R P Grelsamer

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Although numerous prominent orthopaedists of the twentieth century considered the patella to be useless, even detrimental, it now is clear that the patella serves an important biomechanical function. It is a complex lever that magnifies the moment arm of the extensor mechanism. The patellofemoral contact area (the fulcrum of the lever) shifts along a(More)
Many clinical studies have emphasized the role of the hamstrings and the iliotibial band on knee mechanics, although few biomechanical studies have investigated it. This study therefore examined two hypotheses: (a) with loading of the hamstrings, the tibia translates posteriorly and rotates externally and the tibial contact pattern shifts anteriorly;(More)
The purpose of this study was to determine the position of the normal patella during routine magnetice resonance imaging (MRI). The literature indicates that the normal patella is positioned laterally relative to the trochlea when the knee is fully extended. As such, a laterally positioned patella on MRI is often interpreted as normal. Yet, in our(More)
Analytic stereophotogrammetry and an interactive computer graphics program were used to obtain first order assessments of joint contact patterns in patellofemoral and glenohumeral joints, simulating normal and abnormal articulations. Precise (90 microns accuracy) computer graphic representations of the humeral head, glenoid, patella, and femoral articular(More)
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