 25.7%; P<0.01). Females showed a trend toward increased concussion with age, and were most often injured through collisions (28.6% versus 24.6%; P<0.01). CONCLUSION: Compared with males, female hockey players sustained proportionately more soft tissue injures and sprains/strains, and showed a trend toward concussions in late adolecence. Males experienced more fractures, shoulder injuries and injuries due to body checking. Further research is required to identify risk factors for injury in female youth hockey players and to target injury prevention. PMID:25382998

  18. Game Intensity Analysis of Elite Adolescent Ice Hockey Players

    PubMed Central

    Stanula, Arkadiusz; Roczniok, Robert

    2014-01-01

    The purpose of this study was to determine ice-hockey players’ playing intensity based on their heart rates (HRs) recorded during a game and on the outcomes of an incremental maximum oxygen uptake test. Twenty ice-hockey players, members of the Polish junior national team (U18), performed an incremental test to assess their maximal oxygen uptake (V̇O2max) in the two week’s period preceding 5 games they played at the World Championships. Players’ HRs at the first and second ventilatory thresholds obtained during the test were utilized to determine intensity zones (low, moderate, and high) that were subsequently used to classify HR values recorded during each of the games. For individual intensity zones, the following HRs expressed as mean values and as percentages of the maximal heart rate (HRmax) were obtained: forwards 148–158 b·min−1 (79.5–84.8% HRmax), 159–178 b·min−1 (85.4–95.6% HRmax), 179–186 b·min−1 (96.1–100.0% HRmax); defensemen 149–153 b·min−1 (80.0–82.1% HRmax), 154–175 b·min−1 (82.6–94.0% HRmax), 176–186 b·min−1 (94.5–100.0% HRmax). The amount of time the forwards and defensemen spent in the three intensity zones expressed as percentages of the total time of the game were: 54.91 vs. 55.62% (low), 26.40 vs. 22.38% (moderate) and 18.68 vs. 22.00% (high). The forwards spent more time in the low intensity zone than the defensemen, however, the difference was not statistically significant. The results of the study indicate that using aerobic and anaerobic metabolism variables to determine intensity zones can significantly improve the reliability of evaluation of the physiological demands of the game, and can be a useful tool for coaches in managing the training process. PMID:25713682

  19. Physiological, physical and on-ice performance criteria for selection of elite ice hockey teams

    PubMed Central

    Roczniok, R; Stanula, A; Mostowik, A; Kowalczyk, M; Fidos-Czuba, O; Zając, A

    2015-01-01

    The purpose of this study was to examine physiological and physical determinants of ice-hockey performance in order to assess their impact on the result during a selection for ice hockey. A total of 42 ice hockey players took part in the selection camp. At the end of the camp 20 best players were selected by team of expert coaches to the ice hockey team and created group G1, while the second group (G2) consisted of not selected players (non-successful group Evaluation of goodness of fit of the model to the data was based on the Hosmer Lemeshow test. Ice hockey players selected to the team were taller 181.95±4.02 cm, had lower% body fat 13.17±3.17%, a shorter time to peak power 2.47±0.35 s, higher relative peak power 21.34±2.41 W·kg−1 and higher relative total work 305.18±28.41 J·kg−1. The results of the aerobic capacity test showed significant differences only in case of two variables. Ice hockey players in the G1 had higher VO2max 4.07±0.31 l·min−1 values than players in the G2 as well as ice hockey players in G1 showed a higher level of relative VO2max 51.75±2.99 ml·min−1·kg−1 than athletes in G2. Ice hockey players selected to the team (G1) performed better in the 30 m Forwards Sprint 4.28±0.31 s; 6x9 Turns 12.19±0.75 s; 6x9 stops 12.79±0.49 s and Endurance test (6x30 m stops) 32.01±0.80 s than players in G2. The logistic regression model showed that the best predictors of success in the recruitment process of top level ice hockey players were time to peak power, relative peak power, VO2max and 30 m sprint forwards on ice. On the basis of the constructed predictive logistic regression model it will be possible to determine the probability of success of the athletes during following the selection processes to the team. PMID:26985133

  20. Integration of the functional movement screen into the National Hockey League Combine.

    PubMed

    Rowan, Chip P; Kuropkat, Christiane; Gumieniak, Robert J; Gledhill, Norman; Jamnik, Veronica K

    2015-05-01

    The sport of ice hockey requires coordination of complex skills involving musculoskeletal and physiological abilities while simultaneously exposing players to a high risk for injury. The Functional Movement Screen (FMS) was developed to assess fundamental movement patterns that underlie both sport performance and injury risk. The top 111 elite junior hockey players from around the world took part in the 2013 National Hockey League Entry Draft Combine (NHL Combine). The FMS was integrated into the comprehensive medical and physiological fitness evaluations at the request of strength and conditioning coaches with affiliations to NHL teams. The inclusion of the FMS aimed to help develop strategies that could maximize its utility among elite hockey players and to encourage or inform further research in this field. This study evaluated the outcomes of integrating the FMS into the NHL Combine and identified any links to other medical plus physical and physiological fitness assessment outcomes. These potential associations may provide valuable information to identify elements of future training programs that are individualized to athletes' specific needs. The results of the FMS (total score and number of asymmetries identified) were significantly correlated to various body composition measures, aerobic and anaerobic fitness, leg power, timing of recent workouts, and the presence of lingering injury at the time of the NHL Combine. Although statistically significant correlations were observed, the implications of the FMS assessment outcomes remain difficult to quantify until ongoing assessment of FMS patterns, tracking of injuries, and hockey performance are available. PMID:25719918

  1. Conservative management of an elite ice hockey goaltender with femoroacetabular impingement (FAI): a case report

    PubMed Central

    MacIntyre, Kyle; Gomes, Brendan; MacKenzie, Steven; D’Angelo, Kevin

    2015-01-01

    Objective: To detail the presentation of an elite male ice hockey goaltender with cam-type femoroacetabular impingement (FAI) and acetabular labral tears. This case will outline the prevalence, clinical presentation, imaging criteria, pathomechanics, and management of FAI, with specific emphasis on the ice hockey goaltender. Clinical Features: A 22-year old retired ice hockey goaltender presented to a chiropractor after being diagnosed by an orthopaedic surgeon with MRI confirmed left longitudinal and chondral flap acetabular labral tears and cam-type femoroacetabular impingement (FAI). As the patient was not a candidate for surgical intervention, a multimodal conservative treatment approach including manual therapy, electroacupuncture and rehabilitation exercises were implemented. Summary: FAI is prevalent in ice hockey players, particularly with goaltenders. Both skating and position-dependent hip joint mechanics involved in ice hockey may exacerbate or contribute to acquired and congenital forms of symptomatic FAI. As such, practitioners managing this population must address sport-specific demands in manual therapy, rehabilitation and physical training, to improve functional outcomes and prevent future injury. PMID:26816416

  2. Psychosocial Outcomes of Sport Concussions in Youth Hockey Players.

    PubMed

    Mrazik, Martin; Brooks, Brian L; Jubinville, Andrea; Meeuwisse, Willem H; Emery, Carolyn A

    2016-06-01

    The objective is to evaluate the psychological outcomes arising from sport concussions. Participants included AA and AAA level Bantam and Midget hockey players (n = 672) between 12 and 17 years of age (mean = 15.0 years; SD = 1.2) enrolled in a large cohort study. All participants completed baseline tests including the Behavior Assessment System for Children, 2nd Edition (BASC2) and a pre-season medical questionnaire (PSQ) completed by parents that included a retrospective report of prior concussions and injuries. Players were assigned to 4 groups: no injury (NONE), concussion (CO) and musculoskeletal (MSK) injuries or both (COMB). Participants in the CO and COMB groups demonstrated significantly higher rates of psychological difficulties compared with other groups [F(63, 1800) = 1.43, p = .016, partial η(2) = 0.05) and on select clinical scales measuring atypicality, locus of control, anxiety, depression, sense of inadequacy, somatization, and attention. In addition, results from the composite clinical scales reached statistical significance for internalizing problems and emotional symptom index. Effect sizes were minimal with the exception of comparisons between the NONE and COMB groups where effect sizes were medium to large. Proportions above clinical cut-off scores set by the BASC2 were higher for the COMB group compared with CO, MSK, or NONE groups. Results suggest smaller percentage of youth may be more prone to psychological sequelae following concussion. PMID:27084731

  3. Neuropsychological factors related to college ice hockey concussions.

    PubMed

    Pedersen, Heather A; Ferraro, F Richard; Himle, Michael; Schultz, Caitlin; Poolman, Mark

    2014-05-01

    We analyzed data from 74 male collegiate hockey players. Each athlete's season began with a baseline administration of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) neuropsychology test battery. Fourteen athletes sustained a sport-related head injury and were readministered the test to assess the impact of the injury. A significant decrease in performance (compared to baseline) on immediate and delayed word recall and designs followed the first concussion. Following a second sport-related concussion, the 4 affected athletes showed significant decrease in visual motor speed. Performance improved on 2 response speed measures (Ps < .01). More errors occurred during a visual processing/discrimination task and immediate recall of designs declined (Ps < .05). We discuss the results in light of recent work related to the impact of early-life concussions and head injury on late-life consequences, such as chronic traumatic encephalopathy, and more immediate issues such as return-to-play decisions for athletes. PMID:24370620

  4. Gender Differences in Head Impacts Sustained by Collegiate Ice Hockey Players

    PubMed Central

    Brainard, Lindley L.; Beckwith, Jonathan G.; Chu, Jeffrey J.; Crisco, Joseph J.; McAllister, Thomas W.; Duhaime, Ann-Christine; Maerlender, Arthur C.; Greenwald, Richard M.

    2013-01-01

    Purpose This study aims to quantify the frequency, magnitude, and location of head impacts sustained by male and female collegiate ice hockey players over two seasons of play. Methods Over two seasons, 88 collegiate athletes (51 female, 37 male) on two female and male NCAA varsity ice hockey teams wore instrumented helmets. Each helmet was equipped with 6 single-axis accelerometers and a miniature data acquisition system to capture and record head impacts sustained during play. Data collected from the helmets were post-processed to compute linear and rotational acceleration of the head as well as impact location. The head impact exposure data (frequency, location, and magnitude) were then compared across gender. Results Female hockey players experienced a significantly lower (p < 0.001) number of impacts per athlete exposure than males (female: 1.7 ± 0.7; male: 2.9 ± 1.2). The frequency of impacts by location was the same between gender (p > 0.278) for all locations except the right side of the head, where males received fewer impacts than females (p = 0.031). Female hockey players were 1.1 times more likely than males to sustain an impact less than 50 g while males were 1.3 times more likely to sustain an impact greater than 100 g. Similarly, males were 1.9 times more likely to sustain an impact with peak rotational acceleration greater than 5,000 rad/s2 and 3.5 times more likely to sustain an impact greater than 10,000 rad/s2. Conclusions Although the incidence of concussion has typically been higher for female hockey players than male hockey players, female players sustain fewer impacts and impacts resulting in lower head acceleration than males. Further study is required to better understand the intrinsic and extrinsic risk factors that lead to higher rates of concussion for females that have been previously reported. PMID:21716150

  5. Planets and Pucks.

    ERIC Educational Resources Information Center

    Brueningsen, Christopher; Krawiec, Wesley

    1993-01-01

    Presents a simple activity designed to allow students to experimentally verify Kepler's second law, sometimes called the law of equal areas. It states that areas swept out by a planet as it orbits the Sun are equal for equal time intervals. (PR)

  6. Lesbian erotics at women's hockey: fans, flashing, and the Booby Orrs.

    PubMed

    Davidson, Judy

    2009-01-01

    This article analyzes a public breast flashing event that occurred during the women's ice hockey tournament at the OutGames/Western Cup Lesbigay athletic event in 2007. Employing a postfoundational perspective, I first contextualize the ice hockey subculture of the team called the Booby Orrs, outlining some of our history, norms, and context. I then tell the particular story that leads to our fans flashing their breasts as we finally scored some goals. I end with my analysis of this event: how a public nude display of sexualized women's breasts in a lesbian-coded public space prompted a resistant sporting moment, at least contingently. PMID:19598052

  7. Layer thinning transition in an achiral four-ring hockey stick shaped liquid crystal

    NASA Astrophysics Data System (ADS)

    Paul, Manoj Kr.; Nath, Rahul K.; Moths, Brian; Pan, LiDong; Wang, Shun; Deb, Rajdeep; Shen, Yongqiang; Rao, Nandiraju V. S.; Huang, C. C.

    2012-12-01

    Depolarized reflected light microscopy and high resolution optical reflectivity measurements have been conducted on free-standing films of an achiral four-ring hockey stick shaped liquid crystal exhibiting SmA-B2-SmX* transition sequence. A layer thinning transition above the bulk isotropic-SmA phase transition has been observed. This behaviour was highly irreproducible, indicating an irregular layer thinning transition. From optical reflectivity data, both thickness of the free-standing films and the smectic interlayer spacing were determined. This is the first report of the layer thinning transition in a hockey stick shaped liquid crystal.

  8. [The efficacy of ultrasound-guided infraorbital nerve block with hockey stick typed probe].

    PubMed

    Iwase, Naoto; Fukui, Hidekimi; Yuunaiyama, Youko; Kaneko, Kouki; Ohseto, Kiyoshige; Uchino, Hiroyuki

    2013-10-01

    We report a case of ultrasound-guided infraorbital nerve block with a hockey stick typed probe in plane approach. Individual difference of infraorbital anatomy makes it difficult to puncture the infraorbital for a man, and the risks include bleeding, double vision and paranasal sinus puncture. The advantage of ultrasound-guided nerve block has been reported. Compared with conventional land mark method approach, ultrasound technique is thought to be easy to perform, more quickly and safely without any complications. From our results, we have demonstrated that ultrasound-guided infraorbital nerve block assisted by hockey stick typed probe could become one of the safe methods for this purpose. PMID:24228458

  9. The past, present, and future of hockey-stick-shaped liquid crystals

    NASA Astrophysics Data System (ADS)

    Choi, E.-Joon

    2014-02-01

    Recently, the liquid crystalline materials with a bent-core mesogen have attracted attentions because their interesting properties such as polarity and biaxiality of the mesophase. There are several types of bent-core mesogenic structures have been reported, for instance, banana-shaped, V-shaped molecules, boomerang-shaped, hockey stick-shaped, and Yshaped molecules. In this study, the liquid crystals and the reactive mesogens with the hockey-stick shaped mesogens will be described concerning with the structure-property relationship.

  10. A new pelvic tilt detection device: roentgenographic validation and application to assessment of hip motion in professional ice hockey players.

    PubMed

    Tyler, T; Zook, L; Brittis, D; Gleim, G

    1996-11-01

    Professional ice hockey players often sustain hip and low back strains. We hypothesized that playing the sport of ice hockey may result in the shortening of the iliopsoas muscles, increasing the likelihood of lumbosacral strains and hip injuries. The purpose of this study was to identify whether ice hockey players demonstrate a decrease in hip extension range of motion when compared with age-matched controls. Objective data were obtained using the Thomas test with an electrical circuit device to determine pelvic tilt motion. The device was validated by obtaining X-rays in six subjects during the Thomas test. The study then examined 25 professional hockey players and 25 age-matched controls. A two-way analysis of variance was applied for statistical analysis to examine the effect of sport and side. The results demonstrated that ice hockey players have a reduced mean hip extension range of motion (p < .0001) by comparison with age-match controls. There was no difference between right and left sides, nor was there any interaction of the sport with the side of the body. Therefore, hockey players demonstrated a decreased extensibility of the iliopsoas muscles. Future research may be directed toward establishing a link between prophylactic stretching and injury rate in professional ice hockey players. PMID:8902682

  11. Experiential Learning in the Introductory Class: The Role of Minor League Hockey in Teaching Social Psychology

    ERIC Educational Resources Information Center

    Forrest, Krista D.

    2005-01-01

    To convince my students they are surrounded by social psychology, we attended a minor league hockey game. During the next class period I asked students to write a brief paragraph about their experiences. From those paragraphs I chose four reoccurring themes to analyze from a social psychological perspective. My introductory classes and I benefited…

  12. Sports Institute for Research/Change Agent Research (SIR/CAR) Windsor Minor Hockey.

    ERIC Educational Resources Information Center

    Moriarty, Dick; Duthie, James

    This organizational analysis of Windsor minor hockey was conducted as a pilot study into the policy decision making process in a sports organization. The study was divided into three phases. In the first phase the organization was audited and provided with information about various feedback channels. In phase two observations, available…

  13. A test of motor skill-specific action embodiment in ice-hockey players.

    PubMed

    Ong, Nicole T; Lohse, Keith R; Chua, Romeo; Sinnett, Scott; Hodges, Nicola J

    2014-07-01

    To further our understanding of the role of the motor system in comprehending action-related sentences, we compared action experts (athletes) to visual experts (fans) and novices when responding with an action-specific effector (either hand or foot). These conditions allowed inferences about the degree and specificity of embodiment in language comprehension. Ice hockey players, fans and novices made speeded judgments regarding the congruence between an auditorily presented sentence and a subsequently presented picture. Picture stimuli consisted of either hockey or everyday items. Half of these pictures 'matched' the action implied in the preceding sentence. Further, the action in these images involved either primarily the hand or the foot. For everyday items, action-matched items were responded to faster than action-mismatched items. However, only the players and fans showed the action-match effect for hockey items. There were no consistent effector-stimuli compatibility effects, nor skill-based interactions with compatibility, suggesting that the action-match effect was not based on motor ability per se, but rather a construction of the action based on knowledge or visual experience with the hockey related sentences. PMID:24818535

  14. Describing Strategies Used by Elite, Intermediate, and Novice Ice Hockey Referees

    ERIC Educational Resources Information Center

    Hancock, David J.; Ste-Marie, Diane M.

    2014-01-01

    Much is known about sport officials' decisions (e.g., anticipation, visual search, and prior experience). Comprehension of the entire decision process, however, requires an ecologically valid examination. To address this, we implemented a 2-part study using an expertise paradigm with ice hockey referees. Purpose: Study 1 explored the…

  15. Previous-day hypohydration impairs skill performance in elite female field hockey players.

    PubMed

    MacLeod, H; Sunderland, C

    2012-06-01

    The purpose of this study was to determine the effects of 2% hypohydration on skill performance in elite female field hockey players following intermittent exercise in the heat. Eight elite female field hockey players performed 50 min of a field hockey-specific intermittent treadmill running protocol (FHITP) in hot environmental conditions (33 °C, 60% relative humidity) in different hydration states: euhydrated (EUH) and hypohydrated by 2% body mass (HYPO). Hydration status was manipulated via a period (121±10 min) of passive hyperthermia (40 °C, 75% relative humidity) and controlled fluid intake 1 day preceding testing. Ad libitum fluid intake was permitted throughout both trials. Field hockey skill tests were performed pre- and post-FHITP. Skill performance time increased (P=0.029) in the HYPO trial compared with the EUH trial, which may be attributed to an increase in penalty time (P=0.024). Decision-making time increased (P=0.008) in the HYPO trial and was significantly impaired compared with EUH (P=0.016) pre-FHITP. Ad libitum drinking appeared to be sufficient to maintain decision-making performance as no interaction effects were evident post-FHITP. Players who commence match-play in a state of hypohydration may be susceptible to decrements in skill and decision-making performance. PMID:20973829

  16. Predictors of Speed Using Off-Ice Measures of College Hockey Players.

    PubMed

    Runner, Aaron R; Lehnhard, Robert A; Butterfield, Stephen A; Tu, Shihfen; OʼNeill, Terrence

    2016-06-01

    Runner, AR, Lehnhard, RA, Butterfield, SA, Tu, S, and O'Neill, T. Predictors of speed using off-ice measures of college hockey players. J Strength Cond Res 30(6): 1626-1632, 2016-The purpose of this study was to examine the relationship between commonly employed dry-land performance tests and skating speed in male collegiate ice hockey players. Forty male National Collegiate Athletic Association Division I hockey players were tested on the following performance variables: vertical jump (VJ), standing broad jump, 40-yard dash, and maximal back squat (SQT). The subjects also performed 3 skating tests: the 90-ft forward acceleration test, the 90-ft backward acceleration test, and the 50-ft flying top speed test (F50). Pearson correlation coefficients were applied to compare the strength of association between each selected off-ice measure and each on-ice measure. Three multiple regression equations were then used to compare the weighted strengths of association between predictor and criterion variables. Only VJ showed significance in relation to skating speed (p = 0.011). These results suggest that meaningful performance testing in ice hockey players should occur mainly on the ice. PMID:25719922

  17. Comparison of Dynamic Balance in Collegiate Field Hockey and Football Players Using Star Excursion Balance Test

    PubMed Central

    Bhat, Rashi; Moiz, Jamal Ali

    2013-01-01

    Purpose The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. Methods A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45° increments. The subjects were instructed to maintain a stable single leg stance with the test leg with shoes off and to reach for maximal distance with the other leg in each of the 8 directions. A pencil was used to point and read the distance to which each subject's foot reached. The normalized leg reach distances in each direction were summed for both limbs and the total sum of the mean of summed normalized distances of both limbs were calculated. Results There was no significant difference in all the directions of star excursion balance test scores in both the groups. Additionally, composite reach distances of both groups also found non-significant (P=0.5). However, the posterior (P=0.05) and lateral (P=0.03) normalized reach distances were significantly more in field hockey players. Conclusion Field hockey players and football players did not differ in terms of dynamic balance. PMID:24427482

  18. Selected Field Hockey and Lacrosse Articles. Sports Articles Reprint Series. Third Edition.

    ERIC Educational Resources Information Center

    Stewart, Harriet, Ed.

