614 research outputs found

    Re-presentations of motherhood in the writings of Tillie Olsen and Sylvia Plath

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    EMG Analysis of Lower Extremity Muscle Activity during Wall Slides with Varying Foot Positions

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    Knee injuries are among the most common injuries seen in a physical therapy clinic. Nearly all rehabilitation programs following a knee injury involve quadriceps muscle strengthening. One popular and safe method of quadriceps strengthening often used is the wall slide. There is, however, debate and little research indicating whether or not changing the foot position used during wall slides alters the muscle activity during this exercise. The purpose of this study was to provide a better understanding of the muscle activity during wall slides with feet in various positions so that more accurate rehabilitation protocols may be developed in the physical therapy clinic. Thirty participants without previous history of knee pathologies were recruited to participate in this study. The subjects were asked to perform a series of 5 wall slides in 3 different foot positions. These positions were indicated by placing marks on non-skid floor mats. Foi the first position, subjects were asked to line up their second toe and heal with a line perpendicular to the wall. Position 2 was performed by having the subjects rotate their feet so that their second toe lined up with a line 30 degrees inward from the first line with resultant hip internal rotation. The third position was obtained in the same way as the second position, with the only difference being that rotation was done in an outward direction. These 3 positions were referred to as neutral rotation, 30 degrees of internal rotation, and 30 degrees of external rotation. The order of these positions was randomly selected and the wall slides were performed to a knee flexion angle of 45 degrees. Electromyographic activity was recorded for the rectus femoris, vastus lateralis, vastus medialis, biceps femoris, gastrocnemius, and anterior tibialis muscles of the subjects\u27 dominant leg. The results of this study indicated that there is no significant difference in EMG activity of the quadriceps muscles (vastus lateralis, vastus medialis, and rectus femoris) across foot positions. The results did, however, indicate a significant difference in EMG activity across foot positions for the anterior tibialis, biceps femoris, and gastrocnemius muscle. These results suggested that clinicians may need to address foot position during wall slides when these muscles are involved following a knee injury. The results also suggested that the patient\u27s foot position during a wall slide is not an important factor to consider when developing a rehabilitation program for quadriceps muscle strengthening following a knee injury. Allowing the patient to perform the wall slide in a position of comfort should then be the clinician\u27s main concern

    Topological Observables in Semiclassical Field Theories

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    We give a geometrical set up for the semiclassical approximation to euclidean field theories having families of minima (instantons) parametrized by suitable moduli spaces M{\cal M}. The standard examples are of course Yang-Mills theory and non-linear σ\sigma-models. The relevant space here is a family of measure spaces \tilde {\cal N} \ra {\cal M}, with standard fibre a distribution space, given by a suitable extension of the normal bundle to M{\cal M} in the space of smooth fields. Over N~\tilde {\cal N} there is a probability measure dμd\mu given by the twisted product of the (normalized) volume element on M{\cal M} and the family of gaussian measures with covariance given by the tree propagator CϕC_\phi in the background of an instanton ϕ∈M\phi \in {\cal M}. The space of ``observables", i.e. measurable functions on (N~, dμ\tilde {\cal N}, \, d\mu), is studied and it is shown to contain a topological sector, corresponding to the intersection theory on M{\cal M}. The expectation value of these topological ``observables" does not depend on the covariance; it is therefore exact at all orders in perturbation theory and can moreover be computed in the topological regime by setting the covariance to zero.Comment: 11 page
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