Severe tracheal tear - an alternative extracorporeal membrane oxygenation indication.

INTRODUCTION: Conservative management is usually preferred for iatrogenic tracheal injuries. Venovenous extracorporeal membrane oxygenation (V-V ECMO) is mostly used in acute refractory hypoxemia, airway lesions are an alternative indication. CASE REPORT: A 51-year-old female was transferred with a large tracheal tear after plastic tracheotomy. Due to a critical ventilation situation with hypercapnia, conservative management was set and V-V ECMO was installed. With optimized tube positioning, minimal ventilation and gas transfer via V-V ECMO, a complete healing of the injury could be achieved. DISCUSSION: Fast diagnosis of tracheal injuries is essential; transfer to a specialized centre should be considered. In our case, organ support via ECMO was necessary due to a difficult ventilation situation with persisting hypercapnia. Thus, reduction in ventilation pressures with reduction of possible leakage and healing of the tracheal tear could be achieved. CONCLUSION: Management of tracheal tears is complex; in severe cases special therapy concepts such as the use of V-V ECMO may become necessary.

Comparative analysis of a geometric and an adhesive righting strategy against toppling in inclined hexapedal locomotion.

Animals are known to exhibit different walking behaviors in hilly habitats. For instance, cats, rats, squirrels, tree frogs, desert iguana, stick insects and desert ants were observed to lower their body height when traversing slopes, whereas mound-dwelling iguanas and wood ants tend to maintain constant walking kinematics regardless of the slope. This paper aims to understand and classify these distinct behaviors into two different strategies against toppling for climbing animals by looking into two factors: (i) the torque of the center of gravity (CoG) with respect to the critical tipping axis, and (ii) the torque of the legs, which has the potential to counterbalance the CoG torque. Our comparative locomotion analysis on level locomotion and inclined locomotion exhibited that primarily only one of the proposed two strategies was chosen for each of our sample species, despite the fact that a combined strategy could have reduced the animal's risk of toppling over even more. We found that Cataglyphis desert ants (species Cataglyphis fortis) maintained their upright posture primarily through the adjustment of their CoG torque (geometric strategy), and Formica wood ants (species Formica rufa), controlled their posture primarily by exerting leg torques (adhesive strategy). We further provide hints that the geometric strategy employed by Cataglyphis could increase the risk of slipping on slopes as the leg-impulse substrate angle of Cataglyphis hindlegs was lower than that of Formica hindlegs. In contrast, the adhesion strategy employed by Formica front legs not only decreased the risk of toppling but also explained the steeper leg-impulse substrate angle of Formica hindlegs which should relate to more bending of the tarsal structures and therefore to more microscopic contact points, potentially reducing the risk of hindleg slipping.

Physical Match Performance in Sub-elite Soccer Players - Introduction of a new Index.

This investigation examined the position-specific physical performance in different locomotor categories and physiological demands concurrently in official games of sub-elite players and to present a new performance index (PI). Time-motion (distance, velocity, acceleration) and heart rate data of 55 soccer players were simultaneously captured via a GPS tracking system. The relationship between external and internal match-load (PI) was determined on the basis of heart rate, average velocity and acceleration. In contrast to the mean heart rate (85.2±3.2%, P=0.806, ηp²=0.03), the average total distance covered (9946±715 m) was largely affected by players' position (P<0.001, ηp²=0.63). Furthermore, a mixed design ANOVA showed a large interaction effect between position and locomotor category (P<0.001, ηp²=0.44). On average, PI was 1.57±0.37 m/min²/%, with notably lower values in the 2nd half. The position-specific profiles already reported for higher leagues were also present in sub-elite soccer players. Despite lower values for total distance and smaller distances in the high-intensity zones (>14.4 km/h), internal loads were comparable to those observed in European top leagues. In comparison to a performance measure that ignores accelerations, PI was shown to be less dependent on the playing position and had higher variability. Consequently, PI is better suited to distinguish between players' performance.

Does low back pain affect the reliability of postural regulation?