    This collection of articles from 1964-1970 "Field Hockey-Lacrosse Guides" by the Division for Girls and Women's Sports is the latest in the American Association for Health, Physical Education, and Recreation's "Sports Articles Reprint Series." A special project of the Publications Committee for Girl's and Women's Sports, it is the third edition of…

  19. Ice Hockey Players Using a Weighted Implement when Training on the Ice: A Randomized Control Trial

    ERIC Educational Resources Information Center

    Stark, Timothy W.; Tvoric, Bojan; Walker, Bruce; Noonan, Dom; Sibla, Janeene

    2009-01-01

    The purpose of this study was to investigate the potential for improving hockey players' performance using a weighted implement on the ice. Forty-eight players were tested using a grip strength dynamometer. They also were assessed on their abilities to stick-handle. The participants were randomly placed into a control or research group. The…

  20. Receiving Video-Based Feedback in Elite Ice-Hockey: A Player's Perspective

    ERIC Educational Resources Information Center

    Nelson, Lee J.; Potrac, Paul; Groom, Ryan

    2014-01-01

    The aim of this paper was to provide some rich insights into how an elite ice-hockey player responded to his coaches' pedagogical delivery of video-based feedback sessions. Data for this study were gathered through a series of in-depth, semi-structured interviews and a reflective log relating to those interviews. The interviews were…

  1. Checking in: An Analysis of the (Lack of) Body Checking in Women's Ice Hockey

    ERIC Educational Resources Information Center

    Weaving, Charlene; Roberts, Samuel

    2012-01-01

    Despite the growing popularity of women's ice hockey in North America, players continue to face limitations because of the prohibition of body checking. In this paper, we argue from a liberal feminist philosophical perspective that this prohibition reinforces existing traditional stereotypes of female athletes. Because the women's game does not…

  2. The Control of Externalities in Sports Leagues: An Analysis of Restrictions in the National Hockey League

    ERIC Educational Resources Information Center

    Carlton, Dennis W.; Frankel, Alan S.; Landes, Elisabeth M.

    2004-01-01

    This paper provides one of the few successful demonstrations of the efficiency of certain types of restrictions in the context of a joint venture. The joint venture we examine is the National Hockey League (NHL) in the 1980s, which was then composed of 21 separately owned teams. (It now has 30 teams.) The restriction we analyze is the NHL rule on…

  3. Trajectories of Affective States in Adolescent Hockey Players: Turning Point and Motivational Antecedents

    ERIC Educational Resources Information Center

    Gaudreau, Patrick; Amiot, Catherine E.; Vallerand, Robert J.

    2009-01-01

    This study examined longitudinal trajectories of positive and negative affective states with a sample of 265 adolescent elite hockey players followed across 3 measurement points during the 1st 11 weeks of a season. Latent class growth modeling, incorporating a time-varying covariate and a series of predictors assessed at the onset of the season,…

  4. Explosive Model Tarantula V1/JWL++ Calibration of LX-17: #2

    SciTech Connect

    Souers, P C; Vitello, P

    2009-05-01

    Tarantula V1 is a kinetic package for reactive flow codes that seeks to describe initiation, failure, dead zones and detonation simultaneously. The most important parameter is P1, the pressure between the initiation and failure regions. Both dead zone formation and failure can be largely controlled with this knob. However, V1 does failure with low settings and dead zones with higher settings, so that it cannot fulfill its purpose in the current format. To this end, V2 is under test. The derivation of the initiation threshold P0 is discussed. The derivation of the initiation pressure-tau curve as an output of Tarantula shows that the initiation package is sound. A desensitization package is also considered.

  5. Aggression, Violence and Injury in Minor League Ice Hockey: Avenues for Prevention of Injury

    PubMed Central

    Cusimano, Michael D.; Ilie, Gabriela; Mullen, Sarah J.; Pauley, Christopher R.; Stulberg, Jennifer R.; Topolovec-Vranic, Jane; Zhang, Stanley

    2016-01-01

    Background In North America, more than 800,000 youth are registered in organized ice hockey leagues. Despite the many benefits of involvement, young players are at significant risk for injury. Body-checking and aggressive play are associated with high frequency of game-related injury including concussion. We conducted a qualitative study to understand why youth ice hockey players engage in aggressive, injury-prone behaviours on the ice. Methods Semi-structured interviews were conducted with 61 minor ice hockey participants, including male and female players, parents, coaches, trainers, managers and a game official. Players were aged 13–15 playing on competitive body checking teams or on non-body checking teams. Interviews were manually transcribed, coded and analyzed for themes relating to aggressive play in minor ice hockey. Results Parents, coaches, teammates and the media exert a large influence on player behavior. Aggressive behavior is often reinforced by the player’s social environment and justified by players to demonstrate loyalty to teammates and especially injured teammates by seeking revenge particularly in competitive, body-checking leagues. Among female and male players in non-body checking organizations, aggressive play is not reinforced by the social environment. These findings are discussed within the framework of social identity theory and social learning theory, in order to understand players’ need to seek revenge and how the social environment reinforces aggressive behaviors. Conclusion This study provides a better understanding of the players’ motivations and environmental influences around aggressive and violent play which may be conducive to injury. The findings can be used to help design interventions aimed at reducing aggression and related injuries sustained during ice hockey and sports with similar cultures and rules. PMID:27258426

  6. Knee joint position sense of roller hockey players: a comparative study.

    PubMed

    Venâncio, João; Lopes, Diogo; Lourenço, Joaquim; Ribeiro, Fernando

    2016-06-01

    This study aimed to compare knee joint position sense of roller hockey players with an age-matched group of non-athletes. Forty-three male participants voluntarily participated in this cross-sectional study: 21 roller hockey players (mean age: 23.2 ± 4.2 years old, mean weight: 81.8 ± 9.8 kg, mean height: 180.5 ± 4.1 cm) and 22 age-matched non-athletes (mean age: 23.7 ± 3.9 years old, mean weight: 85.0 ± 6.2 kg, mean height: 181.5 ± 5.0 cm). Knee joint position sense of the dominant limb was evaluated using a technique of open-kinetic chain and active knee positioning. Joint position sense was reported using absolute, relative and variable angular errors. The main results indicated that the group of roller hockey players showed significantly lower absolute (2.4 ± 1.2º vs. 6.5 ± 3.2º, p ≤ 0.001) and relative (1.7 ± 2.1º vs. 5.8 ± 4.4º, p ≤ 0.001) angular errors in comparison with the non-athletes group. In conclusion, the results from this present study suggest that proprioceptive acuity, assessed by measuring joint position sense, is increased in roller hockey players. The enhanced proprioception of the roller hockey players could contribute to injury prevention and improved performance during sporting activities. PMID:27111126

  7. Physiological correlates of skating performance in women's and men's ice hockey.

    PubMed

    Gilenstam, Kajsa M; Thorsen, Kim; Henriksson-Larsén, Karin B

    2011-08-01

    The purpose of the current investigation was to identify relationships between physiological off-ice tests and on-ice performance in female and male ice hockey players on a comparable competitive level. Eleven women, 24 ± 3.0 years, and 10 male ice hockey players, 23 ± 2.4 years, were tested for background variables: height, body weight (BW), ice hockey history, and lean body mass (LBM) and peak torque (PT) of the thigh muscles, VO2peak and aerobic performance (Onset of Blood Lactate Accumulation [OBLA], respiratory exchange ratio [RER1]) during an incremental bicycle ergometer test. Four different on-ice tests were used to measure ice skating performance. For women, skating time was positively correlated (p < 0.05) to BW and negatively correlated to LBM%, PT/BW, OBLA, RER 1, and VO2peak (ml O2·kg(-1) BW(-1)·min(-1)) in the Speed test. Acceleration test was positively correlated to BW and negatively correlated to OBLA and RER 1. For men, correlation analysis revealed only 1 significant correlation where skating time was positively correlated to VO2peak (L O2·min(-1)) in the Acceleration test. The male group had significantly higher physiological test values in all variables (absolute and relative to BW) but not in relation to LBM. Selected off-ice tests predict skating performance for women but not for men. The group of women was significantly smaller and had a lower physiological performance than the group of men and were slower in the on-ice performance tests. However, gender differences in off-ice variables were reduced or disappeared when values were related to LBM, indicating a similar capacity of producing strength and aerobic power in female and male hockey players. Skating performance in female hockey players may be improved by increasing thigh muscle strength, oxygen uptake, and relative muscle mass. PMID:21785292

  8. The hockey-stick method to estimate evening dim light melatonin onset (DLMO) in humans.

    PubMed

    Danilenko, Konstantin V; Verevkin, Evgeniy G; Antyufeev, Viktor S; Wirz-Justice, Anna; Cajochen, Christian

    2014-04-01

    The onset of melatonin secretion in the evening is the most reliable and most widely used index of circadian timing in humans. Saliva (or plasma) is usually sampled every 0.5-1 hours under dim-light conditions in the evening 5-6 hours before usual bedtime to assess the dim-light melatonin onset (DLMO). For many years, attempts have been made to find a reliable objective determination of melatonin onset time either by fixed or dynamic threshold approaches. The here-developed hockey-stick algorithm, used as an interactive computer-based approach, fits the evening melatonin profile by a piecewise linear-parabolic function represented as a straight line switching to the branch of a parabola. The switch point is considered to reliably estimate melatonin rise time. We applied the hockey-stick method to 109 half-hourly melatonin profiles to assess the DLMOs and compared these estimates to visual ratings from three experts in the field. The DLMOs of 103 profiles were considered to be clearly quantifiable. The hockey-stick DLMO estimates were on average 4 minutes earlier than the experts' estimates, with a range of -27 to +13 minutes; in 47% of the cases the difference fell within ±5 minutes, in 98% within -20 to +13 minutes. The raters' and hockey-stick estimates showed poor accordance with DLMOs defined by threshold methods. Thus, the hockey-stick algorithm is a reliable objective method to estimate melatonin rise time, which does not depend on a threshold value and is free from errors arising from differences in subjective circadian phase estimates. The method is available as a computerized program that can be easily used in research settings and clinical practice either for salivary or plasma melatonin values. PMID:24224578

  9. Caffeinated Energy Drinks Improve High-Speed Running in Elite Field Hockey Players.

    PubMed

    Del Coso, Juan; Portillo, Javier; Salinero, Juan José; Lara, Beatriz; Abian-Vicen, Javier; Areces, Francisco

    2016-02-01

    The aim of this investigation was to determine the efficacy of a caffeine-containing energy drink to improve physical performance of elite field hockey players during a game. On 2 days separated by a week, 13 elite field hockey players (age and body mass = 23.2 ± 3.9 years and 76.1 ± 6.1 kg) ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo drink). After 60 min for caffeine absorption, participants played a simulated field hockey game (2 × 25 min). Individual running pace and instantaneous speed during the game were assessed using GPS devices. The total number of accelerations and decelerations was determined by accelerometry. Compared with the placebo drink, the caffeinated energy drink did not modify the total distance covered during the game (6,035 ± 451 m and 6,055 ± 499 m, respectively; p = .87), average heart rate (155 ± 13 beats per min and 158 ± 18 beats per min, respectively; p = .46), or the number of accelerations and decelerations (697 ± 285 and 618 ± 221, respectively; p = .15). However, the caffeinated energy drink reduced the distance covered at moderate-intensity running (793 ± 135 and 712 ± 116, respectively; p = .03) and increased the distance covered at high-intensity running (303 ± 67 m and 358 ± 117 m; p = .05) and sprinting (85 ± 41 m and 117 ± 55 m, respectively; p = .02). Elite field hockey players can benefit from ingesting caffeinated energy drinks because they increase the running distance covered at high-intensity running and sprinting. Increased running distance at high speed might represent a meaningful advantage for field hockey performance. PMID:26251550

  10. The Protective Effect of Kevlar ® Socks Against Hockey Skate Blade Injuries: A Biomechanical Study

    PubMed Central

    Nauth, Aaron; Aziz, Mina; Tsuji, Matthew; Whelan, Daniel B.; Theodoropoulos, John S.; Zdero, Rad

    2014-01-01

    Objectives: Several recent high profile injuries to elite players in the National Hockey League (NHL) secondary to skate blade lacerations have generated significant interest in these injuries and possible methods to protect against them. These injuries are typically due to direct contact of the skate blade of another player with posterior aspect of the calf resulting in a range of potential injuries to tendons or neurovascular structures. The Achilles tendon is most commonly involved. Kevlar® reinforced socks have recently become available for hockey players to wear and are cited as providing possible protection against such injuries. However, there has been no investigation of the possible protective effects of Kevlar® reinforced socks against skate blade injuries, and it is currently unknown what protective effects, if any, that these socks provide against these injuries. The proposed study sought to address this by conducting a biomechanical investigation of the protective effects of Kevlar® reinforced socks against Achilles tendon injuries in a simulated model of skate blade injury using human cadaver limbs. This novel investigation is the first to address the possible benefits to hockey players of wearing Kevlar® reinforced socks. Methods: Seven matched pairs of human cadaver lower limbs were fitted with a Kevlar ® reinforced sock comprised of 60% Kevlar®/20% Coolmax® polyester/18 % Nylon/12% Spandex (Bauer Elite Performance Skate Sock) on one limb and a standard synthetic sock comprised of 51% polyester/47% nylon/2% spandex (Bauer Premium Performance Skate Sock) on the contralateral limb as a control. Each limb was then mounted on a Materials Testing System (MTS) with the ankle dorsiflexed to 90° and the knee held in full extension using a custom designed jig. Specimens were then impacted with a hockey skate blade directed at the posterior calf, 12 cm above the heel, at an angle of 45° and a speed of 31m/s, to a penetration depth of 4.3 cm, to

  11. Biomechanics of Head Impacts Associated with Diagnosed Concussion in Female Collegiate Ice Hockey Players

    PubMed Central

    Wilcox, Bethany J.; Beckwith, Jonathan G.; Greenwald, Richard M.; Raukar, Neha P.; Chu, Jeffrey J.; McAllister, Thomas W.; Flashman, Laura A.; Maerlender, Arthur C.; Duhaime, Ann-Christine; Crisco, Joseph J.

    2015-01-01

    Epidemiological evidence suggests that female athletes may be at a greater risk of concussion than their male counterparts. The purpose of this study was to examine the biomechanics of head impacts associated with diagnosed concussions in a cohort of female collegiate ice hockey players. Instrumented helmets were worn by 58 female ice hockey players from 2 NCAA programs over a three year period. Kinematic measures of single impacts associated with diagnosed concussion and head impact exposure on days with and without diagnosed concussion were evaluated. Nine concussions were diagnosed. Head impact exposure was greater in frequency and magnitude on days of diagnosed concussions than on days without diagnosed concussion for individual athletes. Peak linear acceleration of head impacts associated with diagnosed concussion in this study are substantially lower than those previously reported in male athletes, while peak rotational accelerations are comparable. Further research is warranted to determine the extent to which female athletes’ biomechanical tolerance to concussion injuries differs from males. PMID:25913243

  12. Diagnosis and Rehabilitation of a Middle Cuneiform Fracture in a Hockey Player.

    PubMed

    Hensley, Craig P; Dirschl, Douglas R

    2016-07-01

    Isolated cuneiform fractures are rare and are often missed on plain radiographs, leading to delayed diagnosis and delayed return to sport. The authors of this study present a 32-year-old male ice hockey player who sustained trauma to his dorsal midfoot from a slap shot. Radiographs were negative for fracture. After inability to wean out of the controlled ankle movement boot, magnetic resonance imaging was ordered, demonstrating a middle cuneiform fracture. The patient was seen in physical therapy, where aquatic therapy, strength training, and cardiovascular conditioning were progressed. He was able to wean out of the controlled ankle movement boot at 7 weeks after injury and return to playing ice hockey. Here, we outline rehabilitation and a diagnostic and rehabilitative algorithm for those who sustain trauma to the dorsal midfoot with suspected fracture. PMID:26945214

  13. Pseudo-polar tilted smectic phases exhibited by bent-core hockey stick shaped molecules.

    PubMed

    Malkar, Deepshika; Sadashiva, B K; Roy, Arun

    2016-06-14

    We report experimental and theoretical studies on two new achiral fluid lamellar phases exhibited by bent-core hockey stick shaped molecules. The packing of these bent-core hockey stick shaped molecules in the layers leads to a pseudo-polar order in these tilted smectic phases. An anticlinic SmCA type stacking of the pseudo-polar layers is observed in the higher temperature smectic phase, while in the lower temperature phase the difference in the azimuthal angles of the tilt directions in successive layers is between zero and π with a randomized tilt organization between the successive layers. The randomness arises due to the sign degeneracy of the azimuthal angle difference of the tilt directions in successive layers. Both of these smectic phases show a strong electro-optic response which can be exploited for potential applications. PMID:27157895

  14. Trends in North American Newspaper Reporting of Brain Injury in Ice Hockey

    PubMed Central

    Cusimano, Michael D.; Sharma, Bhanu; Lawrence, David W.; Ilie, Gabriela; Silverberg, Sarah; Jones, Rochelle

    2013-01-01

    The frequency and potential long-term effects of sport-related traumatic brain injuries (TBI) make it a major public health concern. The culture within contact sports, such as ice hockey, encourages aggression that puts youth at risk of TBI such as concussion. Newspaper reports play an important role in conveying and shaping the culture around health-related behaviors. We qualitatively studied reports about sport-related TBI in four major North American newspapers over the last quarter-century. We used the grounded-theory approach to identify major themes and then did a content analysis to compare the frequency of key themes between 1998–2000 and 2009–2011. The major themes were: perceptions of brain injury, aggression, equipment, rules and regulations, and youth hockey. Across the full study period, newspaper articles from Canada and America portrayed violence and aggression that leads to TBI both as integral to hockey and as an unavoidable risk associated with playing the game. They also condemned violence in ice hockey, criticized the administrative response to TBI, and recognized the significance of TBI. In Canada, aggression was reported more often recently and there was a distinctive shift in portraying protective equipment as a solution to TBI in earlier years to a potential contributing factor to TBI later in the study period. American newspapers gave a greater attention to ‘perception of risks’ and the role of protective equipment, and discussed TBI in a broader context in the recent time period. Newspapers from both countries showed similar recent trends in regards to a need for rule changes to curb youth sport-related TBI. This study provides a rich description of the reporting around TBI in contact sport. Understanding this reporting is important for evaluating whether the dangers of sport-related TBI are being appropriately communicated by the media. PMID:23613957

  15. Trends in North American newspaper reporting of brain injury in ice hockey.

    PubMed

    Cusimano, Michael D; Sharma, Bhanu; Lawrence, David W; Ilie, Gabriela; Silverberg, Sarah; Jones, Rochelle

    2013-01-01

    The frequency and potential long-term effects of sport-related traumatic brain injuries (TBI) make it a major public health concern. The culture within contact sports, such as ice hockey, encourages aggression that puts youth at risk of TBI such as concussion. Newspaper reports play an important role in conveying and shaping the culture around health-related behaviors. We qualitatively studied reports about sport-related TBI in four major North American newspapers over the last quarter-century. We used the grounded-theory approach to identify major themes and then did a content analysis to compare the frequency of key themes between 1998-2000 and 2009-2011. The major themes were: perceptions of brain injury, aggression, equipment, rules and regulations, and youth hockey. Across the full study period, newspaper articles from Canada and America portrayed violence and aggression that leads to TBI both as integral to hockey and as an unavoidable risk associated with playing the game. They also condemned violence in ice hockey, criticized the administrative response to TBI, and recognized the significance of TBI. In Canada, aggression was reported more often recently and there was a distinctive shift in portraying protective equipment as a solution to TBI in earlier years to a potential contributing factor to TBI later in the study period. American newspapers gave a greater attention to 'perception of risks' and the role of protective equipment, and discussed TBI in a broader context in the recent time period. Newspapers from both countries showed similar recent trends in regards to a need for rule changes to curb youth sport-related TBI. This study provides a rich description of the reporting around TBI in contact sport. Understanding this reporting is important for evaluating whether the dangers of sport-related TBI are being appropriately communicated by the media. PMID:23613957

  16. Heart Rate and Energy Expenditure in Division I Field Hockey Players During Competitive Play.

    PubMed

    Sell, Katie M; Ledesma, Allison B

    2016-08-01

    Sell, KM and Ledesma, AB. Heart rate and energy expenditure in Division I field hockey players during competitive play. J Strength Cond Res 30(8): 2122-2128, 2016-The purpose of this study was to quantify energy expenditure and heart rate data for Division I female field hockey players during competitive play. Ten female Division I collegiate field hockey athletes (19.8 ± 1.6 years; 166.4 ± 6.1 cm; 58.2 ± 5.3 kg) completed the Yo-Yo intermittent endurance test to determine maximal heart rate. One week later, all subjects wore a heart rate monitor during a series of 3 matches in an off-season competition. Average heart rate (AvHR), average percentage of maximal heart rate (AvHR%), peak exercise heart rate (PExHR), and percentage of maximal heart rate (PExHR%), time spent in each of the predetermined heart rate zones, and caloric expenditure per minute of exercise (kcalM) were determined for all players. Differences between positions (backs, midfielders, and forwards) were assessed. No significant differences in AvHR, AvHR%, PExHR, PExHR%, and %TM were observed between playing positions. The AvHR% and PExHR% for each position fell into zones 4 (77-93% HRmax) and 5 (>93% HRmax), respectively, and significantly more time was spent in zone 4 compared with zones 1, 2, 3, and 5 across all players (p ≤ 0.05). The kcalM reflected very heavy intensity exercise. The results of this study will contribute toward understanding the sport-specific physiological demands of women's field hockey and has specific implications for the duration and schedule of training regimens. PMID:26808842

  17. TRAINING-INDUCED CHANGES IN DRAG-FLICK TECHNIQUE IN FEMALE FIELD HOCKEY PLAYERS

    PubMed Central

    Gómez, M.; Martín-Casado, L.; Navarro, E.

    2012-01-01

    The penalty corner is one of the most important goal plays in field hockey. The drag-flick is used less by women than men in a penalty corner. The aim of this study was to describe training-induced changes in the drag-flick technique in female field hockey players. Four female players participated in the study. The VICON optoelectronic system (Oxford Metrics, Oxford, UK) measured the kinematic parameters of the drag-flick with six cameras sampling at 250 Hz, prior to and after training. Fifteen shots were captured for each subject. A Wilcoxon test assessed the differences between pre-training and post-training parameters. Two players received specific training twice a week for 8 weeks; the other two players did not train. The proposed drills improved the position of the stick at the beginning of the shot (p < 0.05), the total distance of the shot (p < 0.05) and the rotation radius at ball release (p < 0.01). It was noted that all players had lost speed of the previous run. Further studies should include a larger sample, in order to provide more information on field hockey performance. PMID:24868116

  18. An On-Ice Measurement Approach to Analyse the Biomechanics of Ice Hockey Skating

    PubMed Central

    Buckeridge, Erica; LeVangie, Marc C.; Stetter, Bernd; Nigg, Sandro R.; Nigg, Benno M.

