Force-velocity profiling in ice hockey skating: reliability and validity of a simple, low-cost field method.

In recent years, a simple method for force-velocity (F-v) profiling, based on split times, has emerged as a potential tool to examine mechanical variables underlying running sprint performance in field conditions. In this study, the reliability and concurrent validity of F-v profiling based on split times were examined when used for ice hockey skating. It was also tested how a modification of the method, in which the start instant of the sprint is estimated based on optimisation (time shift method), affects the reliability and validity of the method. Both intra- and inter-rater reliability were markedly improved when using the time shift method (approximately 50% decrease in the standard error of measurement). Moreover, the results calculated using the time shift method highly correlated (r > 0.83 for all variables) with the results calculated from a continuously tracked movement of the athlete, which was considered here as the reference method. This study shows that a modification to the previously published simple method for F-v profiling improves intra- and inter-rater reliability of the method in ice hockey skating. The time shift method tested here can be used as a reliable tool to test a player's physical performance characteristic underlying sprint performance in ice hockey skating.

An EMG-Assisted Muscle-Force Driven Finite Element Analysis Pipeline to Investigate Joint- and Tissue-Level Mechanical Responses in Functional Activities: Towards a Rapid Assessment Toolbox.

Joint tissue mechanics (e.g., stress and strain) are believed to have a major involvement in the onset and progression of musculoskeletal disorders, e.g., knee osteoarthritis (KOA). Accordingly, considerable efforts have been made to develop musculoskeletal finite element (MS-FE) models to estimate highly detailed tissue mechanics that predict cartilage degeneration. However, creating such models is time-consuming and requires advanced expertise. This limits these complex, yet promising, MS-FE models to research applications with few participants and makes the models impractical for clinical assessments. Also, these previously developed MS-FE models have not been used to assess activities other than gait. This study introduces and verifies a semi-automated rapid state-of-the-art MS-FE modeling and simulation toolbox incorporating an electromyography- (EMG) assisted MS model and a muscle-force driven FE model of the knee with fibril-reinforced poro(visco)elastic cartilages and menisci. To showcase the usability of the pipeline, we estimated joint- and tissue-level knee mechanics in 15 KOA individuals performing different daily activities. The pipeline was verified by comparing the estimated muscle activations and joint mechanics to existing experimental data. To determine the importance of the EMG-assisted MS analysis approach, results were compared to those from the same FE models but driven by static-optimization-based MS models. The EMG-assisted MS-FE pipeline bore a closer resemblance to experiments compared to the static-optimization-based MS-FE pipeline. Importantly, the developed pipeline showed great potential as a rapid MS-FE analysis toolbox to investigate multiscale knee mechanics during different activities of individuals with KOA.

Assessment of early treatment response by rapid cardiothoracic ultrasound in acute heart failure: Cardiac filling pressures, pulmonary congestion and mortality.

BACKGROUND: It is unclear how to optimally monitor acute heart failure (AHF) patients. We evaluated the timely interplay of cardiac filling pressures, brain natriuretic peptides (BNPs), lung ultrasound (LUS) and symptoms during AHF treatment. METHODS: We enrolled 60 patients who had been hospitalised for AHF. Patients were examined with a rapid cardiothoracic ultrasound (CaTUS) protocol, combining LUS and focused echocardiographic evaluation of cardiac filling pressures (i.e. medial E/e' and inferior vena cava index [IVCi]). CaTUS was done at 0, 12, 24 and 48 hours (±3 hours) and on the day of discharge, alongside clinical evaluation and laboratory samples. Patients free of congestion (B lines or pleural fluid) on LUS at discharge were categorised as responders, whereas the rest were categorised as non-responders. Improvement in congestion parameters was evaluated separately in these groups. The effect of congestion parameters on prognosis was also analysed. RESULTS: Responders experienced a significantly larger decline in E/e' (2.58 vs. 0.38, p = 0.037) and dyspnoea visual analogue scale (1-10) score (7.68 vs. 3.57, p = 0.007) during the first 12 hours of treatment, while IVCi and BNPs declined later without no such rapid initial decline. Among patients experiencing a >3 U decline in E/e' during the first 12 hours of treatment, 18/21 were to become responders ( p < 0.001). LUS response was the only congestion parameter independently predicting both 6-month survival regarding all-cause mortality and the composite endpoint of all-cause mortality or rehospitalisation for AHF. CONCLUSION: E/e' seemed like the most useful congestion parameter for monitoring early treatment response, predicting prognostically beneficial resolution of pulmonary congestion.