The aim of this study was to examine the intraobserver reliability of a posturographic assessment in patients with low back pain. We investigated 24 symptomatic subjects with defined low back pain (mean: 57.9 years) and a pair-matched control group including 24 asymptomatic persons (mean: 58.1 years). Each participant underwent two measurements on a posturographic device (32 Hz sampling rate) based on the Interactive Balance System (time interval: 7 d). Test procedure consisted of tests on solid ground with eyes open (1) and eyes closed (2). Data analysis included parameters of motor output and a frequency band analysis. Reliability tests were realized using by intraclass correlations (ICC). Coefficients of ICC ranged from 0.36 (95% CI: 0.01-0.73) to 0.94 (95% CI: 0.86-0.97) in both test positions. For 69% (11/16) of the investigated parameters a high level (ICC > 0.75) of intraobserver reliability was reached. Based on the results, the posturographic measurement system used in this study seems to be appropriate for use in longitudinal study designs in an orthopaedic setting.

Propulsion in hexapod locomotion: how do desert ants traverse slopes?

The employment of an alternating tripod gait to traverse uneven terrains is a common characteristic shared among many Hexapoda. Because this could be one specific cause for their ecological success, we examined the alternating tripod gait of the desert ant Cataglyphis fortis together with their ground reaction forces and weight-specific leg impulses for level locomotion and on moderate (±30 deg) and steep (±60 deg) slopes in order to understand mechanical functions of individual legs during inclined locomotion. There were three main findings from the experimental data. (1) The hind legs acted as the main brake (negative weight-specific impulse in the direction of progression) on both the moderate and steep downslopes while the front legs became the main motor (positive weight-specific impulse in the direction of progression) on the steep upslope. In both cases, the primary motor or brake was found to be above the centre of mass. (2) Normalised double support durations were prolonged on steep slopes, which could enhance the effect of lateral shear loading between left and right legs with the presence of direction-dependent attachment structures. (3) The notable directional change in the lateral ground reaction forces between the moderate and steep slopes implied the utilisation of different coordination programs in the extensor-flexor system.

Intermuscular pressure between synergistic muscles correlates with muscle force.

The purpose of the study was to examine the relationship between muscle force generated during isometric contractions (i.e. at a constant muscle-tendon unit length) and the intermuscular (between adjacent muscles) pressure in synergistic muscles. Therefore, the pressure at the contact area of the gastrocnemius and plantaris muscle was measured synchronously to the force of the whole calf musculature in the rabbit species Oryctolagus cuniculus Similar results were obtained when using a conductive pressure sensor, or a fibre-optic pressure transducer connected to a water-filled balloon. Both methods revealed a strong linear relationship between force and pressure in the ascending limb of the force-length relationship. The shape of the measured force-time and pressure-time traces was almost identical for each contraction (r=0.97). Intermuscular pressure ranged between 100 and 700 mbar (70,000 Pa) for forces up to 287 N. These pressures are similar to previous (intramuscular) recordings within skeletal muscles of different vertebrate species. Furthermore, our results suggest that the rise in intermuscular pressure during contraction may reduce the force production in muscle packages (compartments).

Ultra-miniature force plate for measuring triaxial forces in the micronewton range.

Measuring the ground reaction forces of a single leg is indispensable to understanding the dynamics of legged locomotion. Because of the technical state of the art, investigations are limited to animals with a body mass above 1 g. Here we present the design, fabrication, calibration and performance of a novel ultra-miniature force platform at the micronewton level. The sensor was built using the stereolithography technology and is equipped with semiconductor strain gauges. We found a highly linear signal response in the calibrated force range to ±1300 µN. Individual tests revealed that our force plate still shows a linear response at forces as great as 4 mN, confirming a large measuring range and particular robustness. The sensitivity was above 50 V N(-1) in all directions, which makes it possible to resolve forces of 10 µN. We demonstrated the suitability of the device on the basis of a typical ground reaction force measurement of an ant, Formica polyctena.

Level locomotion in wood ants: evidence for grounded running.