    2015-01-01

    Skating is a fundamental movement in ice hockey; however little research has been conducted within the field of hockey skating biomechanics due to the difficulties of on-ice data collection. In this study a novel on-ice measurement approach was tested for reliability, and subsequently implemented to investigate the forward skating technique, as well as technique differences across skill levels. Nine high caliber (High) and nine low caliber (Low) hockey players performed 30m forward skating trials. A 3D accelerometer was mounted to the right skate for the purpose of stride detection, with the 2nd and 6th strides defined as acceleration and steady-state, respectively. The activity of five lower extremity muscles was recorded using surface electromyography. Biaxial electro-goniometers were used to quantify hip and knee angles, and in-skate plantar force was measured using instrumented insoles. Reliability was assessed with the coefficient of multiple correlation, which demonstrated moderate (r>0.65) to excellent (r>0.95) scores across selected measured variables. Greater plantar-flexor muscle activity and hip extension were evident during acceleration strides, while steady state strides exhibited greater knee extensor activity and hip abduction range of motion (p<0.05). High caliber exhibited greater hip range of motion and forefoot force application (p<0.05). The successful implementation of this on-ice mobile measurement approach offers potential for athlete monitoring, biofeedback and training advice. PMID:25973775

  19. Fatness of female field hockey players: Comparison of estimates with different methods.

    PubMed

    Krzykała, M; Konarski, J M; Malina, R M; Rachwalski, K; Leszczyński, P; Ziółkowska-Łajp, E

    2016-06-01

    The aim of the study was to compare relative body fat (% fat) in female field hockey players using several methods with dual-energy X-ray absorptiometry (DXA) as the reference. Participants were 31 Polish hockey players 16-30 years of age, 17 national and 14 youth level. Percent body fat was estimated by DXA (reference method), conventional and segmental bioelectrical impedance analysis (BIA), and predicted from skinfolds (SKF). National and youth team members did not differ in estimated body fat. Correlations between BIA and skinfold estimates of % fat and DXA % fat though significant, were moderate. Both % fat SKF and % fat SBIA differed significantly from % fat DXA, while estimated % fat BIA and % fat DXA did not differ. Limits of agreement were narrow for conventional BIA (-1.20 to 1.71% fat), followed by segmental BIA (3.72-6.09% fat) and broadest for SKF (5.97-9.28% fat). Differences between DXA % fat and estimated % fat with SKF and SBIA increased from the leanest to fattest athletes, whereas conventional BIA overestimated % fat relative to DXA in the small sample of individuals with low relative fatness and underestimated % fat in individuals with elevated relative fatness. Estimated % fat from conventional BIA most closely approximated DXA % fat in this sample of female field hockey players suggesting that the method may be suitable for field surveys to monitor body composition during the season. PMID:27181627

  20. The Hockey Stick and the Climate Wars: Dispatches From The Front Lines

    NASA Astrophysics Data System (ADS)

    Mann, M. E.

    2011-12-01

    A central figure in the controversy over human-caused climate change has been The Hockey Stick, a simple, easy-to-understand graph my colleagues and I constructed to depict changes in Earth's temperature back to 1000 AD. The graph was featured in the high-profile Summary for Policy Makers of the 2001 report of the Intergovernmental Panel on Climate Change (IPCC), and it quickly became an icon in the debate over human-caused (anthropogenic) climate change. I will tell the story behind the Hockey Stick, using it as a vehicle for exploring broader issues regarding the role of skepticism in science, the uneasy relationship between science and politics, and the dangers that arise when special economic interests and those who do their bidding attempt to skew the discourse over policy-relevant areas of science. In short, I attempt to use the Hockey Stick to cut through the fog of disinformation that has been generated by the campaign to deny the reality of climate change. It is my intent, in so doing, to reveal the very real threat to our future that lies behind it.

  1. Training-induced changes in drag-flick technique in female field hockey players.

    PubMed

    de Subijana, C L; Gómez, M; Martín-Casado, L; Navarro, E

    2012-12-01

    The penalty corner is one of the most important goal plays in field hockey. The drag-flick is used less by women than men in a penalty corner. The aim of this study was to describe training-induced changes in the drag-flick technique in female field hockey players. Four female players participated in the study. The VICON optoelectronic system (Oxford Metrics, Oxford, UK) measured the kinematic parameters of the drag-flick with six cameras sampling at 250 Hz, prior to and after training. Fifteen shots were captured for each subject. A Wilcoxon test assessed the differences between pre-training and post-training parameters. Two players received specific training twice a week for 8 weeks; the other two players did not train. The proposed drills improved the position of the stick at the beginning of the shot (p < 0.05), the total distance of the shot (p < 0.05) and the rotation radius at ball release (p < 0.01). It was noted that all players had lost speed of the previous run. Further studies should include a larger sample, in order to provide more information on field hockey performance. PMID:24868116

  2. Ten years of ice hockey-related-injuries in the German Ice Hockey Federation - A Ten Year Prospective Study/523 International Games -.

    PubMed

    Gröger, A

    2001-12-01

    Since January 1986 all injuries in players of the German national hockey teams (juniors A/B and seniors A/B), which have occurred during international competitions, have been registrated and evaluated by using a strict definition of injury, standardized reporting strategies and diagnosis by the team physician. Patterns of injury have been identified and correlations between position, zone and cause of injury could be analysed and, as a consequence, measures were taken to prevent them. A total of 147 injuries forcing a consecutive absence from the game during 523 international games of the German national teams were reported. During the 10 year period there was a marked decrease of the total number and incidence of injuries. In addition, injury rate and average absence from game time improved. There were more frequent concussions of the brain but the total number of facial injuries dropped after the introduction of a visor and the full face mask especially in junior hockey. The forward was the position most at risk to be injured and most injuries were caused by players contact. PMID:11753779

  3. Trends in reporting of mechanisms and incidence of hip injuries in males playing minor ice hockey in Canada: a cross-sectional study

    PubMed Central

    Ayeni, Olufemi R; Kowalczuk, Marcin; Farag, Jordan; Farrokhyar, Forough; Chu, Raymond; Bedi, Asheesh; Willits, Kevin; Bhandari, Mohit

    2014-01-01

    Background There has been a noted increase in the diagnosis and reporting of sporting hip injuries and conditions in the medical literature but reporting at the minor hockey level is unknown. The purpose of this study is to investigate the trend of reporting hip injuries in amateur ice hockey players in Canada with a focus on injury type and mechanism. Methods A retrospective review of the Hockey Canada insurance database was performed and data on ice hockey hip injuries reported between January 2005 and June 2011 were collected. The study population included all male hockey players from Peewee (aged 11–12 years) to Senior (aged 20+ years) participating in amateur level competition sanctioned by Hockey Canada. Reported cases of ice hockey hip injuries were analyzed according to age, mechanism of injury, and injury subtype. Annual injury reporting rates were determined and using a linear regression analysis trended to determine the change in ice hockey hip injury reporting rate over time. Results One hundred and six cases of ice hockey-related hip injuries were reported in total. The majority of injuries (75.5%) occurred in players aged 15–20 years playing at the Junior level. Most injuries were caused by a noncontact mechanism (40.6%) and strains were the most common subtype (50.0%). From 2005 to 2010, the number of reported hip injuries increased by 5.31 cases per year and the rate of reported hip injury per 1,000 registered players increased by 0.02 cases annually. Conclusion Reporting of hip injuries in amateur ice hockey players is increasing. A more accurate injury reporting system is critical for future epidemiologic studies to accurately document the rate and mechanism of hip injury in amateur ice hockey players. PMID:24966705

  4. Off-Ice Anaerobic Power Does Not Predict On-Ice Repeated Shift Performance in Hockey.

    PubMed

    Peterson, Ben J; Fitzgerald, John S; Dietz, Calvin C; Ziegler, Kevin S; Baker, Sarah E; Snyder, Eric M

    2016-09-01

    Peterson, BJ, Fitzgerald, JS, Dietz, CC, Ziegler, KS, Baker, SE, and Snyder, EM. Off-ice anaerobic power does not predict on-ice repeated shift performance in hockey. J Strength Cond Res 30(9): 2375-2381, 2016-Anaerobic power is a significant predictor of acceleration and top speed in team sport athletes. Historically, these findings have been applied to ice hockey although recent research has brought their validity for this sport into question. As ice hockey emphasizes the ability to repeatedly produce power, single bout anaerobic power tests should be examined to determine their ability to predict on-ice performance. We tested whether conventional off-ice anaerobic power tests could predict on-ice acceleration, top speed, and repeated shift performance. Forty-five hockey players, aged 18-24 years, completed anthropometric, off-ice, and on-ice tests. Anthropometric and off-ice testing included height, weight, body composition, vertical jump, and Wingate tests. On-ice testing consisted of acceleration, top speed, and repeated shift fatigue tests. Vertical jump (VJ) (r = -0.42; r = -0.58), Wingate relative peak power (WRPP) (r = -0.32; r = -0.43), and relative mean power (WRMP) (r = -0.34; r = -0.48) were significantly correlated (p ≤ 0.05) to on-ice acceleration and top speed, respectively. Conversely, none of the off-ice tests correlated with on-ice repeated shift performance, as measured by first gate, second gate, or total course fatigue; VJ (r = 0.06; r = 0.13; r = 0.09), WRPP (r = 0.06; r = 0.14; r = 0.10), or WRMP (r = -0.10; r = -0.01; r = -0.01). Although conventional off-ice anaerobic power tests predict single bout on-ice acceleration and top speed, they neither predict the repeated shift ability of the player, nor are good markers for performance in ice hockey. PMID:26808844

  5. A Novel Approach to Determine Strides, Ice Contact, and Swing Phases During Ice Hockey Skating Using a Single Accelerometer.

    PubMed

    Stetter, Bernd J; Buckeridge, Erica; von Tscharner, Vinzenz; Nigg, Sandro R; Nigg, Benno M

    2016-02-01

    This study presents a new approach for automated identification of ice hockey skating strides and a method to detect ice contact and swing phases of individual strides by quantifying vibrations in 3D acceleration data during the blade-ice interaction. The strides of a 30-m forward sprinting task, performed by 6 ice hockey players, were evaluated using a 3D accelerometer fixed to a hockey skate. Synchronized plantar pressure data were recorded as reference data. To determine the accuracy of the new method on a range of forward stride patterns for temporal skating events, estimated contact times and stride times for a sequence of 5 consecutive strides was validated. Bland-Altman limits of agreement (95%) between accelerometer and plantar pressure derived data were less than 0.019 s. Mean differences between the 2 capture methods were shown to be less than 1 ms for contact and stride time. These results demonstrate the validity of the novel approach to determine strides, ice contact, and swing phases during ice hockey skating. This technology is accurate, simple, effective, and allows for in-field ice hockey testing. PMID:26398967

  6. Posterior approach for arthroscopic treatment of posterolateral impingement syndrome of the ankle in a top-level field hockey player.

    PubMed

    Lohrer, Heinz; Arentz, Sabine

    2004-04-01

    A case history of a 25-year-old field hockey player, a member of the German National Field Hockey Team, is presented. The patient could not remember any specific ankle injury, but since the World Indoor Championship in February 2003, he experienced significant but diffuse pain around the posterior ankle, especially while loading the forefoot in hockey training and competition. For 2 months, the patient was unable to run. Conservative treatment failed, and surgery was performed. Posterior ankle arthroscopy revealed a frayed posterior intermalleolar ligament and meniscoid-like scar tissue at the posterolateral ankle, indicating a posterolateral soft tissue ankle impingement syndrome. A concomitant inflammation of the posterolateral ankle and subtalar synovium was present. After arthroscopic resection and early functional aftertreatment, the patient returned to full high-level sports ability within 2 months. PMID:15067292

  7. The effects of undergarment composition worn beneath hockey protective equipment on high-intensity intermittent exercise.

    PubMed

    Noonan, Benjamin; Stachenfeld, Nina

    2012-09-01

    The purpose of this study was to examine the impact of undergarment composition worn beneath ice hockey protective equipment on thermal homeostasis and power output, during a cycle ergometer exercise protocol designed to simulate the energy expenditure of a hockey game. We hypothesized that the layers of protective equipment would negate the potential thermoregulatory benefits from synthetic "wicking" undergarments but that subjects may feel more comfortable because of the inherent low moisture retention of these fabrics. Eight men (age, 25.4 ± 1.3 year) performed a repeated sprint test before and after a simulated game under typical hockey conditions (12°C; 82% relative humidity). This test was completed twice while wearing full protective equipment and either synthetic (SYN) or cotton (COT) full-length undergarments. During the simulated game, skin temperatures (34.22 ± 0.20°C vs. 34.46 ± 0.16°C) and core temperatures (37.50 ± 0.13°C vs. 37.59 ± 0.14°C) were similar between SYN and COT, respectively. There were also no significant differences found in sweat loss as a percent of body mass, heart rate, plasma lactate, sprint power, or ratings of perceived exertion between SYN and COT, respectively. The SYN retained less water than COT (140 ± 30 vs. 310 ± 30 g; p < 0.05); however, clothing and protective equipment weight gains as a whole were unaffected by the fabric worn (470 ± 110 vs. 590 ± 80 g) for SYN and COT, respectively. There were minimal differences in thermal sensation and undergarment wetness ratings during the simulated game. Thermoregulation and performance was driven more by properties of the layered protective equipment with minimal effects from undergarment composition. PMID:22706578

  8. The Assessment of Airway Maneuvers and Interventions in University Canadian Football, Ice Hockey, and Soccer Players

    PubMed Central

    Delaney, J. Scott; Al-Kashmiri, Ammar; Baylis, Penny-Jane; Troutman, Tracy; Aljufaili, Mahmood; Correa, José A.

    2011-01-01

    Abstract Context: Managing an airway in an unconscious athlete is a lifesaving skill that may be made more difficult by the recent changes in protective equipment. Different airway maneuvers and techniques may be required to help ventilate an unconscious athlete who is wearing full protective equipment. Objective: To assess the effectiveness of different airway maneuvers with football, ice hockey, and soccer players wearing full protective equipment. Design: Crossover study. Setting: University sports medicine clinic. Patients or Other Participants: A total of 146 university varsity athletes, consisting of 62 football, 45 ice hockey, and 39 soccer players. Intervention(s): Athletes were assessed for different airway and physical characteristics. Three investigators then evaluated the effectiveness of different bag-valve-mask (BVM) ventilation techniques in supine athletes who were wearing protective equipment while inline cervical spine immobilization was maintained. Main Outcome Measure(s): The effectiveness of 1-person BVM ventilation (1-BVM), 2-person BVM ventilation (2-BVM), and inline immobilization and ventilation (IIV) was judged by each investigator for each athlete using a 4-point rating scale. Results: All forms of ventilation were least difficult in soccer players and most difficult in football players. When compared with 1-BVM, both 2-BVM and IIV were deemed more effective by all investigators for all athletes. Interference from the helmet and stabilizer were common reasons for difficult ventilation in football and ice hockey players. Conclusions: Sports medicine professionals should practice and be comfortable with different ventilation techniques for athletes wearing full equipment. The use of a new ventilation technique, termed inline immobilization and ventilation, may be beneficial, especially when the number of responders is limited. PMID:21391796

  9. Effect of Increasing Maximal Aerobic Exercise on Serum Muscles Enzymes in Professional Field Hockey Players

    PubMed Central

    Hazar, Muhsin; Otağ, Aynur; Otağ, İlhan; Sezen, Mehmet; Sever, Ozan

    2015-01-01

    Background and Objectives: Exercise results in oxidative enzyme increase and micro-injuries in skeletal muscles. The aim of this study was to investigate the effect of maximal aerobic exercise on serum muscle enzymes in professional field hockey players. This study aims to determine the effect of increasing maximal aerobic exercise on creatine kinase (CK), creatine kinase-MB (CK-MB), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) serum levels. Material and Methods: 31 young professional field hockey players (13 female and 18 male players) volunteered for this study. All participants underwent the shuttle run test. Blood samples were taken from each participant before the shuttle run test. Post test blood samples were taken immediately after exercise and one hour after respectively. Pre and post test CK, CK-MB, AST and ALT values were measured by means of auto analyzer using original kits. Results: The acute post test measure of the CK level increased in male (p=0.002) and female (p=0.00) sportsmen. CK-MB values obtained one hour after the exercise was lower than those before the exercise in males (p=0.02). In females (p=0.017) and males (p=0.05) AST activity significantly increased immediately after exercise and decreased to resting activity 1 h recovery. ALT significantly increased immediately after exercise in female (p=0.03) and male (p=0.00) athletes and after 1 h recovery ALT activities decreased below resting values. Conclusion: The timing and severity of exercise used in our study increased CK values, decreased CK-MB values and AST, ALT values increased in female and male field hockey players. PMID:25948428

  10. Ocular blunt trauma: loss of sight from an ice hockey injury

    PubMed Central

    Morris, D S

    2006-01-01

    A case of ocular blunt trauma is described in which a 17 year old male ice hockey player collided with an opponent during a game. The opponent's stick travelled under the patient's half face visor and struck his left eye causing hyphema, angle recession, lens subluxation, and choroidal rupture over the macula, permanently reducing his vision to counting fingers. Sequelae of ocular blunt trauma are discussed along with methods of injury prevention by addressing players' behaviour and safety equipment. This injury is unlikely to have occurred with properly used full face protection. PMID:16505067

  11. The effect of bovine colostrum supplementation on exercise performance in elite field hockey players.

    PubMed

    Hofman, Zandrie; Smeets, Rolf; Verlaan, George; Lugt, Richard v d; Verstappen, Peter A

    2002-12-01

    In a double-blind, randomized, placebo-controlled study, we investigated the effect of 8 weeks of supplementation with bovine colostrum (Intact) on body composition and exercise performance (5 x 10-m sprint, vertical jump, shuttle-run test, and suicide test). Seventeen female and 18 male elite field hockey players, including players from the Dutch national team, received either 60 g of colostrum or whey protein daily. The 5 x 10-m sprint test performance improved significantly (p =.023) more in the colostrum group [0.64 +/- 0.09 s (mean +/- SEM)] compared to the whey group (0.33 +/- 0.09 s). The vertical jump performance improved more in the colostrum group (2.1 +/- 0.73 cm) compared to the whey group (0.32 +/- 0.82 cm). However, this was not statistically significant (p =.119). There were also no significant differences in changes in body composition and endurance tests between the 2 groups. It is concluded that in elite field hockey players, colostrum supplementation improves sprint performance better than whey. However, there were no differences with regard to body composition or endurance performance. PMID:12500989

  12. Goal orientations of young male ice hockey players and their parents.

    PubMed

    Bergin, David A; Habusta, Steven F

    2004-12-01

    In this study, the researchers investigated the relationship between parent and player dispositional goal orientations associated with playing youth hockey. The authors used the Task and Ego Orientation in Sport Questionnaire (J. L. Duda & J. Whitehead, 1998) to measure task and ego orientation in 123 boys (10-13 years old) and 1 of their parents. Sons rated their own goal orientations for hockey and their perceptions of their parent's goal orientations. Parents rated their goal orientations for their son and their perceptions of their son's goal orientations. Mothers and fathers did not differ in their goal orientations for their son. Travel-team and nontravel-team players did not differ. For ego orientation, the son's self-ratings correlated significantly with the parent's goals for the son, but not for task orientation. Sons reported being significantly more ego-oriented than their parents desired. Sons perceived that their parents had goal orientations similar to their own. The data from this study are congruent with the assertion that parents socialize their children's goal orientations and that ego orientation may be more salient and easily communicated than task orientation. PMID:15636385

  13. Bebop on the Hockey Pitch: Cross-Disciplinary Creativity and Skills Transfer.

    PubMed

    Harrison, Clive M

    2016-01-01

    This paper generalizes task-specific (but dissimilar) skills, from the jazz concert stage and from the hockey field, into the domain of creativity research. What is sought are clues to what skills or creativities are transferable across dissimilar domains. It is argued that certain domain-general skills are transferable across domains, but a domain-general or 'c' creative capacity, is not. Rather than transferring some over-arching capacity to be universally creative, this research highlights factors likely to facilitate successful cross-disciplinary creative expression and posits a correlation between the capacities for discriminant pattern-recognition, task-specific expertise, and sensory data-collection, and the transferability of creativity. Of particular significance is the capacity for informed, selective pattern-breaking based on the 'depth' or 'insider' perspective of the domain expert; such 'expert variation and selective retention' provides creative choices and responses that are likely to be perceived by the field as creative: valuable, novel and surprising. The author is a renowned Australian studio bassist, jazz musician, and music educator who also plays field hockey for Australia at Masters level. His recently completed Ph.D. thesis, based on a performance and composition career spanning 46 years, takes the form of an analytical autoethnography drawn from personal field notes, diaries and interviews as well as published record albums. PMID:26903926

  14. Bebop on the Hockey Pitch: Cross-Disciplinary Creativity and Skills Transfer

    PubMed Central

    Harrison, Clive M.

    2016-01-01

    This paper generalizes task-specific (but dissimilar) skills, from the jazz concert stage and from the hockey field, into the domain of creativity research. What is sought are clues to what skills or creativities are transferable across dissimilar domains. It is argued that certain domain-general skills are transferable across domains, but a domain-general or ‘c’ creative capacity, is not. Rather than transferring some over-arching capacity to be universally creative, this research highlights factors likely to facilitate successful cross-disciplinary creative expression and posits a correlation between the capacities for discriminant pattern-recognition, task-specific expertise, and sensory data-collection, and the transferability of creativity. Of particular significance is the capacity for informed, selective pattern-breaking based on the ‘depth’ or ‘insider’ perspective of the domain expert; such ‘expert variation and selective retention’ provides creative choices and responses that are likely to be perceived by the field as creative: valuable, novel and surprising. The author is a renowned Australian studio bassist, jazz musician, and music educator who also plays field hockey for Australia at Masters level. His recently completed Ph.D. thesis, based on a performance and composition career spanning 46 years, takes the form of an analytical autoethnography drawn from personal field notes, diaries and interviews as well as published record albums. PMID:26903926

  15. A Preliminary Exploration of Concussion and Strength Performance in Youth Ice Hockey Players.

    PubMed

    Reed, N; Taha, T; Monette, G; Keightley, M

    2016-08-01

    The objective of this study was to describe the effect of concussion on upper and lower body strength in children and youth athletes. The participant group was made up of 178 unique male and female ice hockey players (ages 8-14 years). Using a 3-year prospective longitudinal research design, baseline and post-concussion data on hand grip strength, jump tests, and leg maximal voluntary contraction were collected. Using a linear mixed-effects model, no significant differences were found when comparing the baseline strength performance of individuals who went on to experience a concussion and those who did not. When accounting for sex, multiple concussions, and ongoing changes in strength associated with age, weaker hand grip scores were found following concussion while participants were still symptomatic. Lower squat jump heights were achieved while participants were symptomatic as well as when they were no longer self-reporting symptoms associated with concussion. This study represents an initial step towards better understanding strength performance following concussion that may limit the on and off ice performance of youth ice hockey players, as well as predispose youth to subsequent injuries. PMID:27191209

  16. Motivational climate, goal orientation, perceived sport ability, and enjoyment within Finnish junior ice hockey players.

