Assessment of the non-linear behaviour of plastic ankle foot orthoses by the finite element method

The stiffness characteristics of plastic ankle foot orthoses (AFOs) are studied through finite element modelling and stress analysis. Particular attention is given to the modelling and prediction of non-linear AFO behaviour, which has been frequently observed in previous experimental studies but not fully addressed analytically. Both large deformation effects and material non-linearity are included in the formulation and their individual influence on results assessed. The finite element program is subsequently applied to the simulation of a series of tests designed to investigate the relation between AFO trimline location and stiffness for moderate and large rotations. Through careful consideration and identification of key modelling parameters, the developed finite element solution proves to be a reliable and effective alternative means of assessing variations of a typical plastic AFO design so that particular patient requirements could be met, in the long ter

Cutaneous sensibility and peripheral nerve function in patients with unmedicated essential hypertension

Sensorimotor deficits in patients with essential hypertension may be due to impaired nerve function. Cutaneous sensory thresholds, median nerve sensory and motor conduction velocities, andmedian nerve sensory action potential amplitudes were assessed in 30 patients with unmedicated essential hypertension and 29 normotensives. Cutaneous sensory thresholds were higher and sensory action potential amplitudes smaller in hypertensives than normotensives whereas sensory and motor nerve conduction velocities did not differ between groups. These data suggest that hypertension may reduce the number of active sensory nerve fibers without affecting myelination. Sensory action potential amplitudes were inversely related to cutaneous sensory thresholds, suggesting that subclinical axonal neuropathy of sensory afferents may help account for perceptual deficits that characterize hypertension