In order to better understand the strategies of locomotion in small insects, we have studied continuous level locomotion of the wood ant species Formica polyctena. We determined the three-dimensional centre of mass kinematics during the gait cycle and recorded the ground reaction forces of single legs utilising a self-developed test site. Our findings show that the animals used the same gait dynamics across a wide speed range without dissolving the tripodal stride pattern. To achieve higher velocities, the ants proportionally increased stride length and stepping frequency. The centre of mass energetics indicated a bouncing gait, in which horizontal kinetic and gravitational potential energy fluctuated in close phase. We determined a high degree of compliance especially in the front legs, as the effective leg length was nearly halved during the contact phase. This leads to only small vertical oscillations of the body, which are important in maintaining ground contact. Bouncing gaits without aerial phases seem to be a common strategy in small runners and can be sufficiently described by the bipedal spring-loaded inverted pendulum model. Thus, with our results, we provide evidence that wood ants perform 'grounded running'.

Erythropoietin rs1617640 G allele associates with an attenuated rise of serum erythropoietin and a marked decline of hemoglobin in hepatitis C patients undergoing antiviral therapy.

BACKGROUND: A decline in hemoglobin (Hb) concentration during antiviral therapy in chronic hepatitis C (CHC) is a serious side effect. It may compel to dose reduction or even termination of antiviral treatment. The activation of erythropoietin (EPO) synthesis as a physiological response to anemia and its relation to a genetic variation within the EPO gene has not been evaluated yet. METHODS: Data of 348 CHC patients were reviewed retrospectively. Samples were genotyped for EPO rs1617640 and inosine triphosphatase (ITPA) rs1127354. Serum EPO concentrations were determined before and during therapy. Primary endpoints were set as Hb decline >3 g/dl at weeks 4 and 12. RESULTS: EPO rs1617640 G homozygotes showed a significantly lower rise of serum EPO level over time than T allele carriers (p < 0.001). The cumulative frequency of a significant Hb reduction added up to 40%. Multivariate analysis revealed that besides age, ribavirin starting dose and baseline Hb also EPO rs1617640 G homozygosity associates with Hb reduction at week 4 (p = 0.025) and 12 (p = 0.029), while ITPA C homozygotes are at risk for Hb decline particularly early during treatment. Furthermore, EPO rs1617640 G homozygotes were more frequently in need for blood transfusion, epoetin-α supplementation, or ribavirin dose reduction (p < 0.001). CONCLUSIONS: Our data suggest that EPO rs1617640 genotype, the rise of serum EPO concentration as well as ITPA rs1127354 genotype are promising parameters to evaluate the Hb decline during antiviral therapy. A rational adjustment of therapy with epoetin-α supplementation might prevent serious adverse events or the need to terminate treatment.

Accuracy of unilateral and bilateral gait assessment using a mobile gait analysis system at different walking speeds.

BACKGROUND: Previous research on the accuracy of mobile measurement systems has focused on parameters related to the whole gait cycle. Specifically, bilateral gait characteristics were primarily used as outcome measures. RESEARCH QUESTION: How accurate are unilateral gait characteristics detected using a mobile system at various fixed walking speeds? METHODS: Gait analysis during treadmill walking at velocities (VEL) of 2.5 (v1), 4.5 (v2) and 6.5 km/h (v3) was performed in a population of 47 healthy young adults, consisting of 27 females (age: 23 ± 2 years, BMI: 21.4 ± 2.2 kg/m²) and 20 males (age: 22 ± 1 years, BMI: 23.3 ± 3.4 kg/m²). Spatiotemporal gait data were simultaneously determined using an instrumented treadmill (gaitway 3D) and a mobile gait analysis system (RehaGait). Besides VEL, bilateral (stride length [SL], cadence [CAD]) and unilateral (contact duration [CON], single [SS] and double support duration [DS]) outcomes were validated. RESULTS: Across the three VEL investigated, the correlations between both measurement systems were almost perfect in SL and CAD (r > 0.97). In addition, SL significantly differed (p < 0.01) with moderate to large effects, whereby the root mean squared error (RMSE) did not exceed 1.8 cm. RMSE in CAD was not higher than 0.33 spm and statistically significant differences were only present at v1 (d = 0.63). DS was the most erroneous unilateral parameter with values for %RMSE ranging from 9% at v1 to 14% at v3. In CON and SS %RMSE was in a magnitude of 2-4% across all VEL. Furthermore, VEL affected measurement accuracy in unilateral outcomes with moderate to large effects (F (2, 45) > 6.0, p < 0.01, ηp2 > 0.11) with consistently higher differences at lower velocities. SIGNIFICANCE: Based on the results presented the validity of the mobile gait analysis system investigated to detect gait asymmetries must be questioned.