    PubMed

    Jaakkola, T; Ntoumanis, N; Liukkonen, J

    2016-01-01

    The aim of this study was to investigate the relations among situational motivational climate, dispositional approach and avoidance achievement goals, perceived sport ability, and enjoyment in Finnish male junior ice hockey players. The sample comprised 265 junior B-level male players with a mean age of 17.03 years (SD = 0.63). Players filled questionnaires tapping their perceptions of coach motivational climate, achievement goals, perceived sport ability, and enjoyment. For the statistical analysis, players were divided into high and low perceived sport ability groups. Multigroup structural equation modeling (SEM) revealed an indirect path from task-involving motivational climate via task-approach goal to enjoyment. Additionally, SEM demonstrated four other direct associations, which existed in both perceived ability groups: from ego-involving motivational climate to ego-approach and ego-avoidance goals; from ego-approach goal to ego-avoidance goal; and from task-avoidance goal to ego-avoidance goal. Additionally, in the high perceived sport ability group, there was an association from task-involving motivational climate to enjoyment. The results of this study reveal that motivational climate emphasizing effort, personal development and improvement, and achievement goal mastering tasks are significant elements of enjoyment in junior ice hockey. PMID:25648198

  17. Carbon monoxide in indoor ice skating rinks: Evaluation of absorption by adult hockey players

    SciTech Connect

    Levesque, B.; Dewailly, E.; Lavoie, R.; Prud'Homme, D.; Allaire, S. )

    1990-05-01

    We evaluated alveolar carbon monoxide (CO) levels of 122 male, adult hockey players active in recreational leagues of the Quebec City region (Canada), before and after 10 weekly 90-minute games in 10 different rinks. We also determined exposure by quantifying the average CO level in the rink during the games. Other variables documented included age, pulmonary function, aerobic capacity, and smoking status. Environmental concentrations varied from 1.6 to 131.5 parts per million (ppm). We examined the absorption/exposure relationship using a simple linear regression model. In low CO exposure levels, physical exercise lowered the alveolar CO concentration. However, we noted that for each 10 ppm of CO in the ambient air, the players had adsorbed enough CO to raise their carboxyhemoglobin (COHb) levels by 1 percent. This relationship was true both for smokers and non-smokers. We suggest that an average environmental concentration of 20 ppm of CO for the duration of a hockey game (90 minutes) should be reference limit not to be exceeded in indoor skating rinks.

  18. “I Went to a Fight the Other Night and a Hockey Game Broke Out”

    PubMed Central

    Goldschmied, Nadav; Espindola, Samantha

    2013-01-01

    Background: The current study explored the relationship between fighting behavior and passage of time, across games and seasons, in an attempt to assess if violent behavior in hockey is impulsive or intentional. Hypothesis: Before engaging in fighting behavior, players assess the utility of their actions and thus will fight less when the game is on the line (third period) and when champions are crowned (postseason). Methods: An archival exploration utilizing open access databases from multiple Internet sources. Results: During the 2010-2011 National Hockey League (NHL) season, players were significantly less likely to be involved in a fight as the game was coming to a close than in its early stages. In addition, data from the past 10 NHL seasons showed that players were significantly more violent in preseason games than during the regular season. They were also least likely to be involved in a fight during the postseason. Conclusion: The converging evidence suggests that players take into account the penalties associated with fighting and are less likely to engage in violence when the stakes are high, such as at the end of a game or a season. This implies, in turn, that major acts of aggression in the league are more likely to be calculated rather than impulsive. The findings suggest that a more punitive system should diminish fighting behavior markedly. PMID:24427418

  19. King-Devick test normative reference values for professional male ice hockey players.

    PubMed

    Vartiainen, M V; Holm, A; Peltonen, K; Luoto, T M; Iverson, G L; Hokkanen, L

    2015-06-01

    The King-Devick (K-D) test, a measure of processing speed, visual tracking, and saccadic eye movements, has shown promise as a supplemental screening test following concussion. However, limited normative data for this test have been published.The K-D test was administered to 185 professional ice hockey players as a preseason baseline test in seasons 2012-2013 and 2013-2014. Their average age was 23.8 years (median = 22.0 years, range = 16-40 years). The average K-D score was 40.0 s (SD = 6.1 s, range = 24.0-65.7 s). K-D test performance showed no association with age, education, or the number of self-reported previous concussions in this sample. The association between trials 1 and 2 of the K-D test was good (ICC = 0.92, Pearson = 0.93). Normative values of the K-D test for professional male ice hockey players are reported. K-D test performance did not vary by age, education, or concussion history in this study. PMID:25138698

  20. Carbon monoxide in indoor ice skating rinks: evaluation of absorption by adult hockey players.

    PubMed Central

    Lévesque, B; Dewailly, E; Lavoie, R; Prud'Homme, D; Allaire, S

    1990-01-01

    We evaluated alveolar carbon monoxide (CO) levels of 122 male, adult hockey players active in recreational leagues of the Quebec City region (Canada), before and after 10 weekly 90-minute games in 10 different rinks. We also determined exposure by quantifying the average CO level in the rink during the games. Other variables documented included age, pulmonary function, aerobic capacity, and smoking status. Environmental concentrations varied from 1.6 to 131.5 parts per million (ppm). We examined the absorption/exposure relationship using a simple linear regression model. In low CO exposure levels, physical exercise lowered the alveolar CO concentration. However, we noted that for each 10 ppm of CO in the ambient air, the players had adsorbed enough CO to raise their carboxyhemoglobin (COHb) levels by 1 percent. This relationship was true both for smokers and non-smokers. We suggest that an average environmental concentration of 20 ppm of CO for the duration of a hockey game (90 minutes) should be reference limit not to be exceeded in indoor skating rinks. PMID:2327538

  1. The planarity of the stickface motion in the field hockey hit.

    PubMed

    Willmott, Alexander P; Dapena, Jesús

    2012-01-01

    The field hockey hit is an important but poorly understood stroke. In this study, we investigated the planarity of the stickface motion during the downswing to better characterize the kinematics and to assess the suitability of planar pendulum models for simulating the hit. Thirteen experienced female field hockey players were filmed executing hits with a single approach step, and the kinematics of the centre of the stickface were measured. A method was developed for identifying how far back from impact the stickface motion was planar. Orthogonal regression was used to fit least-squares planes to the stickface path during sections of the downswing of varying length, with each section ending at impact. A section was considered planar if the root mean square residual between the stickface path and the fitted plane was less than 0.25% of the distance travelled by the stickface during that period. On average, the stickface motion was planar for the last 83 ± 12% of its downswing path, with the length of the planar section ranging from 1.85 m to 2.70 m. The suitability of a planar model for the stickface motion was supported, but further investigation of the stick and arm kinematics is warranted. PMID:22221186

  2. Bidirectional reflectance spectroscopy 7. The single particle phase function hockey stick relation

    NASA Astrophysics Data System (ADS)

    Hapke, Bruce

    2012-11-01

    The measured volume-average single particle angular scattering functions of a large number of types of particle of interest for planetary regoliths in the visible-near-IR wavelength region can be represented to a reasonable approximation by two-parameter, double Henyey-Greenstein functions. When the two parameters of this function are plotted against one another they are found to be inversely correlated and lie within a restricted zone shaped like a hockey stick within the parameter space. The centroid of the zone is a curve that can be represented by a simple empirical equation. The wide variety of types of particles used to construct the plot implies that this equation may represent most of the particles found in regoliths. This means that when modeling the bidirectional reflectance of a regolith it may be possible to reduce the number of parameters necessary to specify the reflectance, and also to characterize the entire single particle phase function from observations at phase angles less than 90°. Even if the hockey stick relation has a finite width, rather than being a line, it restricts the parameter space that must be searched when fitting data. The curve should also be useful for forward modeling particle phase functions.

  3. Predictors of Length of Career Following Hip Arthroscopy for Femoroacetabular Impingement in Professional Hockey Players

    PubMed Central

    Menge, Travis; Briggs, Karen K.; Philippon, Marc J.

    2016-01-01

    Objectives: Previous studies have shown that professional hockey players return to sport at a high rate following hip arthroscopy. The average length of a National Hockey League (NHL) career has been reported to be 5.5 years, and it is unknown how long players continue to play after hip arthroscopy. The purpose of this study was 1) to determine predictors of length of career in players following hip arthroscopy for treatment of symptomatic femoroacetabular impingement (FAI), and 2) investigate the rate of those who continue to play professional hockey a minimum of 5 years after hip arthroscopy. Methods: Seventy professional hockey players underwent hip arthroscopy for FAI between 2005 and 2010 by a single surgeon. Data was retrieved from NHL.com regarding the duration of each player’s professional career. In addition, position played, draft position, age at time of surgery, and surgical details were also used in data analysis. Results: Our cohort included thirteen players that were centers, 15 defensemen, 20 goalies, and 22 wings. The average overall draft number was 57 (range 1 to 228), and average age at surgery was 27 years (range 17 to 38). Forty of the 70 athletes (57%) continued to play professionally a minimum of 5 years after hip arthroscopy. As of the most recent 2015 season, the average NHL length of career was 13 years (range 8 to 23 years), with an average of 6.9 years played following hip arthroscopy. Therre was no different in length of career and years played when goalies were compared to other players(p=0.760). Length of career and years played after arthroscopy correlated with age at surgery (r=0.799 and r=-0.408). Players who played 5 or more years after arthroscopy were significantly younger than those who did not (25 vs. 30 years, p=0.001). Sixty-five players (93%) had labral repair and 5 (7%) had labral reconstruction. There were no differences in length of career or years played after arthroscopy based on type of labral treatment (p=0

  4. Enforcement of Mouthguard Use and Athlete Compliance in National Collegiate Athletic Association Men's Collegiate Ice Hockey Competition.

    ERIC Educational Resources Information Center

    Hawn, Kristen L.; Visser, Mary Frances; Sexton, Patrick J.

    2002-01-01

    Investigated enforcement patterns and athlete compliance with the National Collegiate Athletic Association rule requiring the wearing of mouthguards in men's collegiate ice hockey games during one season. Surveys of athletic trainers indicated that the use of mouthguards in competition was not consistently enforced by athletic trainers, coaches,…

  5. Effects of Carbohydrate Intake Before and During An Ice Hockey Game on Blood and Muscle Energy Substrates.

    ERIC Educational Resources Information Center

    Simard, Clermont; And Others

    1988-01-01

    Study of the effect of a supplemental carbohydrate intake for seven elite ice hockey players before and during a game demonstrated that the supplement could result in less glycogen usage per distance skated, which had important implications for athletes who may participate in more than one game a day. (Author/CB)

  6. Hockey Concussion Education Project, Part 1: Susceptibility-weighted imaging study in male and female ice hockey players over a single season

    PubMed Central

    Helmer, Karl G.; Pasternak, Ofer; Fredman, Eli; Preciado, Ronny I.; Koerte, Inga K.; Sasaki, Takeshi; Mayinger, Michael; Johnson, Andrew M.; Holmes, Jeffrey D.; Forwell, Lorie; Skopelja, Elaine N.; Shenton, Martha E.; Echlin, Paul S.

    2015-01-01

    Object Concussion, or mild traumatic brain injury (mTBI), is a commonly occurring sports-related injury, especially in contact sports such as hockey. Cerebral microbleeds (CMBs), which are small, hypointense lesions on T2*-weighted images, can result from TBI. The authors use susceptibility-weighted imaging (SWI) to automatically detect small hypointensities that may be subtle signs of chronic and acute damage due to both subconcussive and concussive injury. The goal was to investigate how the burden of these hypointensities change over time, over a playing season, and postconcussion, compared with subjects who did not suffer a medically observed and diagnosed concussion. Methods Images were obtained in 45 university-level adult male and female ice hockey players before and after a single Canadian Interuniversity Sports season. In addition, 11 subjects (5 men and 6 women) underwent imaging at 72 hours, 2 weeks, and 2 months after concussion. To identify subtle changes in brain tissue and potential CMBs, nonvessel clusters of hypointensities on SWI were automatically identified and a hypointensity burden index was calculated for all subjects at the beginning of the season (BOS) and the end of the season (EOS), in addition to postconcussion time points (where applicable). Results A statistically significant increase in the hypointensity burden, relative to the BOS, was observed for male subjects at the 2-week postconcussion time point. A smaller, nonsignificant rise in the burden for all female subjects was also observed within the same time period. The difference in hypointensity burden was also statistically significant for men with concussions between the 2-week time point and the BOS. There were no significant changes in burden for nonconcussed subjects of either sex between the BOS and EOS time points. However, there was a statistically significant difference in the burden between male and female subjects in the nonconcussed group at both the BOS and EOS time

  7. Seasonal Changes in Whole Body and Regional Body Composition Profiles of Elite Collegiate Ice-Hockey Players.

    PubMed

    Prokop, Neal W; Reid, Ryan E R; Andersen, Ross E

    2016-03-01

    Prokop, NW, Reid, RER, and Andersen, RE. Seasonal changes in whole body and regional body composition profiles of elite collegiate ice-hockey players. J Strength Cond Res 30(3): 684-692, 2016-The monitoring of a collegiate hockey player's body composition can reflect fitness characteristics and may help players, coaches, or strength and conditioning specialists optimize physiologic gains during an off-season, whereas simultaneously preventing performance decrements in-season. The purpose of the study was to investigate changes in whole-body and regional-body composition of fat and lean tissue. The body composition profiles of 19 elite Canadian collegiate hockey players were assessed using dual energy X-ray absorptiometry. Players completed end-of-season, preseason, and midseason assessments with questionnaires relating to their off-season and in-season training. Statistically significant changes in body composition profiles were observed between the different time points because players showed various tissue gains and losses depending on the region assessed. Overall, players gained (1.38 kg, p ≤ 0.01) and lost (0.79 kg, p ≤ 0.01) fat tissue during the off-season and in-season, respectively. Players also showed a significant gain of leg lean tissue (0.29 kg, p = 0.02) and loss of arm tissue mass (-0.25 kg, p = 0.02) during the first-half of the competitive season. Several correlations emerged that may provide insight into potential trends that could be more pronounced during longer and more demanding schedules. Collegiate hockey players show changes in body composition during the off-season and in-season. The understanding of body composition profiles, body composition fluctuations, and potential variables that may influence the composition of collegiate hockey players can help coaches and athletic programs tailor their team's training, nutrition, lifestyle, and informative resources to further support their athletes. PMID:26907839

  8. Cardiovascular Prevention in a High Risk Sport, Ice Hockey: Applications in Wider Sports Physical Therapy Practice

    PubMed Central

    2006-01-01

    Although acute myocardial infarction and sudden cardiac death are relatively rare occurrences in athletics, cardiovascular accidents do occur. This manuscript presents information on the cardiovascular risks in athletics. In addition, information is provided on screening for cardiovascular risk – including history taking, chart review, physical examination – and the appropriate guidelines on the treatment of athletes found to be at risk. For the purpose of this article, the sport of ice hockey is used to illustrate the subject matter and highlight the behaviors in sport that carry cardiovascular risk. Physical therapists have ethical and legal responsibility to undertake the necessary screening procedures to recognize and respond to any signs of cardiovascular risk in their clients. PMID:21522221

  9. [Analysis of the behavior of the coach in relation to violence in minor league hockey].

    PubMed

    Trudel, P; Guertin, D; Bernard, D; Boileau, R; Marcotte, G

    1991-06-01

    The purpose of this study was to verify if, during games, the behavior of ice hockey coaches at the bantam level tends to incite players to use roughness and to infringe upon the rules of the game, as the Néron report (1977) states. The video recording of 27 games using a split-screen technique made it possible to view simultaneously the players in action as well as the coaches' behavior. Analysis of the videotapes revealed that the coaches (n = 11) at the bantam level often exhort their players to put more intensity in their physical contacts (legal body checking), but they more often encouraged them to control themselves and avoid penalties. In general, the coaches displayed very little behavior that encouraged violent actions from the players. PMID:1647855

  10. Ice hockey lung - a case of mass nitrogen dioxide poisoning in the Czech Republic.

    PubMed

    Brat, Kristian; Merta, Zdenek; Plutinsky, Marek; Skrickova, Jana; Stanek, Miroslav

    2013-01-01

    Nitrogen dioxide (NO₂) is a toxic gas, a product of combustion in malfunctioning ice-resurfacing machines. NO₂ poisoning is rare but potentially lethal. The authors report a case of mass NO₂ poisoning involving 15 amateur ice hockey players in the Czech Republic. All players were treated in the Department of Respiratory Diseases at Brno University Hospital in November 2010 - three as inpatients because they developed pneumonitis. All patients were followed-up until November 2011. Complete recovery in all but one patient was achieved by December 2010. None of the 15 patients developed asthma-like disease or chronic cough. Corticosteroids appeared to be useful in treatment. Electric-powered ice-resurfacing machines are preferable in indoor ice skating arenas. PMID:24032121

  11. Ice hockey lung – a case of mass nitrogen dioxide poisoning in the Czech Republic

    PubMed Central

    Brat, Kristian; Merta, Zdenek; Plutinsky, Marek; Skrickova, Jana; Ing, Miroslav Stanek

    2013-01-01

    Nitrogen dioxide (NO2) is a toxic gas, a product of combustion in malfunctioning ice-resurfacing machines. NO2 poisoning is rare but potentially lethal. The authors report a case of mass NO2 poisoning involving 15 amateur ice hockey players in the Czech Republic. All players were treated in the Department of Respiratory Diseases at Brno University Hospital in November 2010 – three as inpatients because they developed pneumonitis. All patients were followed-up until November 2011. Complete recovery in all but one patient was achieved by December 2010. None of the 15 patients developed asthma-like disease or chronic cough. Corticosteroids appeared to be useful in treatment. Electric-powered ice-resurfacing machines are preferable in indoor ice skating arenas. PMID:24032121

  12. CHRONIC LEG PAIN IN A DIVISION II FIELD HOCKEY PLAYER: A CASE REPORT

    PubMed Central

    Snowden, Julie; Becker, Jonathan A.; Hazle, Charles

    2014-01-01

    Exertional compartment syndromes in athletes represent a diagnostic and management challenge for clinicians. The clinical presentation of exertional compartment syndrome is similar to other more common musculoskeletal disorders. A lack of special tests or unique diagnostic identifiers for use in decision making by out‐patient clinicians complicates early recognition of this disorder and may delay optimal management. The purpose of this case report is to retrospectively explore the clinical presentation and the decision‐making during the course of care of a field hockey athlete eventually determined to have exertional compartment syndrome. Suggestions to assist in recognition and guidance in patient management are included as well as the procedures required for differential diagnosis. Procedures utilized during conservative care are also described in detail. Level of Evidence: 5 (Single Case Report) PMID:24567863

  13. Conservative management of symptomatic Carpal Bossing in an elite hockey player: a case report

    PubMed Central

    Kissel, Peter

    2009-01-01

    Objective: To present the characteristics and create awareness of symptomatic carpal bossing and discuss potential etiologies and the role of conservative management through the presentation of an athlete with traumatic onset of symptomatic carpal bossing. Clinical features: This case report outlines the presentation and conservative management of an elite eighteen year old hockey player with symptomatic carpal bossing after a traumatic on ice collision. Carpal bossing is a bony, dorsal prominence in the quadrangular joint of the wrist that is inconsistently symptomatic. Intervention and outcome: A conservative treatment plan consisting of education, reassurance, avoidance of aggravation, and soft tissue therapy allowed return to play in two weeks without restrictions or need for surgical consultation. Conclusion: With inconsistent recurrence rates and surgical complications, the role of conservative management for symptomatic carpal bossing deserves further exploration. The conservative practitioner should be aware of the signs and symptoms of symptomatic carpal bossing to institute suitable treatment. PMID:20037693

  14. Chiral random grain boundary phase of achiral hockey-stick liquid crystals.

    PubMed

    Chen, Dong; Wang, Haitao; Li, Min; Glaser, Matthew A; Maclennan, Joseph E; Clark, Noel A

    2014-12-01

    A disordered chiral conglomerate, the random grain boundary (RGB) phase, has been observed below the smectic A liquid crystal phase of an achiral, hockey-stick molecule. In cells, the RGB phase appears dark between crossed polarizers but decrossing the polarizers reveals large left- and right-handed chiral domains with opposite optical rotation. Freeze-fracture transmission electron microscopy reveals that the RGB phase is an assembly of randomly oriented blocks of smectic layers, an arrangement that distinguishes the RGB from the dark, chiral conglomerate phases of bent-core mesogens. X-ray diffraction indicates that there is significant layer shrinkage at the SmA-RGB phase transition, which is marked by the collapse of layers with long-range order into small, randomly oriented smectic blocks. PMID:25310113

  15. Recreational ice hockey injuries in adult non-checking leagues: a United States perspective.

    PubMed

    Caputo, Pasqualino; Mattson, Douglas J

    2005-03-01

    The purpose of this study was to analyze injuries among adult recreational ice hockey players. This was an observational prospective cohort study with data collected on injuries sustained during one season in the adult recreational ice hockey leagues of Oneida County, NY. The injury incidence rate was found to be 12.2/1000 player-exposures. The most common anatomic region injured was the head/neck/face (35%). Collisions were most often reported as the mechanism of injury (44%). Fracture was the most common diagnosis. Of players wearing face protection (full cage or shield, or partial visor/half shield), none suffered facial injuries, while all facial injuries reported were to players not wearing facial protection. The concussion rate was 1.1/1000 player-exposures. A lack of protective equipment was associated with 38% of injuries and 24% of injuries involved penalties. A history of prior injuries was found in 89% of injured players with 28% re-injuring the same body part. This study's findings suggested various strategies to address player injuries such as mandatory full facial protection and shoulder pads, strict enforcement of game rules, and game rule modifications (no body checking). Further research is needed on the role of preventive rehabilitation in players with previous injury history. Key PointsThe injury incidence rate was found to be 12.2/1000 player-exposures, similar to previous Canadian literature.The concussion rate was 1.1/1000 player-exposures.38% of injuries involved a lack of protective equipment and 24% of injuries involved penalties.Full facial protection and shoulder pads should be compulsory.Strict enforcement of game rules is necessary.History of prior injuries was found in 89% of injured players. PMID:24431962

  16. Magnetic Resonance Imaging and Intra-articular Findings After Anterior Cruciate Ligament Injuries in Ice Hockey Versus Other Sports

    PubMed Central

    Kluczynski, Melissa A.; Kang, Jeansol V.; Marzo, John M.; Bisson, Leslie J.