Transthoracic echocardiography for non-invasive assessment of coronary vasodilator function after DES implantation.

AIMS: Coronary vasodilator dysfunction has been reported after drug-eluting stent (DES) implantation. Recent ESC guidelines suggest that transthoracic echocardiography (TTE) may be considered for assessment of coronary flow reserve (CFR) and microvascular disease in patients with stable angina, but its reliability has not been tested in patients with DES. We sought to assess the agreement between TTE (CFRTTE) and invasive thermodilution-derived CFR (CFRThermodilution) as well as their association with index of microcirculatory resistance (IMR) in mid-term follow-up after percutaneous coronary intervention for acute coronary syndrome. METHODS AND RESULTS: CFRTTE and CFRThermodilution were assessed 3 months after DES implantation in the left anterior descending artery in 24 patients. Patients with haemodynamically significant epicardial stenosis (fractional flow reserve <0.75) were excluded. Correlation between the two methods was good (r = 0.71, P < 0.001), but CFRThermodilution (mean ± SD) tended to be higher (3.17 ± 1.00 vs. 2.87 ± 0.72; mean difference 0.29, 95% confidence interval -0.06 to 0.59). In Bland-Altman analysis, there was a trend towards a greater difference in the range of higher invasive values. Nevertheless, TTE was successful in discriminating moderately impaired CFR (≤2.5) (P = 0.001) and severely impaired CFR (≤2.0) (P < 0.001) when compared with an invasive method. No association between either CFR measurements vs. IMR measurement was detected, suggesting that in addition to microcirculatory function, CFR also accounts for epicardial vasodilator function in the absence of haemodynamically significant stenosis. CONCLUSION: TTE is a feasible and reliable method for the assessment of CFR and vasodilator dysfunction after DES implantation. Values obtained with this method successfully find abnormal CFR confirmed with the invasive thermodilution method.

Endovenous obliteration versus conventional stripping operation in the treatment of primary varicose veins: a randomized controlled trial with comparison of the costs.

OBJECTIVE: The aim of this randomized study was to compare a new method of endovenous saphenous vein obliteration (Closure System, VNUS Medical Technologies, Inc, Sunnyvale, Calif) with the conventional stripping operation in terms of short-term recovery and costs. METHODS: Twenty-eight selected patients for operative treatment of primary greater saphenous vein tributary varicose veins were randomly assigned to endovenous obliteration (n = 15) or stripping operation (n = 13). Postoperative pain was daily assessed during the 1st week and on the 14th postoperative day. The length of sick leave was determined. The RAND-36 health survey was used to assess the patient health-related quality of life. The patient conditions were controlled 7 to 8 weeks after surgery, and patients underwent examination with duplex ultrasonography. The comparison of costs included both direct medical costs and costs resulting from lost of productivity of the patients. Costs that were similar in the study groups were not considered in the analysis. RESULTS: All operations were successful, and the complication rates were similar in the two groups. Postoperative average pain was significantly less severe in the endovenous obliteration group as compared with the stripping group (at rest: 0.7, standard deviation [SD] 0.5, versus 1.7, SD 1.3, P =.017; on standing: 1.3, SD 0.7, versus 2.6, SD 1.9, P =.026; on walking: 1.8, SD 0.8, versus 3.0, SD 1.8, P =.036; with t test). The sick leaves were significantly shorter in the endovenous obliteration group (6.5 days, SD 3.3 days, versus 15.6 days, SD 6.0 days; 95% CI, 5.4 to 12.9; P <.001, with t test). Physical function was also restored faster in the endovenous obliteration group. The estimated annual investment costs of the closure operation were US $3360. The other direct medical costs of the Closure operation were about $850, and those of the conventional treatment were $360. With inclusion of the value of the lost working days, the Closure treatment was cost-saving for society, and when 40% of the patients are retired (or 60% of the productivity loss was included), the Closure procedure became cost-saving at a level of 43 operations per year. CONCLUSION: Endovenous obliteration may offer advantages over the conventional stripping operation in terms of reduced postoperative pain, shorter sick leaves, and faster return to normal activities, and it appears to be cost-saving for society, especially among employed patients. Because the procedure is also associated with shorter convalescence, this new method may potentially replace conventional varicose vein surgery.