Alberta Stroke Program Early CT Scale evaluation of multimodal computed tomography in predicting clinical outcomes of stroke patients treated with aspiration thrombectomy.

BACKGROUND AND PURPOSE: Patient selection is crucial in the endovascular treatment of acute ischemic stroke patients. Baseline computed tomographic (CT) images, evaluated with the Alberta Stroke Program Early CT Scale (ASPECTS), are considered significant predictors of outcome. In this study, we evaluated CT images and perfusion parameters, analyzed with ASPECTS, as final outcome predictors after endovascular stroke treatment. METHODS: We analyzed a cohort of patients with acute ischemic stroke and endovascular treatment. Patients with an occlusion of the M1 segment and multimodal CT imaging were included. CT perfusion data were reconstructed using commercial software. Two experienced neuroradiologists separately reviewed and scored CT and CT perfusion images with the ASPECTS score. Parameters were compared between patients with poor and with favorable follow-up outcome. Significantly different variables were further analyzed by forward stepwise logistic regression. RESULTS: Fifty-one patients were included in our study. Baseline characteristics did not differ between patients with favorable and poor outcomes. No significant difference in recanalization status, the various times, or CT ASPECTS was demonstrated between these 2 groups. Significant differences were demonstrated for age (P=0.0049), cerebral blood volume ASPECTS (P=0.0007), and between cerebral blood volume and cerebral blood flow ASPECTS (P=0.0045). Cerebral blood volume ASPECTS>7 demonstrated the highest sensitivity and specificity for favorable outcome with 84% and 79%, respectively. CONCLUSIONS: CT perfusion parameters, evaluated with ASPECTS, are optimal predictors of outcome and are more sensitive and specific than CT ASPECTS in the prediction of favorable outcome. Use of these parameters in treatment decisions could reduce futile recanalizations.

Analyzability of Photoplethysmographic Smartwatch Data by the Preventicus Heartbeats Algorithm During Everyday Life: Feasibility Study.

BACKGROUND: Continuous heart rate monitoring via mobile health technologies based on photoplethysmography (PPG) has great potential for the early detection of sustained cardiac arrhythmias such as atrial fibrillation. However, PPG measurements are impaired by motion artifacts. OBJECTIVE: The aim of this investigation was to evaluate the analyzability of smartwatch-derived PPG data during everyday life and to determine the relationship between the analyzability of the data and the activity level of the participant. METHODS: A total of 41 (19 female and 22 male) adults in good cardiovascular health (aged 19-79 years) continuously wore a smartwatch equipped with a PPG sensor and a 3D accelerometer (Cardio Watch 287, Corsano Health BV) for a period of 24 hours that represented their individual daily routine. For each participant, smartwatch data were analyzed on a 1-minute basis by an algorithm designed for heart rhythm analysis (Preventicus Heartbeats, Preventicus GmbH). As outcomes, the percentage of analyzable data (PAD) and the mean acceleration (ACC) were calculated. To map changes of the ACC and PAD over the course of one day, the 24-hour period was divided into 8 subintervals comprising 3 hours each. RESULTS: Univariate analysis of variance showed a large effect (ηp2> 0.6; P<.001) of time interval (phase) on the ACC and PAD. The PAD ranged between 34% and 100%, with an average of 71.5% for the whole day, which is equivalent to a period of 17.2 hours. Between midnight and 6 AM, the mean values were the highest for the PAD (>94%) and the lowest for the ACC (<6×10-3 m/s2). Regardless of the time of the day, the correlation between the PAD and ACC was strong (r=-0.64). A linear regression analysis for the averaged data resulted in an almost perfect coefficient of determination (r2=0.99). CONCLUSIONS: This study showed a large relationship between the activity level and the analyzability of smartwatch-derived PPG data. Given the high yield of analyzable data during the nighttime, continuous arrhythmia screening seems particularly effective during sleep phases.