    2016-01-01

    Background: The prevalence of comorbid knee pathology has been examined for sports-related anterior cruciate ligament (ACL) injuries, but it has not been examined in ice hockey players. Purpose: To compare concomitant bone bruising, collateral ligament injuries, and intra-articular injuries in ACL injuries suffered during ice hockey versus other sports. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 20 patients with ACL injuries sustained during ice hockey were identified from a prospective registry, of which 95% were male and 90% had a contact mechanism of injury (MOI). Thirteen cases and 46 controls who sustained ACL injuries from ice hockey and other sports, respectively, were included. Inclusion criteria for cases and controls were male sex, contact MOI, no prior knee surgery, magnetic resonance imaging (MRI) within 6 weeks of injury, and surgery within 3 months of injury. Age, body mass index (BMI), MRI findings (bone bruising, medial and lateral collateral ligament [MCL, LCL] injuries), and arthroscopic findings (meniscus tears, chondral injuries) were compared for cases versus controls using t tests or exact chi-square tests. Results: Age (22.9 ± 8.8 vs 23.4 ± 10.4 years, P = .88) and BMI ≥25 kg/m2 (50% vs 65.9%, P = .66) did not differ between cases and controls. Cases had less lateral bone bruising (lateral femoral condyle: 54.6% vs 93%, P = .01; lateral tibial plateau: 72.7% vs 93%, P = .09) and no medial bone bruising (medial femoral condyle: 0% vs 7%, P = .06; medial tibial plateau: 0% vs 32.6%, P = .05) compared with controls. Cases had less frequent lateral meniscus tears than controls (23.1% vs 58.5%, P = .05). There were no significant differences in MCL (40% vs 31.2%, P = .77), LCL (0% vs 3.9%, P > .999), medial meniscus tears (7.7% vs 37%, P = .08), and chondral injuries (10% vs 9.4%, P > .999) for cases versus controls. Conclusion: Male ice hockey players with ACL injuries had less lateral femoral condyle and

  17. Tsunami Hockey

    NASA Astrophysics Data System (ADS)

    Weinstein, S.; Becker, N. C.; Wang, D.; Fryer, G. J.

    2013-12-01

    An important issue that vexes tsunami warning centers (TWCs) is when to cancel a tsunami warning once it is in effect. Emergency managers often face a variety of pressures to allow the public to resume their normal activities, but allowing coastal populations to return too quickly can put them at risk. A TWC must, therefore, exercise caution when cancelling a warning. Kim and Whitmore (2013) show that in many cases a TWC can use the decay of tsunami oscillations in a harbor to forecast when its amplitudes will fall to safe levels. This technique should prove reasonably robust for local tsunamis (those that are potentially dangerous within only 100 km of their source region) and for regional tsunamis (whose danger is limited to within 1000km of the source region) as well. For ocean-crossing destructive tsunamis such as the 11 March 2011 Tohoku tsunami, however, this technique may be inadequate. When a tsunami propagates across the ocean basin, it will encounter topographic obstacles such as seamount chains or coastlines, resulting in coherent reflections that can propagate great distances. When these reflections reach previously-impacted coastlines, they can recharge decaying tsunami oscillations and make them hazardous again. Warning center scientists should forecast sea-level records for 24 hours beyond the initial tsunami arrival in order to observe any potential reflections that may pose a hazard. Animations are a convenient way to visualize reflections and gain a broad geographic overview of their impacts. The Pacific Tsunami Warning Center has developed tools based on tsunami simulations using the RIFT tsunami forecast model. RIFT is a linear, parallelized numerical tsunami propagation model that runs very efficiently on a multi-CPU system (Wang et al, 2012). It can simulate 30-hours of tsunami wave propagation in the Pacific Ocean at 4 arc minute resolution in approximately 6 minutes of real time on a 12-CPU system. Constructing a 30-hour animation using 1 minute simulated time steps takes approximately 50 minutes on the same system. These animations are generated quickly enough to provide decision support for emergency managers whose coastlines may be impacted by the tsunami several hours later. Tsunami reflections can also aid in determining the source region for those tsunamis generated by non-seismic mechanisms without a clear source such as meteotsunamis, tsunamis generated by meteorological phenomena. A derecho that crossed the New Jersey coast and entered the Atlantic Ocean at approximately 1500 UTC June 13, 2013 generated a meteotsunami that struck the northeast coast of the US causing several injuries. A DART sensor off Montauk, NY, recorded tsunami waves approximately 200 minutes apart. We show how the arrival times of the tsunamis recorded by this DART can help to constrain the source region of the meteotsunami. We also examine other reflections produced by the Haida Gwaii 2012, Tohoku 2011, and other tsunamis.

  18. A Cool Sport Full of Physics

    ERIC Educational Resources Information Center

    Hache, Alain

    2008-01-01

    Of all sports, ice hockey is possibly the one with the widest array of physics elements in it. The game provides many examples that can bring physics to life in the classroom. Ice hockey (or just "hockey" as many Canadians would say) sees athletes sliding on ice at high speeds and in various ways, shooting and slapping pucks, and colliding against…

  19. The prevalence and severity of injuries in field hockey drag flickers: a retrospective cross-sectional study.

    PubMed

    Ng, Leo; Sherry, Dorianne; Loh, Wei Bing; Sjurseth, Andreas Myhre; Iyengar, Shrikant; Wild, Catherine; Rosalie, Simon

    2016-09-01

    The drag flick is the preferred method of scoring during a penalty corner in field hockey. Performing the drag flick requires a combination of strength, coordination and timing, which may increase susceptibility to injuries. However, injury prevalence in drag flickers has not previously been investigated. Therefore, this study compared the injury prevalence and severity of lower limb and lower back injuries between drag flickers and non-drag flickers in field hockey. A total of 432 local, national and international adult field hockey players (242 males, 188 females) completed an online questionnaire to retrospectively determine the 3-month prevalence and severity of ankle, knee, hip and lower back injuries. Of this group, 140 self-identified as drag flickers and 292 as non-drag flickers. The results showed that drag flickers had significantly higher prevalence of hip (OR: 1.541; 95% CI: 1.014, 2.343) and lower back injury (OR: 1.564; 95% CI: 1.034, 2.365) compared to non-drag flickers. No significant differences were observed between drag flickers and non-drag flickers in injury prevalence at the ankle and knee. There were no significant between-group differences in injury severity scores. Overall, the prevalence of hip and lower back injuries was significantly higher in drag flickers compared to non-drag flickers. PMID:26760078

  20. Novice performance of ultrasound-guided needle advancement: standard 38-mm transducer vs 25-mm hockey stick transducer.

    PubMed

    Davies, T; Townsley, P; Jlala, H; Dowling, M; Bedforth, N; Hardman, J G; McCahon, R A

    2012-08-01

    The optimal method to develop expertise in ultrasound-guided regional anaesthesia is unknown. Studies of laryngoscopic expertise in novices demonstrate that the choice of laryngoscope affects performance. In this study, we aimed to compare the effect of two different linear array transducers (38-mm standard vs 25-mm hockey stick) on novice performance of ultrasound-guided needle advancement. Following randomisation, participants watched a video model of expert performance of ultrasound-guided needle advancement. Recruits performed the modelled task on a turkey breast model. The median (IQR [range]) composite error score was statistically significantly larger for participants in the hockey stick transducer group compared with the standard transducer group; 10.0 (7.3-14.3 [2.5-29.0]) vs 7.5 (4.5-10.0 [2.0-28.0]) respectively, (p = 0.01). This study has demonstrated that performance of ultrasound-guided needle advancement by novice operators after simple video instruction is better (as assessed using a composite error score) with a standard 38-mm transducer than with a 25-mm hockey stick transducer. PMID:22506607

  1. Can injury in major junior hockey players be predicted by a pre-season functional movement screen – a prospective cohort study

    PubMed Central

    Dossa, Khaled; Cashman, Glenn; Howitt, Scott; West, Bill; Murray, Nick

    2014-01-01

    Background: The Functional Movement Screen (FMS) is a tool that is commonly used to predict the occurrence of injury. Previous studies have shown that a score of 14 or less (with a maximum possible score of 21) successfully predicted future injury occurrence in athletes. No studies have looked at the use of the FMS to predict injuries in hockey players. Objective: To see if injury in major junior hockey players can be predicted by a preseason FMS. Methods: A convenience sample of 20 hockey players was scored on the FMS prior to the start of the hockey season. Injuries and number of man-games lost for each injury were documented over the course of the season. Results: The mean FMS score was 14.7+/−2.58. Those with an FMS score of ≤14 were not more likely to sustain an injury as determined by the Fisher’s exact test (one-tailed, P = 0.32). Conclusion: This study did not support the notion that lower FMS scores predict injury in major junior hockey players. PMID:25550667

  2. Test-Retest Reliability of Computerized Neurocognitive Testing in Youth Ice Hockey Players.

    PubMed

    Womble, Melissa N; Reynolds, Erin; Schatz, Philip; Shah, Kishan M; Kontos, Anthony P

    2016-06-01

    Computerized neurocognitive tests are frequently used to assess pediatric sport-related concussions; however, only 1 study has focused on the test-retest reliability of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) in high school athletes and age influences have largely been ignored. Therefore, the purpose was to investigate the test-retest reliability of ImPACT and underlying age influences in a pediatric population. Two hundred (169 men and 31 women) youth ice hockey players completed ImPACT before/after a 6-month season. Reliability was assessed using Pearson correlation coefficients, intraclass correlation coefficients (ICCs), and regression-based methods (RBz). ICCs for the sample ranged from .48 to .75 (single)/.65 to .86 (average). In general, the older athletes (15-18: Single/Average ICCs = .35-.75/.52-.86) demonstrated greater reliability across composites than the younger athletes (11-14: Single/Average ICCs = .54-.63/.70-.77). Although there was variation in athletes' performance across two test administrations, RBz revealed that only a small percentage of athletes performed beyond 80%, 90%, and 95% confidence intervals. Statistical metrics demonstrated reliability coefficients for ImPACT composites in a pediatric sample similar to previous studies, and also revealed important age-related influences. PMID:27084734

  3. Why do sleeping nematodes adopt a hockey-stick-like posture?

    PubMed

    Tramm, Nora; Oppenheimer, Naomi; Nagy, Stanislav; Efrati, Efi; Biron, David

    2014-01-01

    A characteristic posture is considered one of the behavioral hallmarks of sleep, and typically includes functional features such as support for the limbs and shielding of sensory organs. The nematode C. elegans exhibits a sleep-like state during a stage termed lethargus, which precedes ecdysis at the transition between larval stages. A hockey-stick-like posture is commonly observed during lethargus. What might its function be? It was previously noted that during lethargus, C. elegans nematodes abruptly rotate about their longitudinal axis. Plausibly, these "flips" facilitate ecdysis by assisting the disassociation of the old cuticle from the new one. We found that body-posture during lethargus was established using a stereotypical motor program and that body bends during lethargus quiescence were actively maintained. Moreover, flips occurred almost exclusively when the animals exhibited a single body bend, preferentially in the anterior or mid section of the body. We describe a simple biomechanical model that imposes the observed lengths of the longitudinally directed body-wall muscles on an otherwise passive elastic rod. We show that this minimal model is sufficient for generating a rotation about the anterior-posterior body axis. Our analysis suggests that posture during lethargus quiescence may serve a developmental role in facilitating flips and that the control of body wall muscles in anterior and posterior body regions are distinct. PMID:25025212

  4. Changes in white matter microstructure in ice hockey players with a history of concussion: a diffusion tensor imaging study

    PubMed Central

    Sasaki, Takeshi; Pasternak, Ofer; Mayinger, Michael; Muehlmann, Marc; Savadjiev, Peter; Bouix, Sylvain; Kubicki, Marek; Fredman, Eli; Dahlben, Brian; Helmer, Karl; Johnson, Andrew M.; Holmes, Jeff D.; Forwell, Lori A.; Skopelja, Elaine; Shenton, Martha E.; Echlin, Paul; Koerte, Inga K.

    2016-01-01

    Object The aim of this study was to examine the brain’s white matter microstructure using magnetic resonance diffusion tensor imaging (DTI) in ice hockey players with a history of clinically symptomatic concussion compared to those players without a history of concussion. Methods Sixteen players with a history of concussion (Concussed Group; mean age: 21.7 ± 1.5 years; 6 female) and eighteen players without a history of concussion (Non-Concussed Group; mean age: 21.3 ± 1.8 years, 10 female) underwent 3T DTI at the end of the Canadian Interuniversity Sports ice hockey season 2011–2012. Tract-based spatial statistics (TBSS) was used to test for group differences in fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and trace. Cognitive evaluation was performed using the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) and the Sport Concussion Assessment Tool-2 (SCAT2). Results TBSS revealed a significant increase in FA and AD, and a significant decrease in RD and trace in several brain regions in the Concussed group, compared with the Non-concussed group (p < 0.05). The regions with increased FA and decreased RD and trace included the right posterior limb of the internal capsule, the right corona radiata, and the right temporal lobe. Increased AD was observed in a small area in the left corona radiata. DTI measures neither correlated with the ImPACT nor SCAT2. Conclusion The results of the current study indicate that a history of concussion may result in alterations of the brain’s white matter microstructure in ice hockey players. Increased FA based on decreased RD may reflect neuroinflammatory or neuroplastic processes of the brain responding to brain trauma. Future studies are needed that include a longitudinal analysis of the brain’s structure and function following a concussion in order to elucidate further the complex time course of DTI changes and their clinical meaning. PMID:24471841

  5. Muscle Oxygen Changes following Sprint Interval Cycling Training in Elite Field Hockey Players

    PubMed Central

    Jones, Ben; Hamilton, David K.; Cooper, Chris E.

    2015-01-01

    This study examined the effects of Sprint Interval Cycling (SIT) on muscle oxygenation kinetics and performance during the 30-15 intermittent fitness test (IFT). Twenty-five women hockey players of Olympic standard were randomly selected into an experimental group (EXP) and a control group (CON). The EXP group performed six additional SIT sessions over six weeks in addition to their normal training program. To explore the potential training-induced change, EXP subjects additionally completed 5 x 30s maximal intensity cycle testing before and after training. During these tests near-infrared spectroscopy (NIRS) measured parameters; oxyhaemoglobin + oxymyoglobin (HbO2+ MbO2), tissue deoxyhaemoglobin + deoxymyoglobin (HHb+HMb), total tissue haemoglobin (tHb) and tissue oxygenation (TSI %) were taken. In the EXP group (5.34±0.14 to 5.50±0.14m.s-1) but not the CON group (pre = 5.37±0.27 to 5.39±0.30m.s-1) significant changes were seen in the 30-15IFT performance. EXP group also displayed significant post-training increases during the sprint cycling: ΔTSI (−7.59±0.91 to −12.16±2.70%); ΔHHb+HMb (35.68±6.67 to 69.44±26.48μM.cm); and ΔHbO2+ MbO2 (−74.29±13.82 to −109.36±22.61μM.cm). No significant differences were seen in ΔtHb (−45.81±15.23 to −42.93±16.24). NIRS is able to detect positive peripheral muscle oxygenation changes when used during a SIT protocol which has been shown to be an effective training modality within elite athletes. PMID:25807517

  6. Head Impact Exposure in Male and Female Collegiate Ice Hockey Players

    PubMed Central

    Wilcox, Bethany J.; Beckwith, Jonathan G.; Greenwald, Richard M.; Chu, Jeffrey J.; McAllister, Thomas W.; Flashman, Laura A.; Maerlender, Arthur C.; Duhaime, Ann-Christine; Crisco, Joseph J.

    2014-01-01

    The purpose of this study was to quantify head impact exposure (frequency, location and magnitude of head impacts) for individual male and female collegiate ice hockey players and to investigate differences in exposure by sex, player position, session type, and team. Ninety-nine (41 male, 58 female) players were enrolled and 37,411 impacts were recorded over three seasons. Frequency of impacts varied significantly by sex (males: 287 per season, females: 170, p<0.001) and helmet impact location (p<0.001), but not by player position (p=0.088). Head impact frequency also varied by session type; both male and female players sustained more impacts in games than in practices (p<0.001), however the magnitude of impacts did not differ between session types. There was no difference in 95th percentile peak linear acceleration between sexes (males: 41.6g, females: 40.8g), but 95th percentile peak rotational acceleration and HITsp (a composite severity measure) were greater for males than females (4424, 3409 rad/s2, and 25.6, 22.3, respectively). Impacts to the back of the helmet resulted in the greatest 95th percentile peak linear accelerations for males (45.2g) and females (50.4g), while impacts to the side and back of the head were associated with the greatest 95th percentile peak rotational accelerations (males: 4719, 4256 rad/sec2, females: 3567, 3784 rad/sec2 respectively). It has been proposed that reducing an individual’s head impact exposure is a practical approach for reducing the risk of brain injuries. Strategies to decrease an individual athlete’s exposure need to be sport and gender specific, with considerations for team and session type. PMID:24210478

  7. Pre-competition hormonal and psychological levels of elite hockey players: relationship to the "home advantage".

    PubMed

    Carré, Justin; Muir, Cameron; Belanger, Joey; Putnam, Susan K

    2006-10-30

    The home advantage is a robust phenomenon that occurs in the world of amateur and professional sport. Athletic teams have been shown to win significantly more games in their home venue as compared to their opponents' venue. Studies have suggested that the home advantage may be related to familiarity with the facility, increased crowd density and even pre-competition hormonal levels. The present study investigated pre-competition physiological and psychological states of elite hockey players in the home and away venues. Physiological measures included salivary cortisol and testosterone, which were assessed using enzyme immunoassays. In addition, pre-competition psychological states were assessed using the Competitive State Anxiety Inventory-2. Physiological measures indicated that the players had significantly higher pre-game testosterone when playing in their home venue as compared to their opponents' venue (t(13)=2.29, p=0.04); however, this difference was not due to a pre-game rise in testosterone while competing at home. Furthermore, players showed a trend toward higher pre-game cortisol when playing in their home venue (t(13)=1.96, p=0.07). Psychological measures indicated that players were more self-confident when playing in their home venue (t(13)=2.8, p=0.008) and also had higher somatic (t(13)=2.3, p=0.02) and cognitive anxiety (t(13)=1.87, p=0.04) when playing in their opponents' venue. The present study supports the notion that there are differences in pre-competition hormonal and psychological states that may play a key role in the "home advantage". PMID:16934844

  8. Analysis of international competition and training in men's field hockey by global positioning system and inertial sensor technology.

    PubMed

    White, Andrew D; MacFarlane, Niall G

    2015-01-01

    This study assessed the relative demands of elite field hockey training and competition to determine whether familiar exercise prescription strategies provide an appropriate training stimulus. Sixteen elite male field hockey players (age, 25 ± 4 years; body mass, 70.9 ± 6.6 kg; and maximal oxygen consumption, 61.0 ± 2.1 ml·kg·min [mean ± SD]) participated in the study. Seventy-five elite level competition and 37 training analyses from 8 games and 4 training sessions were obtained. Training duration was longer than competition and covered a greater total distance (109 ± 2.5 vs. 74 ± 0.3 minutes and 7318 ± 221 vs. 5868 ± 75 m; p < 0.001 in both). The distance covered sprinting and running at high intensity was not different between training and competition (114 ± 6 vs. 116 ± 9 m when sprinting and 457 ± 6 vs. 448 ± 7 m for high-intensity running). More high-intensity accelerations were performed during training than in competition (37 ± 3 vs. 20 ± 2). Despite having lower predicted aerobic capacity and covering less distance in competition than in some previous studies, these data support the suggestion that it is high-intensity activity that differentiates international level competition and further suggests that international players can replicate the intensity of competition during small-sided games. PMID:24978837

  9. Kinematic adaptations in sprint acceleration performances without and with the constraint of holding a field hockey stick.

    PubMed

    Wdowski, Maximilian M; Gittoes, Marianne J R

    2013-06-01

    The aim of this study was to investigate the technique adaptations made when performing sprint-based tasks without (free condition) and with (constrained condition) the constraints of carrying a field hockey stick. Three free and three constrained maximal sprint accelerations were performed by 18 experienced university male field hockey players (age = 20 +/- 1 years, body mass = 73.3 +/- 7.1 kg, and stature = 1.78 +/- 0.05 m). An automatic motion analysis system tracked sagittal plane active marker locations (200 Hz). M sprint velocity during the 18-22 m (free: 8.03 +/- 0.43 m/s; constrained: 7.93 +/- 0.36 m/s) interval was significantly (p = 0.03) different between free and constrained conditions. While the M stride length and stride frequency was similar between free and constrained conditions in the 2-13 m capture volume, the free condition elicited a 0.10 m/s faster (p = 0.03) stride velocity. Further significant differences were found between free and constrained kinematic profiles (p < or = 0.05) for the hip angular velocity at touchdown during the 2-12 m interval of the sprints and in the overall sprint technique coordination between free and constrained conditions. Performance and technique adaptations indicated that sprint-training protocols for field sports should integrate specific equipment constraints to ensure explicit replication of the mechanical demands of the skills underpinning superior performance. PMID:23898687

  10. Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

    ERIC Educational Resources Information Center

    Vescovi, Jason D.

    2016-01-01

    Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,…

  11. Using Elite Athletes to Promote Drug Abstinence: Evaluation of a Single-Session School-Based Drug Use Prevention Program Delivered by Junior Hockey Players

    ERIC Educational Resources Information Center

    Wong, Jennifer

    2016-01-01

    School-based substance use prevention programs are a common method to approaching drug use in youths. Project SOS is a single-session drug prevention program developed by police officers and delivered by elite junior hockey players to students in grades 6 and 7. The current study evaluates the effects of Project SOS at achieving its objectives of…

  12. The Epidemiology of Hip/Groin Injuries in National Collegiate Athletic Association Men’s and Women’s Ice Hockey

    PubMed Central

    Dalton, Sara L.; Zupon, Alyssa B.; Gardner, Elizabeth C.; Djoko, Aristarque; Dompier, Thomas P.; Kerr, Zachary Y.

