Quantitative and qualitative running gait analysis through an innovative video-based approach

Quantitative and qualitative running gait analysis allows the early identification and the longitudinal monitoring of gait abnormalities linked to running-related injuries. A promising calibration- and marker-less video sensor-based technology (i.e., Graal), recently validated for walking gait, may also offer a time- and cost-efficient alternative to the gold-standard methods for running. This study aim was to ascertain the validity of an improved version of Graal for quantitative and qualitative analysis of running. In 33 healthy recreational runners (mean age 41 years), treadmill running at self-selected submaximal speed was simultaneously evaluated by a validated photosensor system (i.e., Optogait-the reference methodology) and by the video analysis of a posterior 30-fps video of the runner through the optimized version of Graal. Graal is video analysis software that provides a spectral analysis of the brightness over time for each pixel of the video, in order to identify its frequency contents. The two main frequencies of variation of the pixel's brightness (i.e., F1 and F2) correspond to the two most important frequencies of gait (i.e., stride frequency and cadence). The Optogait system recorded step length, cadence, and its variability (vCAD, a traditional index of gait quality). Graal provided a direct measurement of F2 (reflecting cadence), an indirect measure of step length, and two indexes of global gait quality (harmony and synchrony index). The correspondence between quantitative indexes (Cadence vs. F2 and step length vs. Graal step length) was tested via paired t-test, correlations, and Bland-Altman plots. The relationship between qualitative indexes (vCAD vs. Harmony and Synchrony Index) was investigated by correlation analysis. Cadence and step length were, respectively, not significantly different from and highly correlated with F2 (1.41 Hz \ub1 0.09 Hz vs. 1.42 Hz \ub1 0.08 Hz, p = 0.25, r2 = 0.81) and Graal step length (104.70 cm \ub1 013.27 cm vs. 107.56 cm \ub1 13.67 cm, p = 0.55, r2 = 0.98). Bland-Altman tests confirmed a non-significant bias and small imprecision between methods for both parameters. The vCAD was 1.84% \ub1 0.66%, and it was significantly correlated with neither the Harmony nor the Synchrony Index (0.21 \ub1 0.03, p = 0.92, r2 = 0.00038; 0.21 \ub1 0.96, p = 0.87, r2 = 0.00122). These findings confirm the validity of the optimized version of Graal for the measurement of quantitative indexes of gait. Hence, Graal constitutes an extremely time- and cost-efficient tool suitable for quantitative analysis of running. However, its validity for qualitative running gait analysis remains inconclusive and will require further evaluation in a wider range of absolute and relative running intensities in different individuals

Effects in short and long term of global postural reeducation (GPR) on chronic low back pain: A controlled study with one-year follow-up

Objective. Comparing global postural reeducation (GPR) to a standard physiotherapy treatment (PT) based on active exercises, stretching, and massaging for improving pain and function in chronic low back pain (CLBP) patients. Design. Prospective controlled study. Setting. Outpatient rehabilitation facility. Participants. Adult patients with diagnosis of nonspecific, chronic (>6 months) low back pain. Interventions. Both treatments consisted of 15 sessions of one hour each, twice a week including patient education. Measures. Roland Morris Disability Questionnaire to evaluate disability, and Numeric Analog Scale for pain. A score change >30% was considered clinically significant. Past treatments, use of medications, smoking habits, height, weight, profession, and physical activity were also recorded on baseline, on discharge, and 1 year after discharge (resp., T0, T1, and T2). Results. At T0 103 patients with cLBP (51 cases and 52 controls) were recruited. The treatment (T1) has been completed by 79 (T1) of which 60 then carried out the 1-year follow-up (T2). Both GPR and PT at T1 were associated with a significant statistical and clinical improvement in pain and function, compared to T0. At T2, only pain in GPR still registered a statistically significant improvement

Sustainable exploitation of paper mill wastes: a resource to re-use in the paper factory