An Investigation into the Relationship Between Heart Rate Recovery in Small-Sided Games and Endurance Performance in Male, Semi-professional Soccer Players.

BACKGROUND: The ability to recover in the shortest possible time plays an important role especially in intermittent sports such as soccer. Evidence suggests that a well-developed endurance performance has positive effects on the repeated-sprint ability and thus also on the short-term recovery. However, it has not been clarified whether these relationships still exist in a soccer-specific situation. Therefore, the purpose of this investigation was to evaluate the ability of semi-professional soccer players to recover during standardized small-sided games (SSGs) as an endurance performance indicator. METHODS: Eighteen male semi-professional soccer players (age, 23.5 ± 3.7 years) performed an incremental treadmill test (ITT) to determine their running velocity and heart rate at a fixed lactate threshold of 4 mmol L-1 (v4). Two days later, the players carried out six bouts of 4 vs. 4 SSGs (duration, 90 s; load to rest ratio, 1:1). A GPS-based tracking system was used to determine distances covered at four fixed speed zones (i.e., < 7.2 km/h, 7.2-14.4 km/h, 14.4-19.8 km/h, > 19.8 km/h) and total distance covered during the SSGs. Furthermore, the frequency of occurrence of accelerations (> 1.54 m s-2) was calculated. SSGs' internal load was quantified by average heart rate and blood lactate concentration after the SSGs. Their recovery ability was evaluated using heart rate recovery (HRR) after the last bout of the SSGs. RESULTS: A very large correlation (r = - .91) with an explained variance of 84% was found between HRR and v4. Further, a better performance in the ITT was also related with a higher number of accelerations executed during SSGs (r = .60). The total distance and distances in predefined speed zones did not show any association to v4. CONCLUSIONS: This study showed a strong relationship between HRR after standardized 4 vs. 4 SSGs and the soccer players' endurance performance in a laboratory setting. Thus, besides being associated with endurance capacity, v4 seems sufficient to evaluate the sport-specific ability to recover in soccer players.

Absence of auto-antibodies against cardiac troponin I predicts improvement of left ventricular function after acute myocardial infarction.

AIMS: Application of antibodies against cardiac troponin I (cTnI-Ab) can induce dilation and dysfunction of the heart in mice. Recently, we demonstrated that immunization with cTnI induces inflammation and fibrosis in myocardium of mice. Others have shown that auto-antibodies to cTnI are present in patients with acute coronary syndrome, but little is known about the clinical relevance of detected cTnI-Ab. METHODS AND RESULTS: First, anti-cTnI and anti-cTnT antibody titres were measured in sera from 272 patients with dilated- (DCM) and 185 with ischaemic- (ICM) cardiomyopathy. Secondly, 108 patients with acute myocardial infarction (AMI) were included for a follow-up study. Heart characteristics were determined by magnetic resonance imaging 4 days and 6-9 months after AMI. Altogether in 7.0% of patients with DCM and in 9.2% with ICM, an anti-cTnI IgG antibody titre >/=1:160 was measured. In contrast, only in 1.7% of patients with DCM and in 0.5% with ICM, an anti-cTnT IgG antibody titre >/=1:160 was detected. Ten out of 108 patients included in the follow-up study were tested positive for cTnI-Ab with IgG Ab titres >/=1:160. TnI-Ab negative patients showed a significant increase in left ventricular ejection fraction (LVEF) and stroke volume 6-9 months after AMI. In contrast, there was no significant increase in LVEF and stroke volume in TnI-Ab positive patients. CONCLUSION: We demonstrate for the first time that the prevalence of cTnI-Abs in patients with AMI has an impact on the improvement of the LVEF over a study period of 6-9 months.