    2016-01-01

    Background: There is limited research regarding the epidemiology of hip/groin injuries in ice hockey, the majority of which is restricted to time-loss injuries only. Purpose: To describe the epidemiology of hip/groin injuries in collegiate men’s and women’s ice hockey from 2009-2010 through 2014-2015. Study Design: Descriptive epidemiology study. Methods: Hip/groin injury data from the National Collegiate Athletic Association Injury Surveillance Program (NCAA-ISP) during the 2009-2010 through 2014-2015 seasons were analyzed. Injury rates, rate ratios (RRs), and injury proportion ratios (IPRs) were reported with 95% confidence intervals (CIs). Results: During the 2009-2010 through 2014-2015 seasons, 421 and 114 hip/groin injuries were reported in men’s and women’s ice hockey, respectively, leading to injury rates of 1.03 and 0.78 per 1000 athlete-exposures (AEs), respectively. The hip/groin injury rate was greater in men than in women (RR, 1.32; 95% CI, 1.08-1.63). In addition, 55.6% and 71.1% of hip/groin injuries in men’s and women’s ice hockey, respectively, were non–time loss (NTL) injuries (ie, resulted in participation restriction time <24 hours); 7.6% and 0.9%, respectively, were severe (ie, resulted in participation restriction time >3 weeks). The proportion of hip/groin injuries that were NTL injuries was greater in women than in men (IPR, 1.28; 95% CI, 1.11-1.48). Conversely, the proportion of hip/groin injuries that were severe was greater in men than in women (IPR, 8.67; 95% CI, 1.20-62.73). The most common hip/groin injury diagnosis was strain (men, 67.2%; women, 76.3%). Also, 12 (2.9%) and 3 (2.6%) cases of hip impingement were noted in men’s and women’s ice hockey, respectively. Conclusion: Hip/groin injury rates were greater in men’s than in women’s ice hockey. Time loss varied between sexes, with men sustaining more injuries with time loss over 3 weeks. Despite increasing concerns of femoroacetabular impingement in ice hockey

  13. Iron Metabolism in Field Hockey Players During an Annual Training Cycle

    PubMed Central

    Podgórski, Tomasz; Kryściak, Jakub; Konarski, Jan; Domaszewska, Katarzyna; Durkalec-Michalski, Krzysztof; Strzelczyk, Ryszard; Pawlak, Maciej

    2015-01-01

    Post-physical training changes in iron metabolism in the human body often occur. To fully describe these processes, fifteen male Polish National Team field hockey players (age 27.7 ± 5.2 years, body mass 72.8 ± 7.6 kg and body height 177.1 ± 5.7 cm) were examined in three phases of an annual training cycle: preparatory (T1), competitive (T2) and transition (T3). To assess aerobic fitness, maximal oxygen uptake (VO2max) was evaluated. Based on the iron concentration, the changes in total iron binding capacity (TIBC), unsaturated iron binding capacity (UIBC) and other selected haematological indicators (haemoglobin, erythrocytes, mean corpuscular haemoglobin - MCH) in iron metabolism were estimated. The average values of maximum oxygen uptake increased from 54.97 ± 3.62 ml·kg−1·min−1 in T1 to 59.93 ± 3.55 ml·kg−1·min−1 in T2 (p<0.05) and then decreased to 56.21 ± 4.56 ml·kg−1·min−1 in T3 (p<0.05). No statistically significant changes in the erythrocyte count were noted. The MCH and haemoglobin concentration decreased between T1 and T2. The maximal exercise test caused a significant (p<0.05) increase in the plasma iron concentration during the competition and transition phases. Progressive but non-significant increases in resting iron concentration, TIBC and UIBC in the analysed annual training cycle were noted. To show global changes in iron metabolism in the human body, it is necessary to determine additional variables, i.e. UIBC, TIBC, haemoglobin, MCH or the erythrocyte count. The direction of changes in iron metabolism depends on both the duration and intensity of the physical activity and the fitness level of the subjects. Dietary intake of iron increases the level of this trace element and prevents anaemia associated with training overloads. PMID:26557195

  14. Temperature dependences of the electrooptical properties of rodlike nematic liquid crystals doped with hockey-stick-shaped liquid crystals

    NASA Astrophysics Data System (ADS)

    Yeo, Sunggu; Srivastava, Anoop Kumar; Lee, Hyojin; Lee, Ji-Hoon; Choi, E.-Joon

    2016-01-01

    We investigated the temperature dependences of the dielectric anisotropy, birefringence, order parameter, splay elastic constant, and rotational viscosity of rodlike nematic liquid crystals (RLCs) doped with hockey-stick-shaped liquid crystals (HLCs). Although the order parameter of the HLC-RLC mixtures was similar to that of the pure RLC, the dielectric anisotropy and the birefringence of the mixtures were decreased or increased depending on the structure of the HLC molecule. In addition, the activation energies of the mixtures were different, which implies that the intramolecular structure of the HLC molecule had more influence on the electrooptical properties of the HLC-RLC binary mixtures than the inter-molecular interaction between the HLC and the RLC molecules.

  15. Chronic cough and dyspnea in ice hockey players after an acute exposure to combustion products of a faulty ice resurfacer.

    PubMed

    Kahan, Erika S; Martin, Ubaldo J; Spungen, Steve; Ciccolella, David; Criner, Gerard J

    2007-01-01

    The aim of this study was to characterize pulmonary function and radiologic testing in ice hockey players after exposure to combustion products of a faulty ice resurfacer. Our patients were 16 previously healthy hockey players who developed chronic cough and dyspnea after exposure. Symptom questionnaires, pulmonary function tests (PFTs), bronchoprovocation testing, cardiopulmonary exercise testing, high-resolution computed tomography (CT) imaging, and impulse oscillometry (IOS) were all used. A normal group was used for PFTs and IOS controls. Patients had onset of cough within 72 h of exposure. Ninety-two percent complained of dyspnea, 75% chest pain, and 33% hemoptysis. Eight percent were initially hospitalized for their symptoms. Eighty-five percent were treated with systemic steroids and 39% with inhaled bronchodilators. Six months postexposure, 54% complained of cough and 46% complained of dyspnea on exertion. All patients had normal PFTs; 8.3% had a significant bronchodilator response. All had normal exercise tests (mean VO2max = 90 +/- 3% predicted) and chest CTs. With IOS, 80% had a significant bronchodilator response (decreased resistance > 12% and SD score > 1; mean change = 21.1 +/- 9.9%, mean SD score = 3.1 +/- 2.5). No correlation existed between changes in resistance or reactance and spirometric values. Patient symptoms correlated significantly with bronchodilator response on IOS resistance (R=0.61, p=0.03). More than 50% of patients exposed to the combustion products of a faulty ice resurfacer remained symptomatic six months after exposure. Despite persistence of symptoms, conventional pulmonary function tests and radiologic evaluation did not reveal airway abnormalities. IOS showed evidence of increased airway resistance and small-airway disease, which correlated with patient symptoms. PMID:17294334

  16. The ability of parents to accurately report concussion occurrence in their bantam-aged minor hockey league children

    PubMed Central

    Coghlin, Craig J; Myles, Bryan D; Howitt, Scott D.

    2009-01-01

    Objective: The objective of this study was to assess the ability of hockey parents/guardians to recognize concussion symptoms in their 13–14 year old (Bantam-aged) children. Outcome Measures: The outcome measures were the ability to recognize different signs and symptoms listed on the Sport Concussion Assessment Tool (SCAT) as well as 8 detractors consisting of signs and symptoms not associated with post concussive syndrome. Additional questions assessing the parents’ knowledge of concussion management and recognition abilities were also posed. Participants: Parents of Bantam-aged minor hockey league athletes volunteered for the study. Methods: The study investigators distributed questionnaires during the warm up period or following their children’s games to the study participants. Following questionnaire completion, participants were provided with an information package outlining the correct signs and symptoms of concussion. Results: The mean number of correct responses to signs and symptoms of concussion was 21.25/25 for the mothers and 20.41/25 for the fathers. The mean number of detractors identified as not associated with concussion was 5.93/8 for the mothers and 4.85/8 for the fathers, indicating that mothers were more capable of recognizing the signs and symptoms than fathers. An analysis of variance including sporting experience in the model did not strengthen the relationship between parent gender and test outcome. Conclusion: This investigation revealed that there is still a disconnect in regards to key components of recognizing a concussion, such as difficulty with sleep, disorientation symptoms, and emotional irritability. Mothers have displayed an ability to better differentiate between true and false signs and symptoms of concussion as compared to fathers. Continued education and awareness of mild traumatic brain injury in athletes should address the misconceptions amongst parents in regards to the true signs and symptoms of a concussion. PMID

  17. Skin conditions in figure skaters, ice-hockey players and speed skaters: part I - mechanical dermatoses.

    PubMed

    Tlougan, Brook E; Mancini, Anthony J; Mandell, Jenny A; Cohen, David E; Sanchez, Miguel R

    2011-09-01

    Figure skaters, ice-hockey players and speed skaters experience a range of dermatologic conditions and tissue-related injuries on account of mechanical trauma, infectious pathogens, inflammatory processes and environmental factors related to these competitive pursuits. Sports medicine practitioners, family physicians, dermatologists and coaches should be familiar with these skin conditions to ensure timely and accurate diagnosis and management of affected athletes. This review is Part I of a subsequent companion review and provides a comprehensive review of mechanical dermatoses experienced by ice-skating athletes, including skater's nodules and its variants, pump bumps, piezogenic pedal papules, talon noir, skate/lace bite, friction bullae, corns and calluses, onychocryptosis, skater's toe and skate blade-induced lacerations. These injuries result from friction, shear forces, chronic pressure and collisions with surfaces that occur when athletes endure repetitive jump landings, accelerated starts and stops and other manoeuvres during rigorous training and competition. Ill-fitting skates, improper lacing techniques and insufficient lubrication or protective padding of the foot and ankle often contribute to the development of skin conditions that result from these physical and mechanical stresses. As we will explain, simple measures can frequently prevent the development of these conditions. The treatment of skater's nodules involves reduction in chronic stimulation of the malleoli, and the use of keratolytics and intralesional steroid injections; if malleolar bursitis develops, bursa aspirations may be required. Pump bumps, which result from repetitive friction posteriorly, can be prevented by wearing skates that fit correctly at the heel. Piezogenic pedal papules may be treated conservatively by using heel cups, compressive stockings and by reducing prolonged standing. Talon noir usually resolves without intervention within several weeks. The treatment of skate

  18. The role of visual perception measures used in sports vision programmes in predicting actual game performance in Division I collegiate hockey players.

    PubMed

    Poltavski, Dmitri; Biberdorf, David

    2015-01-01

    Abstract In the growing field of sports vision little is still known about unique attributes of visual processing in ice hockey and what role visual processing plays in the overall athlete's performance. In the present study we evaluated whether visual, perceptual and cognitive/motor variables collected using the Nike SPARQ Sensory Training Station have significant relevance to the real game statistics of 38 Division I collegiate male and female hockey players. The results demonstrated that 69% of variance in the goals made by forwards in 2011-2013 could be predicted by their faster reaction time to a visual stimulus, better visual memory, better visual discrimination and a faster ability to shift focus between near and far objects. Approximately 33% of variance in game points was significantly related to better discrimination among competing visual stimuli. In addition, reaction time to a visual stimulus as well as stereoptic quickness significantly accounted for 24% of variance in the mean duration of the player's penalty time. This is one of the first studies to show that some of the visual skills that state-of-the-art generalised sports vision programmes are purported to target may indeed be important for hockey players' actual performance on the ice. PMID:25142869

  19. Multidisciplinary approach to non-surgical management of inguinal disruption in a professional hockey player treated with platelet-rich plasma, manual therapy and exercise: a case report

    PubMed Central

    St-Onge, Eric; MacIntyre, Ian G.; Galea, Anthony M.

    2015-01-01

    Objective: To present the clinical management of inguinal disruption in a professional hockey player and highlight the importance of a multidisciplinary approach to diagnosis and management. Clinical Features: A professional hockey player with recurrent groin pain presented to the clinic after an acute exacerbation of pain while playing hockey. Intervention: The patient received a clinical diagnosis of inguinal disruption. Imaging revealed a tear in the rectus abdominis. Management included two platelet-rich plasma (PRP) injections to the injured tissue, and subsequent manual therapy and exercise. The patient returned to his prior level of performance in 3.5 weeks. Discussion: This case demonstrated the importance of a multidisciplinary team and the need for advanced imaging in athletes with groin pain. Summary: Research quality concerning the non-surgical management of inguinal disruption remains low. This case adds evidence that PRP, with the addition of manual therapy and exercise may serve as a relatively quick and effective non-surgical management strategy. PMID:26816415

  20. Laboratory- and field-based testing as predictors of skating performance in competitive-level female ice hockey

    PubMed Central

    Henriksson, Tommy; Vescovi, Jason D; Fjellman-Wiklund, Anncristine; Gilenstam, Kajsa

    2016-01-01

    Objectives The purpose of this study was to examine whether field-based and/or laboratory-based assessments are valid tools for predicting key performance characteristics of skating in competitive-level female hockey players. Design Cross-sectional study. Methods Twenty-three female ice hockey players aged 15–25 years (body mass: 66.1±6.3 kg; height: 169.5±5.5 cm), with 10.6±3.2 years playing experience volunteered to participate in the study. The field-based assessments included 20 m sprint, squat jump, countermovement jump, 30-second repeated jump test, standing long jump, single-leg standing long jump, 20 m shuttle run test, isometric leg pull, one-repetition maximum bench press, and one-repetition maximum squats. The laboratory-based assessments included body composition (dual energy X-ray absorptiometry), maximal aerobic power, and isokinetic strength (Biodex). The on-ice tests included agility cornering s-turn, cone agility skate, transition agility skate, and modified repeat skate sprint. Data were analyzed using stepwise multivariate linear regression analysis. Linear regression analysis was used to establish the relationship between key performance characteristics of skating and the predictor variables. Results Regression models (adj R2) for the on-ice variables ranged from 0.244 to 0.663 for the field-based assessments and from 0.136 to 0.420 for the laboratory-based assessments. Single-leg tests were the strongest predictors for key performance characteristics of skating. Single leg standing long jump alone explained 57.1%, 38.1%, and 29.1% of the variance in skating time during transition agility skate, agility cornering s-turn, and modified repeat skate sprint, respectively. Isokinetic peak torque in the quadriceps at 90° explained 42.0% and 32.2% of the variance in skating time during agility cornering s-turn and modified repeat skate sprint, respectively. Conclusion Field-based assessments, particularly single-leg tests, are an adequate

  1. NON-SURGICAL TREATMENT OF A PROFESSIONAL HOCKEY PLAYER WITH THE SIGNS AND SYMPTOMS OF SPORTS HERNIA: A CASE REPORT

    PubMed Central

    Woodward, J. Scott; Parker, Andrew; MacDonald, Robert M.

    2012-01-01

    Study Design: Case Report Background: Injury or weakness of lower abdominal attachments and the posterior inguinal wall can be symptoms of a “sports hernia” and an underlying source of groin pain. Although several authors note conservative treatment as the initial step in the management of this condition, very little has been written on the specific description of non-surgical measures. Most published articles favoring operative care describe poor results related to conservative management; however they fail to report what treatment techniques comprise non-operative management. Case Presentation: The subject of this case report is a professional ice hockey player who sustained an abdominal injury in a game, which was diagnosed as a sports hernia. Following the injury, structured conservative treatment emphasized core control and stability with progressive peripheral demand challenges. Intrinsic core control emphasis continued throughout the treatment progression and during the functional training prior to return to sport. Outcome: The player completed his recovery with return to full competition seven weeks post injury, and continues to compete in the NHL seven years later. Discussion: Surgical intervention has been shown to be effective in the treatment of the “sports hernia.” However it is the authors' opinion that conservative care emphasizing evaluation of intrinsic core muscular deficits and rehabilitation directed at addressing these deficits is an appropriate option, and should be considered prior to surgical intervention. PMID:22319682

  2. Sediment quality thresholds: Estimates from hockey stick regression of liver lesion prevalence in English sole (Pleuronectes vetulus)

    SciTech Connect

    Horness, B.H.; Lomax, D.P.; Johnson, L.L.; Myers, M.S.; Pierce, S.M.; Collier, T.K.

    1998-01-01

    Comprehensive, integrative assessments of coastal sediment quality are best effected by using large, diverse data sets that include measures of biological dysfunction observed in association with chronic exposure to sediment contaminants. Under the auspices of the National Oceanic and Atmospheric Administration`s National Status and Trends Program, the National Benthic Surveillance Project accumulated a database of synoptic sediment contaminant concentrations and indices of biological effects that were measured in indigenous animals collected during field surveys conducted from 1984 to 1994. This compilation of data provided the opportunity to develop a new approach for determining sediment quality criteria to add to the current repertoire of environmental assessment tools. Using a two-segment hockey stick regression, statistically significant chemical thresholds of biological effects were estimated for hepatic lesion prevalences in English sole (Pleuronectes vetulus, formerly Parophrys vetulus) in relation to sediment concentrations of polycyclic aromatic hydrocarbons. These threshold estimates are notably lower than many of those reported for other techniques. Application of this relatively simple dose-response model to subacute, chronic effects that are involved in pepatocarcinogenesis and associated with sediment toxicant content (1) reflects the link between toxicopathic disease progression and conditions observed in benthic fish exposed to contaminants and (2) provides endpoints for assessing sediment quality contaminant concentrations that are not necessarily acutely fatal but may have long-term health implications for populations that are chronically exposed.

  3. Generic Hockey-Stick Model for Estimating Benchmark Dose and Potency: Performance Relative to BMDS and Application to Anthraquinone.

    PubMed

    Bogen, Kenneth T

    2011-01-01

    Benchmark Dose Model software (BMDS), developed by the U.S. Environmental Protection Agency, involves a growing suite of models and decision rules now widely applied to assess noncancer and cancer risk, yet its statistical performance has never been examined systematically. As typically applied, BMDS also ignores the possibility of reduced risk at low doses ("hormesis"). A simpler, proposed Generic Hockey-Stick (GHS) model also estimates benchmark dose and potency, and additionally characterizes and tests objectively for hormetic trend. Using 100 simulated dichotomous-data sets (5 dose groups, 50 animals/group), sampled from each of seven risk functions, GHS estimators performed about as well or better than BMDS estimators, and a surprising observation was that BMDS mis-specified all of six non-hormetic sampled risk functions most or all of the time. When applied to data on rodent tumors induced by the genotoxic chemical carcinogen anthraquinone (AQ), the GHS model yielded significantly negative estimates of net potency exhibited by the combined rodent data, suggesting that-consistent with the anti-leukemogenic properties of AQ and structurally similar quinones-environmental AQ exposures do not likely increase net cancer risk. In addition to its simplicity and flexibility, the GHS approach offers a unified, consistent approach to quantifying environmental chemical risk. PMID:21731536

  4. Biomechanical analysis of the penalty-corner drag-flick of elite male and female hockey players.

    PubMed

    López de Subijana, Cristina; Juárez, Daniel; Mallo, Javier; Navarro, Enrique

    2010-06-01

    The aim of this study was to analyse the kinematic sequencing in the penalty-corner drag-flicks of elite male and female field hockey players of international calibre. Thirteen participants (one skilled male drag-flicker and six male and six female elite players) participated in the study. An optoelectronic motion analysis system was used to capture the drag-flicks with six cameras, sampling at 250 Hz. Select ground reaction force parameters were obtained from a force platform which registered the last support of the front foot. Twenty trials were captured from each subject. Both player groups showed significantly (p < 0.05) smaller ball velocity at release, peak angular velocity of the pelvis, and negative and positive peak angular velocities of the stick than the skilled subject. Normalised ground reaction forces of the gender groups were also smaller than that of the skilled drag-flicker. By comparing these players we established that the cues of the skill level are a wide stance, a whipping action (rapid back lift) of the stick followed by an explosive sequential movement of the pelvis, upper trunk and stick. PMID:20806843

  5. Alterations in head dynamics with the addition of a hockey helmet and face shield under inertial loading.

    PubMed

    Smith, A W; Bishop, P J; Wells, R P

    1985-06-01

    The effect of a hockey helmet and face shield on the head and neck during inertial loading was studied. A Hybrid III Anthropometric Test Dummy (ATD) was struck from both the front and rear by a spring-loaded, instrumented striker moving at 2.9 ms-1. Data were collected from a triaxial force transducer mounted at the atlanto-occipital (a-o) junction of the ATD, a load cell in the striker, and by cinematography (250 fps). Angular kinematics of the head and moments of force about the a-o junction were determined along with impact force levels. When compared to a bare-head condition, the addition of a helmet and face shield caused an increase in head angular displacement (20-40%) but did not affect head angular acceleration. Axial and shear forces at the a-o junction did not change appreciably with the addition of a helmet and face shield. A triphasic pattern was evident for the neck moments including a small phase which represented a seating of the headform on the nodding blocks of the uppermost ATD neck segment, and two larger phases of opposite polarity which represented the motion of the head relative to the trunk during the first 350 ms after impact. No substantial differences were apparent between the helmeted and non-helmeted trials. The magnitudes of forces and moments found in the present study were well within tolerance levels reported by others (Melvin, 1979; Cheng et al., 1982). It was concluded that the increase in angular displacement of the head, with the addition of a helmet and face shield, does not place the wearer in a position of increased risk of cervical spine trauma. PMID:4017154

  6. Serum SNTF Increases in Concussed Professional Ice Hockey Players and Relates to the Severity of Postconcussion Symptoms.

    PubMed

    Siman, Robert; Shahim, Pashtun; Tegner, Yelverton; Blennow, Kaj; Zetterberg, Henrik; Smith, Douglas H

    2015-09-01

    Biomarkers for diffuse axonal injury could have utilities for the acute diagnosis and clinical care of concussion, including those related to sports. The calpain-derived αII-spectrin N-terminal fragment (SNTF) accumulates in axons after traumatic injury and increases in human blood after mild traumatic brain injury (mTBI) in relation to white matter abnormalities and persistent cognitive dysfunction. However, SNTF has never been evaluated as a biomarker for sports-related concussion. Here, we conducted longitudinal analysis of serum SNTF in professional ice hockey players, 28 of whom had a concussion, along with 45 players evaluated during the preseason, 17 of whom were also tested after a concussion-free training game. Compared with preseason levels, serum SNTF increased at 1 h after concussion and remained significantly elevated from 12 h to 6 days, before declining to preseason baseline. In contrast, serum SNTF levels were unchanged after training. In 8 players, postconcussion symptoms resolved within a few days, and in these cases serum SNTF levels were at baseline. On the other hand, for the 20 players withheld from play for 6 days or longer, serum SNTF levels rose from 1 h to 6 days postconcussion, and at 12-36 h differed significantly from the less-severe concussions (p=0.004). Serum SNTF exhibited diagnostic accuracy for concussion, especially so with delayed return to play (area under the curve=0.87). Multi-variate analyses of serum SNTF and tau improved the diagnostic accuracy, the relationship with the delay in return to play, and the temporal window beyond tau alone. These results provide evidence that blood SNTF, a biomarker for axonal injury after mTBI, may be useful for diagnosis and prognosis of sports-related concussion, as well as for guiding neurobiologically informed decisions on return to play. PMID:25419578

  7. Effect of hockey-stick-shaped molecules on the critical behavior at the nematic to isotropic and smectic-A to nematic phase transitions in octylcyanobiphenyl.