In the papermaking industry, billions of tonnes of paper mill wastes are globally produced as wastes every year. These include cellulosic and inorganic sludges, which are traditionally landfilled, leading to environmental and economic issues. For these reasons, it is urgent to develop new sustainable strategies to exploit these fractions. Up to now, these sludges have been exploited i) for land application (as soil amendment/substrate), ii) for energy recovery and iii) for the production of bio-composites. However, the above possibilities involve the direct use of the bulk wastes, without fractionating/exploiting each feedstock component. In the perspective of the valorisation of the different components, the present investigation has considered different strategies: i) a thermal treatment, ii) an alkaline and iii) a mechanical one, aimed at the fractionation and recovery of the two main components of cellulosic and inorganic sludge, cellulose and calcium carbonate, respectively, that could be advantageously reused within the same papermaking process

Estimation of Spatiotemporal Gait Parameters in Walking on a Photoelectric System: Validation on Healthy Children by Standard Gait Analysis

The use of stereophotogrammetry systems is challenging when targeting children's gait analysis due to the time required and the need to keep physical markers in place. For this reason, marker-less photoelectric systems appear to be a solution for accurate and fast gait analysis in youth. The aim of this study is to validate a photoelectric system and its configurations (LED filter setting) on healthy children, comparing the kinematic gait parameters with those obtained from a three-dimensional stereophotogrammetry system. Twenty-seven healthy children were enrolled. Three LED filter settings for the OptoGait were compared to the BTS P6000. The analysis included the non-parametric 80% limits of agreement and the intraclass correlation coefficient (ICC). Additionally, normalised limits of agreement and bias (NLoAs and Nbias) were compared to the clinical experience of physical therapists (i.e., assuming an error lower than 5% is acceptable). ICCs showed excellent consistency for most of the parameters and filter settings; NLoAs varied between 1.39% and 12.62%. An inverse association between the number of LEDs for filter setting and the bias values was also observed. Observations confirm the validity of the OptoGait system for the evaluation of spatiotemporal gait parameters in children

Photometric determination of the mass accretion rates of pre-main sequence stars. I. Method and application to the SN1987A field

We have developed and successfully tested a new self-consistent method to reliably identify pre-main sequence (PMS) objects actively undergoing mass accretion in a resolved stellar population, regardless of their age. The method does not require spectroscopy and combines broad-band V and I photometry with narrow-band Halpha imaging to: (1) identify all stars with excess Halpha emission; (2) derive their Halpha luminosity L(Halpha); (3) estimate the Halpha emission equivalent width; (4) derive the accretion luminosity L_acc from L(Halpha); and finally (5) obtain the mass accretion rate M_acc from L_acc and the stellar parameters (mass and radius). By selecting stars with photometric accuracy in Halpha better than 15%, the statistical uncertainty on the derived M_acc is typically <17% and is dictated by the precision of the Halpha photometry. Systematic uncertainties, of up to a factor of 3 on the value of M_acc, are caused by our incomplete understanding of the physics of the accretion process and affect all determinations of the mass accretion rate, including those based on a spectroscopic Halpha line analysis. As an application of our method, we study a field of 9.16 arcmin2 around SN1987A, using existing HST photometry. We identify as bona-fide PMS stars a total of 133 objects with a Halpha excess above the 4 sigma level and a median age of 13.5 Myr. Their median mass accretion rate of 2.6x10-8 Msolar/yr is in excellent agreement with previous determinations based on the U-band excess of the stars in this field, and with the value measured for G-type PMS stars in the Milky Way. Their L_acc shows a strong dependence on their distance from a group of hot massive stars in the field and suggests that the UV radiation of the latter is rapidly eroding the circumstellar discs around PMS stars.Comment: 18 pages, 18 figures, accepted for publication in the Astrophysical Journa

Risk factors for hepatitis C virus infection among nonintravenous-drug-using heterosexuals attending a clinic for sexually transmitted disease in Italy

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