Enhanced sprint performance analysis in soccer: New insights from a GPS-based tracking system.

The aim of this investigation was to establish the validity of a GPS-based tracking system (Polar Team Pro System, PTPS) for estimating sprint performance and to evaluate additional diagnostic indices derived from the temporal course of the movement velocity. Thirty-four male soccer players (20 ± 4 years) performed a 20 m sprint test measured by timing gates (TG), and while wearing the PTPS. To evaluate the relevance of additional velocity-based parameters to discriminate between faster and slower athletes, the median-split method was applied to the 20-m times. Practical relevance was estimated using standardized mean differences (d) between the subgroups. Differences between the criterion reference (TG) and PTPS for the 10 and 20 m splits did not vary from zero (dt10: -0.01 ± 0.07 s, P = 0.7, d < -0.1; dt20: -0.01 ± 0.08 s, P = 0.4, d < -0.2). Although subgroups revealed large differences in their sprint times (d = -2.5), the average accelerations between 5 and 20 km/h as well as 20 and 25 km/h showed merely small effects (d < 0.5). Consequently, analyses of velocity curves derived from PTPS may help to clarify the occurrence of performance in outdoor sports. Thus, training consequences can be drawn which contribute to the differentiation and individualization of sprint training.

Differences in Player Position Running Velocity at Lactate Thresholds Among Male Professional German Soccer Players.

This study investigated the differences in running velocities at specific lactate thresholds among male German soccer players. One hundred fifty-two professional (3rd league: n = 78; 4th league: n = 74) male soccer players (mean ± SD; age: 24.7 ± 4.37 years, body mass: 80.8 ± 7.33 kg, body height: 1.83 ± 0.06 m) volunteered for the investigation. Players were categorized as goalkeepers, central defenders, central midfielders, wings and forward. Players completed a treadmill test, at incremental speeds, to determine running velocity at different blood lactate concentrations (v2 = 2 mmol/l; v4 = 4 mmol/l; and v6 = 6 mmol/l). In addition, the largest difference between positions for running velocity was found at the lactate threshold v2 (p = 0.005). The running data revealed that only goalkeepers had significantly lower velocities at the lactate thresholds compared to outfield players. The central midfielders showed the highest average performance level at the lactate thresholds (v2: 12.5 ± 1.20 km/h; v4: 15.2 ± 1.14 km/h; and v6: 16.6 ± 1.14 km/h). In conclusion, this study provides soccer and position-specific reference data for the running performance of male professional German soccer players to evaluate the endurance performance in a standardized way. In this context, future research should extend the database for the first and second leagues. Further research assessing running performance during competition matches over the entire season is required to validate the endurance test performance data.

Comparison of posturographic outcomes between two different devices.

The Interactive Balance System (IBS), a posturography device for assessing posture control, is widely used in clinical and rehabilitation settings. However, data on the validity of the device are unavailable. Fluctuations of the center of pressure (COP) were measured in 24 healthy participants (age: 29 ±â€¯5 (mean ±â€¯SD) years, 12 females) synchronously using the IBS, which was rigidly mounted on a Kistler platform. Four different bipedal conditions were examined: eyes open or closed on stable or soft surfaces. Time series were compared using congruity (CON, proportion of the measurement time during which values of both devices changed similarly in direction), whereas IBS-specific postural outcomes were correlated with traditional postural control outcomes of the Kistler force platform. The time-displacement curves showed similar shapes for CON (>0.9) for each of the four standing conditions without differences between male and female participants (P > 0.39). The path length results of both devices showed very high linear associations, explaining on average 92% (medio-lateral) or 96% (anterior-posterior) of the common variance. The Kistler path length of the anterior-posterior direction revealed nearly perfect linear associations with the stability index of the IBS (r2 > 0.99). The results of this study indicate that the IBS provides valid posturographic results. Since the medial-lateral and anterior-posterior trajectories of the IBS can be used to calculate COP fluctuations, comparisons between different measurement systems are possible.

Pantoprazole Does not Affect Serum Trough Levels of Tacrolimus and Everolimus in Liver Transplant Recipients.