    PubMed

    Chakraborty, Anish; Chakraborty, Susanta; Das, Malay Kumar

    2015-03-01

    In the field of soft matter research, the characteristic behavior of both nematic-isotropic (N-I) and smectic-A nematic(Sm-A N) phase transitions has gained considerable attention due to their several attractive features. In this work, a high-resolution measurement of optical birefringence (Δn) has been performed to probe the critical behavior at the N-I and Sm-A N phase transitions in a binary system comprising the rodlike octylcyanobiphenyl and a laterally methyl substituted hockey-stick-shaped mesogen, 4-(3-n-decyloxy-2-methyl-phenyliminomethyl)phenyl 4-n-dodecyloxycinnamate. For the investigated mixtures, the critical exponent β related to the limiting behavior of the nematic order parameter close to the N-I phase transition has come out to be in good conformity with the tricritical hypothesis. Moreover, the yielded effective critical exponents (α', β', γ') characterizing the critical fluctuation near the Sm-A N phase transition have appeared to be nonuniversal in nature. With increasing hockey-stick-shaped dopant concentration, the Sm-A N phase transition demonstrates a strong tendency to be driven towards a first-order nature. Such a behavior has been accounted for by considering a modification of the effective intermolecular interactions and hence the related coupling between the nematic and smectic order parameters, caused by the introduction of the angular mesogenic molecules. PMID:25871134

  8. Effect of hockey-stick-shaped molecules on the critical behavior at the nematic to isotropic and smectic-A to nematic phase transitions in octylcyanobiphenyl

    NASA Astrophysics Data System (ADS)

    Chakraborty, Anish; Chakraborty, Susanta; Das, Malay Kumar

    2015-03-01

    In the field of soft matter research, the characteristic behavior of both nematic-isotropic (N -I ) and smectic-A nematic (Sm -A N ) phase transitions has gained considerable attention due to their several attractive features. In this work, a high-resolution measurement of optical birefringence (Δ n ) has been performed to probe the critical behavior at the N -I and Sm -A N phase transitions in a binary system comprising the rodlike octylcyanobiphenyl and a laterally methyl substituted hockey-stick-shaped mesogen, 4-(3-n -decyloxy-2-methyl-phenyliminomethyl)phenyl 4-n -dodecyloxycinnamate. For the investigated mixtures, the critical exponent β related to the limiting behavior of the nematic order parameter close to the N -I phase transition has come out to be in good conformity with the tricritical hypothesis. Moreover, the yielded effective critical exponents (α', β', γ') characterizing the critical fluctuation near the Sm -A N phase transition have appeared to be nonuniversal in nature. With increasing hockey-stick-shaped dopant concentration, the Sm -A N phase transition demonstrates a strong tendency to be driven towards a first-order nature. Such a behavior has been accounted for by considering a modification of the effective intermolecular interactions and hence the related coupling between the nematic and smectic order parameters, caused by the introduction of the angular mesogenic molecules.

  9. Teardrop fracture following head-first impact in an ice hockey player: Case report and analysis of injury mechanisms

    PubMed Central

    Yue, James J.; Scott, David L.

    2016-01-01

    Background We report a case of a young male athlete who sustained a three column displaced teardrop fracture of the C5 vertebra due to a head-first impact in hockey, suffered neurapraxia, yet made full neurological recovery. This full recovery was in sharp contrast to multiple case series which reported permanent quadriplegia in the vast majority of teardrop fracture patients. We investigate the etiology and biomechanical mechanisms of injury. Methods Admission imaging revealed the teardrop fracture which consisted of: a frontal plane fracture which separated an anterior quadrilateral-shaped fragment from the posterior vertebral body; a vertical fracture of the posterior vertebral body in the sagittal plane; and incomplete fractures of the neural arch that initiated superiorly at the anterior aspect of the spinous process and left lamina adjacent to the superior facet. Epidural hematoma in the region of the C5 vertebra was observed in addition to disc and ligamentous disruptions at C4-5 and C5-6. Our patient was ultimately treated surgically with anterior fusion from C4 through C6 and subsequently with bilateral posterior fusion at C5-6. Results The injuries were caused by high-energy axial compression with the neck in a pre-flexed posture. The first fracture event consisted of the anterior vertebral body fragment being sheared off of the posterior fragment under the compression load due in part to the sagittal plane concavity of the C5 inferior endplate. The etiology of the vertical fracture of the posterior vertebral body fragment in the sagittal plane was consistent with a previously described hypothesis of the mechanistic injury events. First, the C4-5 disc height decreased under load which increased its hoop stress. Next, this increased hoop stress transferred lateral forces to the C5 uncinate processes which caused their outward expansion. Finally, the outward expansion of the uncinate processes caused the left and right sides of the vertebral body to split

  10. Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players

    PubMed Central

    Janot, Jeffrey M.; Beltz, Nicholas M.; Dalleck, Lance D.

    2015-01-01

    The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15) and women (n = 11) hockey players (age = 20.5 ± 1.4 years) participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ), 40-yd dash (36.58m), 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop), and 1.5 mile (2.4km) run. Results indicated that 40-yd dash (36.58m), VJ, 1.5 mile (2.4km) run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time) and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1) slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time) + (0.005 x 1.5 mile run), 2) fastest repeat skate time = 9.762 - (0.089 x VJ) - (0.998 x 40-yd dash time), 3) average repeat skate time = 7.770 + (1.041 x 40-yd dash time) - (0.63 x VJ) + (0.003 x 1.5 mile time), and 4) 47.85 m speed test = 7.707 - (0.050 x VJ) - (0.01 x % drop). It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players. Key points The 40-yd dash (36.58m) and vertical jump tests are significant predictors of on-ice skating performance specific to speed. In addition to 40-yd dash and vertical jump, the 1.5 mile (2.4km) run for time and percent power drop from the Wingate anaerobic power test were also significant predictors of skating performance that incorporates the aspect of recovery from skating activity. Due to the specificity of selected off-ice variables as predictors of on-ice performance, coaches

  11. Myelin Water Fraction Is Transiently Reduced after a Single Mild Traumatic Brain Injury--A Prospective Cohort Study in Collegiate Hockey Players.

    PubMed

    Wright, Alexander D; Jarrett, Michael; Vavasour, Irene; Shahinfard, Elham; Kolind, Shannon; van Donkelaar, Paul; Taunton, Jack; Li, David; Rauscher, Alexander

    2016-01-01

    Impact-related mild traumatic brain injuries (mTBI) are a major public health concern, and remain as one of the most poorly understood injuries in the field of neuroscience. Currently, the diagnosis and management of such injuries are based largely on patient-reported symptoms. An improved understanding of the underlying pathophysiology of mTBI is urgently needed in order to develop better diagnostic and management protocols. Specifically, dynamic post-injury changes to the myelin sheath in the human brain have not been examined, despite 'compromised white matter integrity' often being described as a consequence of mTBI. In this preliminary cohort study, myelin water imaging was used to prospectively evaluate changes in myelin water fraction, derived from the T2 decay signal, in two varsity hockey teams (45 players) over one season of athletic competition. 11 players sustained a concussion during competition, and were scanned at 72 hours, 2 weeks, and 2 months post-injury. Results demonstrated a reduction in myelin water fraction at 2 weeks post-injury in several brain areas relative to preseason scans, including the splenium of the corpus callosum, right posterior thalamic radiation, left superior corona radiata, left superior longitudinal fasciculus, and left posterior limb of the internal capsule. Myelin water fraction recovered to pre-season values by 2 months post-injury. These results may indicate transient myelin disruption following a single mTBI, with subsequent remyelination of affected neurons. Myelin disruption was not apparent in the athletes who did not experience a concussion, despite exposure to repetitive subconcussive trauma over a season of collegiate hockey. These findings may help to explain many of the metabolic and neurological deficits observed clinically following mTBI. PMID:26913900

  12. Myelin Water Fraction Is Transiently Reduced after a Single Mild Traumatic Brain Injury – A Prospective Cohort Study in Collegiate Hockey Players

    PubMed Central

    Vavasour, Irene; Shahinfard, Elham; Kolind, Shannon; van Donkelaar, Paul; Taunton, Jack; Li, David; Rauscher, Alexander

    2016-01-01

    Impact-related mild traumatic brain injuries (mTBI) are a major public health concern, and remain as one of the most poorly understood injuries in the field of neuroscience. Currently, the diagnosis and management of such injuries are based largely on patient-reported symptoms. An improved understanding of the underlying pathophysiology of mTBI is urgently needed in order to develop better diagnostic and management protocols. Specifically, dynamic post-injury changes to the myelin sheath in the human brain have not been examined, despite ‘compromised white matter integrity’ often being described as a consequence of mTBI. In this preliminary cohort study, myelin water imaging was used to prospectively evaluate changes in myelin water fraction, derived from the T2 decay signal, in two varsity hockey teams (45 players) over one season of athletic competition. 11 players sustained a concussion during competition, and were scanned at 72 hours, 2 weeks, and 2 months post-injury. Results demonstrated a reduction in myelin water fraction at 2 weeks post-injury in several brain areas relative to preseason scans, including the splenium of the corpus callosum, right posterior thalamic radiation, left superior corona radiata, left superior longitudinal fasciculus, and left posterior limb of the internal capsule. Myelin water fraction recovered to pre-season values by 2 months post-injury. These results may indicate transient myelin disruption following a single mTBI, with subsequent remyelination of affected neurons. Myelin disruption was not apparent in the athletes who did not experience a concussion, despite exposure to repetitive subconcussive trauma over a season of collegiate hockey. These findings may help to explain many of the metabolic and neurological deficits observed clinically following mTBI. PMID:26913900

  13. Editorial Commentary: Helping Those Who Seek the Company of "Lord Stanley": Hockey Players and Hip Injuries Highlight the Current State and Future Challenges in Understanding, Treating, and Preventing Nonarthritic Hip Disease.

    PubMed

    Christoforetti, John

    2016-09-01

    The state of the art in caring for athletic hip injuries requires comprehensive understanding of dynamic sport-specific biomechanical demands, accurate musculoskeletal diagnosis, and a mindset towards matching hip structure with functional demand at all levels of play. The sport of hockey presents a unique opportunity to review these fundamentals of modern management and illuminates the way towards future understanding of the cause of common nonarthritic hip conditions. PMID:27594336

  14. Skin conditions in figure skaters, ice-hockey players and speed skaters: part II - cold-induced, infectious and inflammatory dermatoses.

    PubMed

    Tlougan, Brook E; Mancini, Anthony J; Mandell, Jenny A; Cohen, David E; Sanchez, Miguel R

    2011-11-01

    Participation in ice-skating sports, particularly figure skating, ice hockey and speed skating, has increased in recent years. Competitive athletes in these sports experience a range of dermatological injuries related to mechanical factors: exposure to cold temperatures, infectious agents and inflammation. Part I of this two part review discussed the mechanical dermatoses affecting ice-skating athletes that result from friction, pressure, and chronic irritation related to athletic equipment and contact with surfaces. Here, in Part II, we review the cold-induced, infectious and inflammatory skin conditions observed in ice-skating athletes. Cold-induced dermatoses experienced by ice-skating athletes result from specific physiological effects of cold exposure on the skin. These conditions include physiological livedo reticularis, chilblains (pernio), Raynaud phenomenon, cold panniculitis, frostnip and frostbite. Frostbite, that is the literal freezing of tissue, occurs with specific symptoms that progress in a stepwise fashion, starting with frostnip. Treatment involves gradual forms of rewarming and the use of friction massages and pain medications as needed. Calcium channel blockers, including nifedipine, are the mainstay of pharmacological therapy for the major nonfreezing cold-induced dermatoses including chilblains and Raynaud phenomenon. Raynaud phenomenon, a vasculopathy involving recurrent vasospasm of the fingers and toes in response to cold, is especially common in figure skaters. Protective clothing and insulation, avoidance of smoking and vasoconstrictive medications, maintaining a dry environment around the skin, cold avoidance when possible as well as certain physical manoeuvres that promote vasodilation are useful preventative measures. Infectious conditions most often seen in ice-skating athletes include tinea pedis, onychomycosis, pitted keratolysis, warts and folliculitis. Awareness, prompt treatment and the use of preventative measures are

  15. The Incidence and Types of Physical Contact Associated with Body Checking Regulation Experience in 13–14 Year Old Ice Hockey Players

    PubMed Central

    Goulet, Claude; Roy, Thierry-Olivier; Nadeau, Luc; Hamel, Denis; Fortier, Kristine; Emery, Carolyn A.

    2016-01-01

    Background: Ice hockey has one of the highest sport participation and injury rates in youth in Canada. Body checking (BC) is the predominant mechanism of injury in leagues in which it is permitted. The objectives of this study were to determine whether the incidence and types of physical contact differ for Bantam players (aged 13–14 years) who were exposed to BC at Pee Wee level (aged 11–12 years) in Calgary, Alberta versus Bantam players who were not exposed to BC at Pee Wee level in Québec City, Québec. All teams were exposed to BC at bantam level; Methods: A cohort study was conducted in Québec City and Calgary. Sixteen games for Calgary and 15 for Québec City were randomly selected and analysed with a validated observation system to quantify five intensities of physical contact and to observe different types of physical contact such as slashing and holding; Results: A total of 5610 incidences of physical contact with the trunk and 3429 other types of physical contact were observed. Very light intensity trunk contact was more frequent in Calgary (adjusted incidence RR (ARR): 1.71; 95% CI: 1.28–2.29). Holding (ARR: 1.04; 95% CI: 1.02–1.07) and slashing (ARR: 1.38; 95% CI: 1.07–1.77) were more frequent in Calgary; Conclusion: Results suggest that players’ physical contacts differ between Bantam leagues in which BC was permitted at Pee Wee level and leagues in which it was not permitted until Bantam level. PMID:27399750

  16. PUCK: An Automated Prompting System for Smart Environments

    PubMed Central

    Das, Barnan; Cook, Diane J.; Schmitter-Edgecombe, Maureen; Seelye, Adriana M.

    2014-01-01

    The growth in popularity of smart environments has been quite steep in the last decade and so has the demand for smart health assistance systems. A smart home-based prompting system can enhance these technologies to deliver in-home interventions to users for timely reminders or brief instructions describing the way a task should be done for successful completion. This technology is in high demand given the desire of people who have physical or cognitive limitations to live independently in their homes. In this paper, with the introduction of the “PUCK” prompting system, we take an approach to automate prompting-based interventions without any predefined rule sets or user feedback. Unlike other approaches, we use simple off-the-shelf sensors and learn the timing for prompts based on real data that is collected with volunteer participants in our smart home test bed. The data mining approaches taken to solve this problem come with the challenge of an imbalanced class distribution that occurs naturally in the data. We propose a variant of an existing sampling technique, SMOTE, to deal with the class imbalance problem. To validate the approach, a comparative analysis with Cost Sensitive Learning is performed. PMID:25364323

  17. Campus Computing Looks Ahead: Tracking the Digital Puck.

    ERIC Educational Resources Information Center

    Green, Kenneth C.

    2002-01-01

    Examines data from the 2002 Campus Computing Survey to determine trends in information technology in higher education and future possibilities. Discusses Web portals; electronic commerce capabilities, including use of credit cards; budget challenges, including budget cuts; and mobile technology and wireless networks. (LRW)

  18. Myositis ossificans traumatica of the deltoid ligament in a 34 year old recreational ice hockey player with a 15 year post-trauma follow-up: a case report and review of the literature

    PubMed Central

    Muir, Brad

    2010-01-01

    Myositis ossificans traumatica is a relatively common injury associated with sports especially those involving contact. It continues to frustrate both athlete and health practitioner alike due to its continued lack of treatment options and a lengthy natural history. This case study chronicles the observation of a 34 year old recreational ice hockey player who presented 7 years post-trauma, was diagnosed with myositis ossificans traumatica and was followed up on 8 years later (15 years post-trauma). This case report is suspected to be the first published case study of its kind. The literature review outlines the various types of myositis ossificans, its incidence, pathogenesis, differential diagnoses including osteosarcoma, and the various methods/modalities reported in its treatment. PMID:21120014

  19. Particle-hole intruder levels in 67Cu, collectivity, monopole shifts, and the hockey-stick behaviour of ell - 1/2 5/2- levels in neutron-rich odd-mass Cu nuclei

    NASA Astrophysics Data System (ADS)

    Walters, W. B.; Chiara, C. J.

    2011-01-01

    A new sequence of gamma rays with energies of 572, 499, 585, and 674 keV has been identified in 67Cu populating the 7/2- level at 2362 keV. Owing to the strong population of the 2362-keV level via an ell = 3 proton pickup reaction, that level is assigned to be an f7/2-1 2-particle-1-hole "intruder" proton configuration, and the new levels are found to form a sequence consistent with intruder sequences in the adjacent odd-mass Cu isotopes and in the odd-mass Sb isotopes. The changing position of the intruder sequence in the odd-mass Cu isotopes is discussed and related to the onset of collectivity associated with the presence of g9/2 neutrons beyond N = 40. The increase in collectivity is also discussed for a number of isotonic and isotopic chains as more protons or neutrons, respectively, are added beyond an oscillator shell boundary. For most of these systems, the ell -1/2 levels show a systematic "hockey-stick-like" behaviour with a sharp decrease in energy with the addition of the first protons or neutrons, owing to both the added collectivity and the tensor interaction, and then a lower slope when collectivity changes are diminished and only the tensor interaction is influencing the changes in level positions.

  20. The 'Patient experience' revolution.

    PubMed

    Hooten, Doug; Zavadsky, Matt

    2014-02-01

    We're arguably at the most pivotal time in our young profession. The ACA has provided EMS an unprecedented opportunity to become a part of the healthcare system, a move that many of us have dreamed about for decades. We need to pay attention to the changing dynamics of the environment in which we operate. The factors that currently impact hospitals, doctors and other healthcare providers will also impact us sooner than we think. Take the time to help shape our future and how we participate in this new healthcare system. It's time to focus on the patient and the patient's experience with our service. Wayne Gretzky said two important things during an interview when he was asked what makes him such a great hockey player. One was, "You miss 100% of the shots you don't take." The other was, "A good hockey player plays where the puck is. A great hockey player plays where the puck is going to be. I skate to where the puck is going to be, not where it has been." Our advice to you is to go ahead, take the shot, get ahead of the other team and focus on improved customer satisfaction sooner rather than later. PMID:24660359

  1. The influence of impact object characteristics on impact force and force absorption by mouthguard material.

    PubMed

    Takeda, Tomotaka; Ishigami, Keiichi; Shintaro, Kawamura; Nakajima, Kazunori; Shimada, Atsushi; Regner, Connell Wayne

    2004-02-01

    Most impact force and impact energy absorption tests for mouthguards have used a steel ball in a drop-ball or the pendulum device. However, in reality most sports-related trauma is caused by objects other than the steel ball, e.g. various sized balls, hockey puck, or bat or stick. Also, the elasticity, the velocity and the mass of the object could change the degree and the extent of injuries. In this study, we attempted to measure the impact force from actual sports equipment in order to clarify the exact mechanism of dental-related sports injuries and the protective effects of mouthguards. The present study was conducted using the pendulum impact device and load cell. Impact objects were removable. Seven mobile impact objects were selected for testing: a steel ball, baseball, softball, field hockey ball, ice hockey puck, cricket ball, and wooden baseball bat. The mouthguard material used in this study was a 3-mm-thick Drufosoft (Dreve-Dentamid GmbH, Unna, Germany), and test samples were made of the one-layer type. The peak transmitted forces without mouthguard ranged from the smallest (ice hockey stick, 46.9 kgf) to the biggest (steel ball, 481.6 kgf). The peak transmitted forces were smaller when the mouthguard was attached than without it for all impact materials but the effect was significantly influenced by the object type. The steel ball showed the biggest (62.1%) absorption ability while the wooden bat showed the second biggest (38.3%). The other balls or the puck showed from 0.6 to 6.0% absorbency. These results show that it is important to test the effectiveness of mouthguards on specific types of sports equipment. In future, we may select different materials and mouthguard designs suitable for specific sports. PMID:14998410

  2. ReviewsGCSE Book Review: Modular Science for AQA GCSE Book Review: Modular Science for Edexcel GCSE Book Review: Revise for GCSE Science (Edexcel Modular Foundation and Higher) GCSE Book Review: AQA GCSE Physics, AQA GCSE Physics Additions Book Review: Studying Maths and its Applications Book Review: Medical Physics, 2nd edition Book Review: The Physics of Hockey Book Review: Nine Crazy Ideas In Science Book Review: Light and Dark Talking Point: The Skeptical Environmentalist Places To Visit: Centre for Alternative Technology, Machynlleth, Powys Resources: Sources of Energy Web Watch: Terence, this is stupid stuff...

    NASA Astrophysics Data System (ADS)

    2003-03-01

    GCSE BOOK REVIEWS (162) Modular Science for AQA Modular Science for Edexcel Revise for GCSE Science (Edexcel Modular Foundation and Higher) AQA GCSE Physics, AQA GCSE Physics Additions BOOK REVIEWS (166) Studying Maths and its Applications Medical Physics, 2nd edition The Physics of Hockey Nine Crazy Ideas In Science Light and Dark TALKING POINT (169) The Skeptical Environmentalist PLACES TO VISIT (170) Centre for Alternative Technology, Machynlleth, Powys RESOURCES (172) Sources of Energy WEB WATCH (173) Terence, this is stupid stuff...

