299 research outputs found
Techniques for measuring weight bearing during standing and walking
OBJECTIVE: To classify and assess techniques for measuring the amount of weight bearing during standing and walking.BACKGROUND: A large variety of weight bearing measuring techniques exists. This review describes their advantages and limitations to assist clinicians and researchers in selecting a technique for their specific application in measuring weight bearing.METHODS: A literature search was performed in Pubmed-Medline, CINAHL, and EMBASE. Measurement techniques were classified in 'clinical examination', 'scales', 'biofeedback systems', 'ambulatory devices' and 'platforms', and assessed on aspects of methodological quality, application, and feasibility.RESULTS: A total of 68 related articles was evaluated. The clinical examination technique is a crude method to estimate the amount of weight bearing. Scales are useful for static measurements to evaluate symmetry in weight bearing. Biofeedback systems give more reliable, accurate and objective data on weight bearing compared to clinical examination and scales, but the high costs could limit their use in physical therapy departments. The ambulatory devices can measure weight bearing with good accuracy and reliability in the hospital and at home. Platforms have the best methodological quality, but are mostly restricted to a gait laboratory, need trained personnel, and are expensive.CONCLUSIONS: The choice of a technique largely depends upon the criteria discussed in this review; however the clinical utilisation, the research question posed, and the available budget also play a role. The new developments seen in the field of 'ambulatory devices' are aimed at extending measuring time, and improved practicality in data collection and data analysis. For these latter devices, however, mainly preliminary studies have been published about devices that are not (yet) commercially available.</p
Analytic structure and power-series expansion of the Jost function for the two-dimensional problem
For a two-dimensional quantum mechanical problem, we obtain a generalized
power-series expansion of the S-matrix that can be done near an arbitrary point
on the Riemann surface of the energy, similarly to the standard effective range
expansion. In order to do this, we consider the Jost-function and analytically
factorize its momentum dependence that causes the Jost function to be a
multi-valued function. The remaining single-valued function of the energy is
then expanded in the power-series near an arbitrary point in the complex energy
plane. A systematic and accurate procedure has been developed for calculating
the expansion coefficients. This makes it possible to obtain a semi-analytic
expression for the Jost-function (and therefore for the S-matrix) near an
arbitrary point on the Riemann surface and use it, for example, to locate the
spectral points (bound and resonant states) as the S-matrix poles. The method
is applied to a model simlar to those used in the theory of quantum dots.Comment: 42 pages, 9 figures, submitted to J.Phys.
A 5-year follow-up study of Alfredson's heel-drop exercise programme in chronic midportion Achilles tendinopathy
Background: Eccentric exercises have the most evidence in conservative treatment of midportion Achilles tendinopathy. Although short-term studies show significant improvement, little is known of the long-term (>3 years) results. Aim: To evaluate the 5-year outcome of patients with chronic midportion Achilles tendinopathy treated with the classical Alfredson's heel-drop exercise programme. Study design: Part of a 5-year follow-up of a previously conducted randomised controlled trial. Methods: 58 patients (70 tendons) were approached 5 years after the start of the heel-drop exercise programme according to Alfredson. At baseline and at 5-year follow-up, the validated Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire score, pain status, alternative treatments received and ultrasonographic neovascularisation score were recorded. Results: In 46 patients (58 tendons), the VISA-A score significantly increased from 49.2 at baseline to 83.6 after 5 years (p<0.001) and from the 1-year to 5-year follow-up from 75.0 to 83.4 (p<0.01). 39.7% of the patients were completely pain-free at follow-up and 48.3% had received one or more alternative treatments. The sagittal tendon thickness decreased from 8.05 mm (SD 2.1) at baseline to 7.50 mm (SD 1.6) at the 5-year follow-up (p=0.051). Conclusion: At 5-year follow-up, a significant increase of VISA-A score can be expected. After the 3-month Alfredson's heel-drop exercise programme, almost half of the patients had received other therapies. Although improvement of symptoms can be expected at long term, mild pain may remain
Universal Two-Body Spectra of Ultracold Harmonically Trapped Atoms in Two and Three Dimensions
We consider the spectrum of two ultracold harmonically trapped atoms
interacting via short-range interactions. The Green's function approach is used
to unify the two and three dimensional cases. We derive criteria for the
universality of the spectrum, i.e. its independence of the details of the
short-range interaction. The results in three dimensions are examplified for
narrow s-wave Feshbach resonances and we show how effective range corrections
can modify the rearrangement of the level structure. However, this requires
extremely narrow resonances or very tight traps that are not currently
experimentally available. In the two-dimensional case we discuss the p-wave
channel in detail and demonstrate how the non-universality of the spectrum
arises within the Green's function approach. We then show that the spectrum is
not particularly sensitive to the short-distance details in the case when the
two-body interaction has a bound state.Comment: 20 pages including appendices, 6 figures, one-column accepted versio
Feshbach resonances in rubidium 87: Precision measurement and analysis
More than 40 Feshbach resonances in rubidium 87 are observed in the magnetic
field range between 0.5 and 1260 G for various spin mixtures in the lower
hyperfine ground state. The Feshbach resonances are observed by monitoring the
atom loss, and their positions are determined with an accuracy of 30 mG. In a
detailed analysis, the resonances are identified and an improved set of model
parameters for the rubidium interatomic potential is deduced. The elastic width
of the broadest resonance at 1007 G is predicted to be significantly larger
than the magnetic field resolution of the apparatus. This demonstrates the
potential for applications based on tuning the scattering length.Comment: figure 2 corrected; minor changes in the tex
Supervised exercise therapy versus usual care for patellofemoral pain syndrome: an open label randomised controlled trial
Objective To assess the effectiveness of supervised exercise therapy compared with usual care with respect to recovery, pain, and function in patients with patellofemoral pain syndrome
Perturbations in myocardial perfusion and oxygen balance in swine with multiple risk factors
Comorbidities of ischemic heart disease, including diabetes mellitus (DM), hypercholesterolemia (HC) and chronic kidney disease (CKD), are associated with coronary microvascular dysfunction (CMD). Increasing evidence suggests that CMD may contribute to myocardial ‘Ischemia and No Obstructive Coronary Artery disease’ (INOCA). In the present study, we tested the hypothesis that CMD results in perturbations in myocardial perfusion and oxygen delivery using a novel swine model with multiple comorbidities. DM (streptozotocin), HC (high-fat diet) and CKD (renal embolization) were induced in 10 female swine (DM + HC + CKD), while 12 healthy female swine on a normal diet served as controls (Normal). After 5 months, at a time when coronary atherosclerosis was still negligible, myocardial perfusion, metabolism, and function were studied at rest and during treadmill exercise. DM + HC + CKD animals showed hyperglycemia, hypercholesterolemia, and impaired kidney function. During exercise, DM + HC + CKD swine demonstrated perturbations in myocardial blood flow and oxygen delivery, necessitating a higher myocardial oxygen extraction—achieved despite reduced capillary density—resulting in lower coronary venous oxygen levels. Moreover, myocardi
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