Background: Liver transplant recipients are frequently treated with proton pump inhibitors. Drug interactions have been described especially with respect to omeprazole. Due to the lower binding capacity of pantoprazole to CYP2C19 this drug became preferred and became the most used proton pump inhibitor in Germany. The data on the influence of pantoprazole on immunosuppressive drugs in liver transplant recipients a very scarce. Methods: The authors performed a single center analysis in liver transplant recipients on the effect of pantoprazole on the serum trough levels of different immunosuppressants. The trough levels were compared over a period of 1 year before and after start or stop of a continuous oral co-administration of 40 mg pantoprazole once daily. Results: The serum trough levels of tacrolimus (n = 30), everolimus (n = 7), or sirolimus (n = 3) remain constant during an observation period of at least 1 year before and after co-administration of pantoprazole. None of the included patients needed a change of dosage of the observed immunosuppressants during the observation period. Conclusions: The oral co-administration of pantoprazole is safe in immunosuppressed liver transplant recipients according to the serum trough levels of tacrolimus, everolimus, and sirolimus. This analysis provides first data on the influence of pantoprazole on immunosuppressive drugs in liver transplant recipients.

Reliability of an ice hockey-specific complex test.

BACKGROUND: This study assessed the intra-rater reliability of an ice hockey-specific complex test (IHCT) that reflects the intense multidirectional and intermittent efforts required in ice hockey. METHODS: Twenty professional players executed the IHCT twice over an interval of 2 days. Load parameters included a 10-m sprint, a 30-m transition with and without a puck, as well as slap and wrist shots. Stress parameters were lactate concentrations and heart rates. RESULTS: The intrarater reliability (ICC) ranged from 0.54 to 0.98 for load parameters, and from 0.26 to 0.87 for stress parameters. 33 % (3/9) of stress parameters and 82 % (18/22) of load parameters had an ICC > 0.75. The largest limits of agreement were 41.6 for slap shot 1 after test and 50.4 for 6-min heart rate recovery. The smallest were 0.40 (10-m sprint without a puck) and 5.36 (resting lactate). The intra-rater reliability as shown by the coefficient of variation (CV) was lower for stress than for load parameters (mean CV: 13.4 vs. 4.7). 68 % (15/22) of load parameters and 11 % (1/9) of stress parameters showed a CV below 5 %. CONCLUSION: The IHCT is currently the only ice hockey-specific complex test with scientifically tested reliability and validity that can analyze performance under conditions similar to competition. It is suggested that coaches, fitness coaches and sports scientists explore use of this test as a valid tool to assess players' performance and the effectiveness of training interventions.

Three-dimensional inverse dynamics of the forelimb of Beagles at a walk and trot.

OBJECTIVE To perform 3-D inverse dynamics analysis of the entire forelimb of healthy dogs during a walk and trot. ANIMALS 5 healthy adult Beagles. PROCEDURES The left forelimb of each dog was instrumented with 19 anatomic markers. X-ray fluoroscopy was used to optimize marker positions and perform scientific rotoscoping for 1 dog. Inverse dynamics were computed for each dog during a walk and trot on the basis of data obtained from an infrared motion-capture system and instrumented quad-band treadmill. Morphometric data were obtained from a virtual reconstruction of the left forelimb generated from a CT scan of the same dog that underwent scientific rotoscoping. RESULTS Segmental angles, torque, and power patterns were described for the scapula, humerus, ulna, and carpus segments in body frame. For the scapula and humerus, the kinematics and dynamics determined from fluoroscopy-based data varied substantially from those determined from the marker-based data. The dominant action of scapular rotation for forelimb kinematics was confirmed. Directional changes in the torque and power patterns for each segment were fairly consistent between the 2 gaits, but the amplitude of those changes was often greater at a trot than at a walk. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that control of the forelimb joints of dogs is similar for both a walk and trot. Rotation of the forelimb around its longitudinal axis and motion of the scapula should be reconsidered in the evaluation of musculoskeletal diseases, especially before and after treatment or rehabilitation.