  3. Metazoan meiofauna within the oxygen-minimum zone off Chile: Results of the 2001-PUCK expedition

    NASA Astrophysics Data System (ADS)

    Veit-Köhler, Gritta; Gerdes, Dieter; Quiroga, Eduardo; Hebbeln, Dierk; Sellanes, Javier

    2009-07-01

    A quantitative study of metazoan meiofauna was carried out at continental shelf and slope stations affected by the oxygen-minimum zone in the eastern South Pacific off Chile. Densities of meiobenthos at the investigated stations off Antofagasta (22°S), Concepción (36°S), and Chiloé (42°S) ranged from 1282.1 to 8847.8 ind 10 cm -2. Oxygen deficiency led only to average abundances, despite higher food availability and freshness at the corresponding sites. Sediment organic carbon, chlorophyll- a, and phaeopigment contents were used as measures of the input from water-column primary production, which accumulated at the oxygen-minimum zone stations. The highest abundances were found at a station with an oxygen content of 0.79 mL L -1, which was slightly elevated from what is defined as oxygen minimum (0.5 mL L -1). The most oxygenated site yielded the lowest densities. Meiofauna assemblages became more diverse with increasing bottom-water oxygenation, whereas nematodes were the most abundant taxon at every station, followed by annelids, copepods, and nauplii.

  4. Puck in the Schoolyard: Crassing the Bard at Hawthorn Secondary College.

    ERIC Educational Resources Information Center

    Hayes, Terry

    1999-01-01

    Claims doing "A Midsummer Night's Dream" as a school production allows students to bring their own personalities and cultures into the play. Explains how the production can be both inclusive, making room for many extra actions, as well communal, vivifying a school community to make it live more intensely. (NH)

  5. Ultra-Compact Motor Controller

    NASA Technical Reports Server (NTRS)

    Townsend, William T.; Cromwell, Adam; Hauptman, Traveler; Pratt, Gill Andrews

    2012-01-01

    This invention is an electronically commutated brushless motor contro ller that incorporates Hall-array sensing in a small, 42-gram packag e that provides 4096 absolute counts per motor revolution position s ensing. The unit is the size of a miniature hockey puck, and is a 44 -pin male connector that provides many I/O channels, including CANbus , RS-232 communications, general-purpose analog and digital I/O (GPI O), analog and digital Hall inputs, DC power input (18-90 VDC, 0-l0 A), three-phase motor outputs, and a strain gauge amplifier.

  6. Augmented Reality Comes to Physics

    NASA Astrophysics Data System (ADS)

    Buesing, Mark; Cook, Michael

    2013-04-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as Tagwhat and Star Chart (a must for astronomy class). The yellow line marking first downs in a televised football game2 and the enhanced puck that makes televised hockey easier to follow3 both use augmented reality to do the job.

  7. Video Gaming Promotes Concussion Knowledge Acquisition in Youth Hockey Players

    ERIC Educational Resources Information Center

    Goodman, David; Bradley, Nori L.; Paras, Bradley, Williamson, Ian J.; Bizzochi, James

    2006-01-01

    While the positive uses for video games in an educational setting have also been established, the educational aim is usually made explicit. The goal of this research was to develop a video game wherein the educational aspect was implicitly embedded in the video game, such that the gameing activity remained interesting and relevant. Following a…

  8. Reconstructions of paleoclimate: Beyond the hockey stick. (Invited)

    NASA Astrophysics Data System (ADS)

    Nychka, D. W.; Li, B.

    2010-12-01

    Our understanding of past climate before the instrumental record is based on a variety of indirect information gleaned from climate proxies. Some well studied proxies include tree ring width and density, lake sediments, pollen indices and temperatures from bore holes. Combining such observations and including physical constraints on the target climate processes is well suited to recent methods in Bayesian statistics and is in contrast to previous methods used for paleoclimate reconstruction. This talk gives an introduction to this new perspective. To reconstruct past temperatures a traditional approach views the proxies as imperfect "thermometers" and calibrates them with instrument observations during a period where both are present. With this calibration one uses the proxies to predict temperature in other periods. This direct approach has the disadvantage that is it difficult to quantify the uncertainty of the reconstruction and to account for proxies that respond to temperature at different temporal and spatial scales. In addition, when different subsets of proxies are available for different reconstruction periods it is problematic to produce a single consistent and continuous reconstruction. A Bayesian hierarchical method demands more assumptions on the target climate process but also produces a more consistent analysis that addresses these shortcomings. The basic idea is to divide the statistical model into three distinct levels: a data level where the proxy measurement is related to the climate process, a process level that asserts a statistical model for the climate process and finally a level that puts prior distributions on unknown statistical parameters. With these statistical models in place, the relationships are inverted using Bayes theorem to give a distribution of the climate process given the proxy data and instrumental record. In the past, this inversion has been difficult to carry out analytically but with more abundant computational resources these computations can now be done using Monte Carlo techniques (e.g. Markov Chain Monte Carlo). Although this hierarchy of statistical models may seem to require more assumptions some of these need to be tacitly assumed in more traditional approaches. Also, assumptions on the climate process can build in basic climate constraints, such as energy balances, that are both reasonable and can produce a more accurate reconstruction. As an example, a reconstruction for Northern Hemisphere annual temperatures will be presented. This reconstruction takes advantage of several forcing series (e.g CO2 concentrations) as covariates and also provides an ensemble of reconstructions to convey the uncertainty in the analysis. This framework is also suitable for reconstructions of spatial fields and of several climate variables, such as temperature and precipitation, simultaneously.

  9. Pilot study to test effectiveness of video game on reaching performance in stroke

    PubMed Central

    Acosta, Ana Maria; Dewald, Hendrik A.; Dewald, Jules P. A.

    2012-01-01

    Robotic systems currently used in upper-limb rehabilitation following stroke rely on some form of visual feedback as part of the intervention program. We evaluated the effect of a video game environment (air hockey) on reaching in stroke with various levels of arm support. We used the Arm Coordination Training 3D system to provide variable arm support and to control the hockey stick. We instructed seven subjects to reach to one of three targets covering the workspace of the impaired arm during the reaching task and to reach as far as possible while playing the video game. The results from this study showed that across subjects, support levels, and targets, the reaching distances achieved with the reaching task were greater than those covered with the video game. This held even after further restricting the mapped workspace of the arm to the area most affected by the flexion synergy (effectively forcing subjects to fight the synergy to reach the hockey puck). The results from this study highlight the importance of designing video games that include specific reaching targets in the workspace compromised by the expression of the flexion synergy. Such video games would also adapt the target location online as a subject’s success rate increases. PMID:21674392

  10. Pilot study to test effectiveness of video game on reaching performance in stroke.

    PubMed

    Acosta, Ana Maria; Dewald, Hendrik A; Dewald, Jules P A

    2011-01-01

    Robotic systems currently used in upper-limb rehabilitation following stroke rely on some form of visual feedback as part of the intervention program. We evaluated the effect of a video game environment (air hockey) on reaching in stroke with various levels of arm support. We used the Arm Coordination Training 3D system to provide variable arm support and to control the hockey stick. We instructed seven subjects to reach to one of three targets covering the workspace of the impaired arm during the reaching task and to reach as far as possible while playing the video game. The results from this study showed that across subjects, support levels, and targets, the reaching distances achieved with the reaching task were greater than those covered with the video game. This held even after further restricting the mapped workspace of the arm to the area most affected by the flexion synergy (effectively forcing subjects to fight the synergy to reach the hockey puck). The results from this study highlight the importance of designing video games that include specific reaching targets in the workspace compromised by the expression of the flexion synergy. Such video games would also adapt the target location online as a subject's success rate increases. PMID:21674392

  11. Experimental measurement and numerical simulation of residual stresses in a carburized layer of a 5120 steel

    SciTech Connect

    Rangaswamy, P.; Bourke, M.A.M.; Shipley, J.C.; Goldstone, J.A.

    1995-09-01

    A combined experimental and numerical study of residual stress and microstructure has been performed for a carburized steel 5120 specimen. Specimens were cut from 5120 steel bar stock, in the shape of hockey pucks and were subsequently carburized and quenched. X-ray diffraction was used to record stress profiles through the case for the martensite and retained austenite on the two flat surfaces oriented up and down during the quench. Layer removal was performed by electropolishing. Rietveld analysis was used to determine the lattice parameters of the phases at each depth varying with both carbon content and stress. The experimental measurements are compared with a numerical simulation of the phase transformation and the metallurgical changes following the carburization and quench. Results am discussed in the context of the microstructure and the role played by the retained austenite in interpretation. In addition the carbon profile obtained from the lattice parameters is compared with profiles measured using burnout.

  12. Insulin Delivery System

    NASA Technical Reports Server (NTRS)

    1988-01-01

    When Programmable Implantable Medication System (PIMS) is implanted in human body, it delivers precise programmed amounts of insulin over long periods of time. Mini-Med Technologies has been refining the Technologies since initial development at APL. The size of a hockey puck, and encased in titanium shell, PIMS holds about 2 1/2 teaspoons of insulin at a programmed basal rate. If a change in measured blood sugar level dictates a different dose, the patient can vary the amount of insulin delivered by holding a small radio transceiver over the implanted system and dialing in a specific program held in the PIMS computer memory. Insulin refills are accomplished approximately 4 times a year by hypodermic needle.

  13. Characteristics and Applications of a High Performance, Miniaturized, Infrasound Sensor

    NASA Astrophysics Data System (ADS)

    Rothman, J. L.; Marriott, D. A.

    2015-12-01

    Infrasound Sensors have been used for many years to monitor a large number of geophysical phenomena and manmade sources. Due to their large size and power consumption these sensors have typically been deployed in fixed arrays, portable arrays have required trucks to transport the sensors and support equipment. A high performance, miniaturized, infrasound microphone has been developed to enable mobile infrasound measurements that would otherwise be impractical. The new device is slightly larger than a hockey puck, weighs 200g, and consumes less than 150mW. The sensitivity is 0.4V/Pa and self noise at 1Hz is less than 0.63μPa²/Hz. The characteristics were verified using a calibrator tracable to the Los Alamos calibration chamber. Field tests have demonstrated the performance is comparable to a Chaparral model 25. Applications include man portable arrays, mobile installations, and UAV based measurements.

  14. Non-ideal detonation behaviour of PBX 9502

    NASA Astrophysics Data System (ADS)

    Schoch, Stefan; Nikiforakis, Nikos

    2009-06-01

    Numerical experiments are performed investigating the non-ideal detonation behaviour of PBX 9502 in two setups. In the first setup we consider a three-dimensional rate stick experiment. A booster charge initiates a reaction front leading to a curved detonation wave. The numerical results are compared to theory and experimental evidence. The effects of weak and strong confinement are discussed. The second setup considers the so called ``hockey puck experiment.'' Experimental results show the appearance of a dead zone due to the effect of the geometry. This is captured by the numerical results, which also reveal that the initially spherical detonation is diffracted leading to local detonation failure. The numerical simulations are performed by solving a mathematical model for a three-phase medium based on the Euler equations. The numerical results are obtained using high-resolution shock-capturing methods combined with adaptive mesh refinement.

  15. A resolution congratulating the University of Minnesota Duluth men's ice hockey team on winning their first National Collegiate Athletic Association (NCAA) Division I Men's Hockey National Championship.

    THOMAS, 112th Congress

    Sen. Klobuchar, Amy [D-MN

    2011-04-14

    05/04/2011 Resolution agreed to in Senate without amendment and with a preamble by Unanimous Consent. (text: CR S2695) (All Actions) Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

  16. A resolution congratulating the University of Minnesota women's ice hockey team on winning its second straight National Collegiate Athletic Association Women's Ice Hockey Championship.

    THOMAS, 113th Congress

    Sen. Klobuchar, Amy [D-MN

    2013-04-25

    04/25/2013 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (consideration: CR S3060; text as passed Senate: CR S3049) (All Actions) Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

  17. A resolution congratulating the Boston College men's ice hockey team on winning its fifth National Collegiate Athletic Association Division I Men's Hockey Championship.

    THOMAS, 112th Congress

    Sen. Kerry, John F. [D-MA

    2012-04-25

    04/25/2012 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (consideration: CR S2741-2742; text as passed Senate: CR S2742; text of measure as introduced: CR S2736) (All Actions) Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

  18. A resolution congratulating the Alaska Aces hockey team on winning the 2014 Kelly Cup as champions of the East Coast Hockey League.

    THOMAS, 113th Congress

    Sen. Begich, Mark [D-AK

    2014-06-12

    06/12/2014 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (consideration: CR S3673; text as passed Senate: CR S3671) (All Actions) Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

  19. Exploring Coaching Actions Based on Developed Values: A Case Study of a Female Hockey Coach

    ERIC Educational Resources Information Center

    Callary, Bettina; Werthner, Penny; Trudel, Pierre

    2013-01-01

    There are few empirical studies that demonstrate how values are developed and how they are linked to coaching actions. There can be a discrepancy between the statement of coaches' values and their actual coaching actions. In order to examine how coaching actions are influenced by values that are developed over a lifetime, the purpose of this…

  20. The Validity and Reliability of a Performance Assessment Procedure in Ice Hockey

    ERIC Educational Resources Information Center

    Nadeau, Luc; Richard, Jean-Francois; Godbout, Paul

    2008-01-01

    Background: Coaches and physical educators must obtain valid data relating to the contribution of each of their players in order to assess their level of performance in team sport competition. This information must also be collected and used in real game situations to be more valid. Developed initially for a physical education class context, the…

  1. An Examination of the Relative Age Effect in Developmental Girls' Hockey in Ontario

    ERIC Educational Resources Information Center

    Smith, Kristy L.; Weir, Patricia L.

    2013-01-01

    The relative age effect (RAE) suggests that athletes may be provided with greater opportunities for success depending on the position of their birthdate in a sport's selection year. While the effect has been well established in men's sports, less is known about women's sports. This study examined the RAE in developmental girls'…

  2. Hockey Gloves, Chocolate Bars, Asbestos, and Why Trees Fall in the Forest: Teaching Global Economics.

    ERIC Educational Resources Information Center

    Mackwood, Gae

    1991-01-01

    Discusses the need for global education in the face of economic influences that result in pollution and the exploitation of developing nations. Cites the difficulties faced by less developed countries that try to compete in world trade. Urges educators to teach students to take morally responsible positions on global relations. (SG)

  3. Protein carbonyl levels correlate with performance in elite field hockey players.

    PubMed

    Rosa-Lima, Frederico Luis; Lannes, Luiz; Viana-Gomes, Diego; Pierucci, Anna Paola T R; Salerno, Verônica P

    2015-07-01

    Excess and incorrectly selected exercise can degrade athletic performance from an imbalance in redox homeostasis and oxidative stress, but well-planned training and nutrition can improve antioxidant capacity. The aim of the study was to investigate how nutrient intake could influence oxidative stress and cell lesion biomarkers after 5 days of training followed by a game. Blood was collected from 10 athletes at the start of training (basal), after training (pre-game), and postgame. Their acceleration capacity also was measured pre- and postgame. Blood analysis showed an increase in lactate concentration postgame (13%) and total antioxidant capacity increased both pre-game (13.1%) and postgame (12.7%), all in comparison with basal levels. An oxidative stress marker, protein carbonyl (PC), increased 3-fold over the course of the game, which correlated with a decreased acceleration (r = 0.749). For biomarkers of tissue damage, creatine kinase and aspartate transaminase (AST) increased postgame by 150% and 75%, respectively. The AST variation had a high negative correlation with energy and carbohydrate consumption and a moderate correlation with lipid and vitamin C intake. Protein intake had a positive but moderate correlation with reduced glutathione. The observed correlations suggest that nutritional monitoring can improve exercise physiological homeostasis and that PC serves as a good biomarker for oxidative stress and performance loss. PMID:25962716

  4. Coach Selections and the Relative Age Effect in Male Youth Ice Hockey

    ERIC Educational Resources Information Center

    Hancock, David J.; Ste-Marie, Diane M.; Young, Bradley W.

    2013-01-01

    Relative age effects (RAEs; when relatively older children possess participation and performance advantages over relatively younger children) are frequent in male team sports. One possible explanation is that coaches select players based on physical attributes, which are more likely witnessed in relatively older athletes. Purpose: To determine if…

  5. The uncertain hockey stick: a statistical perspective on the reconstruction of past temperatures

    NASA Astrophysics Data System (ADS)

    Nychka, D.; Li, B.

    2006-12-01

    Temperature reconstructions based on proxies is inherently a statistical process and a deliberate statistical model for the reconstruction can also provide companion measures of uncertainty. Although statistical error is acknowledged to be just one component of the total uncertainty in a reconstruction, it can provide a valuable yardstick for comparing different reconstructions or drawing inferences about features. In this talk we suggest a framework where the reconstruction is expressed as a conditional distribution of the temperatures given the proxies. Random draws from this distribution provide an ensemble of reconstructions where the spread among ensemble members is a valid statistical measure of uncertainty. This approach is illustrated for Northern Hemisphere temperatures and the multi-proxy data used by Mann, Bradley and Hughes (1999). Here we explore the scope of the statistical assumptions needed to carry through a rigorous analysis and use Monte Carlo sampling to determine the uncertainty in maxima or other complicated statistics in the reconstructed series. The principles behind this basic example for the Northern Hemisphere can be extended to regional reconstructions (e.g. climate field reconstructions),incorporation of additional types proxies and the use of statistics from numerical models.

  6. The uncertain hockey stick: a statistical perspective on the reconstruction of past temperatures

    NASA Astrophysics Data System (ADS)

    Nychka, Douglas

    2007-03-01

    A reconstruction of past temperatures based on proxies is inherently a statistical process and a deliberate statistical model for the reconstruction can also provide companion measures of uncertainty. This view is often missed in the heat of debating the merits of different analyses and interpretations of paleoclimate data. Although statistical error is acknowledged to be just one component of the total uncertainty in a reconstruction, it can provide a valuable yardstick for comparing different reconstructions or drawing inferences about features. In this talk we suggest a framework where the reconstruction is expressed as a conditional distribution of the temperatures given the proxies. Random draws from this distribution provide an ensemble of reconstructions where the spread among ensemble members is a valid statistical measure of uncertainty. This approach is illustrated for Northern Hemisphere temperatures and the multi-proxy data used by Mann, Bradley and Hughes (1999). Here we explore the scope of the statistical assumptions needed to carry through a rigorous analysis and use Monte Carlo sampling to determine the uncertainty in maxima or other complicated statistics in the reconstructed series. The principles behind this simple example for the Northern Hemisphere can be extended to regional reconstructions, incorporation of additional types proxies and the use of statistics from numerical models.

  7. The `hockey stick' and the 1990s: a statistical perspective on reconstructing hemispheric temperatures

    NASA Astrophysics Data System (ADS)

    Li, Bo; Nychka, Douglas W.; Ammann, Caspar M.

    2007-10-01

    The short instrumental record of about 100-150 yr forces us to use proxy indicators to study climate over long timescales. The climate information in these indirect data is embedded in considerable noise, and the past temperature reconstructions are therefore full of uncertainty, which blurs the understanding of the temperature evolution. To date, the characterization and quantification of uncertainty have not been a high priority in reconstruction procedures. Here we propose a new statistical methodology to explicitly account for three types of uncertainties in the reconstruction process. Via ensemble reconstruction, we directly obtain the distribution of decadal maximum as well as annual maximum. Our method is an integration of linear regression, bootstrapping and cross-validation techniques, and it (1) accounts for the effects of temporal correlation of temperature; (2) identifies the variability of the estimated statistical model and (3) adjusts the effects of potential overfitting. We apply our method to the Northern Hemisphere (NH) average temperature reconstruction. Our results indicate that the recent decadal temperature increase is rapidly overwhelming previous maxima, even with uncertainty taken into account, and the last decade is highly likely to be the warmest in the last millennium.

  8. An Experimental Investigation of Detonation Corner-Turning Using High Resolution Radiography

    SciTech Connect

    Molitoris, J D; Andreski, H G; Garza, R G; Batteux, J D; Souers, P C

    2006-07-19

    We have performed experiments investigating detonation corner turning over a range of high-explosives including LX-17, Composition B, LX-04 and Tritonal. The primary diagnostic utilized here was a new high-resolution x-ray system that was capable of recording a time sequence of the detonation process as it negotiated the corner of interest and propagated. For LX-17 our data detail the formation of a significant dead-zone. Although the detonation eventually turned the corner in LX-17, the dead zone persisted to late times and evidence exists that it never was consumed by either detonation or fast combustion processes. In LX-17 the detonations ability to corner-turn increases as the density is reduced. Furthermore, lowering the density decreases the size of the dead-zone and alters its shape. The other high-explosives investigated were able to turn the corner immediately with no indication of any dead-zone formation.

  9. Haptic guidance of overt visual attention

    PubMed Central

    List, Alexandra; Iordanescu, Lucica; Grabowecky, Marcia; Suzuki, Satoru

    2014-01-01

    Research has shown that information accessed from one sensory modality can influence perceptual and attentional processes in another modality. Here, we demonstrated a novel crossmodal influence of haptic-shape information on visual attention. Participants visually searched for a target object (e.g., an orange) presented among distractor objects, fixating the target as quickly as possible. While searching for the target, participants held (never viewed and out of sight) an item of a specific shape in their hands. In two experiments, we demonstrated that the time for the eyes to reach a target—a measure of overt visual attention—was reduced when the shape of the held item (e.g., a sphere) was consistent with the shape of the visual target (e.g., an orange), relative to when the held shape was unrelated to the target (e.g., a hockey puck) or when no shape was held. This haptic-to-visual facilitation occurred despite the fact that the held shapes were not predictive of the visual targets’ shapes, suggesting that the crossmodal influence occurred automatically, reflecting shape-specific haptic guidance of overt visual attention. PMID:24935805

  10. The Winter Olympics in Lillehammer: the last dress rehearsal for Atlanta '96.

    PubMed

    Cantwell, J D

    1994-06-01

    Buoyed by the Norwegian spirit and example, our Atlanta Olympic medical team returned with a sense of admiration and also with the self-confidence that we can provide the same quality of medical care in 1996. It won't be an easy task, though, as the summer games are at least eight times the size of the winter games. It will take great cooperation and self-sacrifice from area physicians and hospitals that are now seemingly enmeshed in vigorous competition for the health care dollar. Perhaps, like Bjornson, I am also an idealist. But I truly feel that we can rise to the occasion and cooperate fully in unselfish ways to accomplish what needs to be done. We will then be able to look back upon the experience with a great sense of self-satisfaction, not for personal accolades, but for a job well done. In 1996, we can show the world the remarkable and too often maligned American health care system and, in so doing, make friends with people from all over the globe. "Let our deeds speak for themselves," implored Bjornson. I toasted that thought with a second glass of Chateau Batailley, then took a long nap and dreamed that I had slapped the hockey puck past the Russian goalie in double overtime to bring a gold medal back to the good old U.S. of A. PMID:8071635