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

De effectiviteit van valklinieken in Nederland

Recent zijn er twee artikelen gepubliceerd, waarbij er gekeken is naar de effectiviteit van een multifactorieel valpreventieprogramma uitgevoerd door valklinieken in Nederland. Beide artikelen laten negatieve resultaten zien. Het is echter de vraag of deze twee studies representatief zijn voor de situatie zoals het er in de meeste valklinieken in Nederland aan toegaat. Twee belangrijke verschillen zitten in de patiëntenselectie en de uitvoer van het valpreventieprogramma. Op een valkliniek is het belangrijk die patiënten te selecteren met het hoogste valrisico (≥ 2 valincidenten/ jaar en/of ≥ 4 valrisicofactoren) en om een actieve, directe aanpak van het valprobleem na te streven om de effectiviteit van de valkliniek te optimaliseren

PTH analoga: vergelijkbaar of verschillend?

Momenteel bestaan er 2 verschillende PTH-analoga: PTH 1-34 (teriparatide) en PTH 1-84. Teriparatide is in Nederland vanaf februari 2005 verkrijgbaar; inmiddels is sinds januari 2007 ook PTH 1-84 beschikbaar. Teriparatide is geregistreerd voor de behandeling van vastgestelde osteoporose bij postmenopauzale vrouwen en bij mannen met een verhoogd risico op botbreuken, PTH 1-84 voor de behandeling van postmenopauzale vrouwen met een verhoogd fractuurrisico. Teriparatide bestaat uit de eerste 34 aminozuren van het humane parathormoon, op recombinante wijze geproduceerd, het actieve gedeelte van dit hormoon. De resterende 50 aminozuren staan te boek als het “inactieve” gedeelte van het parathormoon. PTH 1-84 daarentegen bestaat uit 84 aminozuren, het “volledige” parathormoon; ook dit wordt recombinant gesynthetiseerd. In dit artikel zal worden ingegaan op de overeenkomsten en de eventuele verschillen in effectiviteit en veiligheid van teriparatide en PTH 1-84. Wat betreft de effectiviteit is voor beide middelen een overtuigende reductie van wervelfracturen aangetoond; alleen voor teriparatide is reductie van niet-wervelfracturen aangetoond. Een andere belangrijke overeenkomst is dat beide middelen sterk anabool werkzaam zijn, het werkingsmechanisme is essentieel verschillend van bisfosfonaten en van strontiumranelaat. Beide middelen zijn daarmee voor oudere patiënten met ernstige osteoporose een welkome aanvulling van het therapeutisch arsenaal. Dit betreft vooral patiënten die ondanks behandeling met bisfosfonaten of raloxifen of strontiumranelaat na twee wervelinzakkingen opnieuw één of meerdere fracturen krijgen (“inadequate response”), dan wel bovengenoemde drie middelen niet verdragen. Het is hierbij van belang dat beide middelen voorgeschreven dienen te worden door de behandelend medisch specialist, bijvoorbeeld de klinisch geriater. Vanwege de hoge kosten van deze medicamenten, worden deze middelen alleen vergoed bij patiënten die aan bovenstaande criteria voldoen

Radio-Frequency Spectroscopy of Ultracold Fermions

Radio-frequency techniques were used to study ultracold fermions. We observed the absence of mean-field "clock" shifts, the dominant source of systematic error in current atomic clocks based on bosonic atoms. This is a direct consequence of fermionic antisymmetry. Resonance shifts proportional to interaction strengths were observed in a three-level system. However, in the strongly interacting regime, these shifts became very small, reflecting the quantum unitarity limit and many-body effects. This insight into an interacting Fermi gas is relevant for the quest to observe superfluidity in this system.Comment: 6 pages, 6 figure

Metastable neon collisions: anisotropy and scattering length

In this paper we investigate the effective scattering length $a$ of spin-polarized Ne*. Due to its anisotropic electrostatic interaction, its scattering length is determined by five interaction potentials instead of one, even in the spin-polarized case, a unique property among the Bose condensed species and candidates. Because the interaction potentials of Ne* are not known accurately enough to predict the value of the scattering length, we investigate the behavior of $a$ as a function of the five phase integrals corresponding to the five interaction potentials. We find that the scattering length has five resonances instead of only one and cannot be described by a simple gas-kinetic approach or the DIS approximation. However, the probability for finding a positive or large value of the scattering length is not enhanced compared to the single potential case. The complex behavior of $a$ is studied by comparing a quantum mechanical five-channel numerical calculation to simpler two-channel models. We find that the induced dipole-dipole interaction is responsible for coupling between the different |\Omega> states, resulting in an inhomogeneous shift of the resonance positions and widths in the quantum mechanical calculation as compared to the DIS approach. The dependence of the resonance positions and widths on the input potentials turns out to be rather straightforward. The existence of two bosonic isotopes of Ne* enables us to choose the isotope with the most favorable scattering length for efficient evaporative cooling towards the Bose-Einstein Condensation transition, greatly enhancing the feasibility to reach this transition.Comment: 13pages, 8 eps figures, analytical model in section V has been remove

Inter-isotope determination of ultracold rubidium interactions from three high-precision experiments

Combining the measured binding energies of four of the most weakly bound rovibrational levels of the $^{87}$Rb$_2$ molecule with the results of two other recent high-precision rubidium experiments, we obtain exceptionally strong constraints on the atomic interaction parameters in a highly model independent analysis. The comparison of $^{85}$Rb and $^{87}$Rb data, where the two isotopes are related by a mass scaling procedure, plays a crucial role. Using the consistent picture of the interactions that thus arises we are led to predictions for scattering lengths, clock shifts, Feshbach resonance fields and widths with an unprecedented level of accuracy. To demonstrate this, we predict two Feshbach resonances in mixed-spin scattering channels at easily accessible magnetic field strengths, which we expect to play a role in the damping of coherent spin oscillations