Having established the outline designs for each of the four types of knee orthoses, the other requirements which must be taken into account in compiling the detail designs must be con-sidered. The most significant of these are the problems of attaching the orthosis securely to the leg. As the lower limb essentially tapers from hip to ankle, knee orthosis have a ten-dency to slip distally under the action of gravity and the inertial forces generated at heel-strike. This will lead to misalignment of knee joint hinges with a subsequent reduction in knee flexion and sometimes also significant discom-fort. A compromise therefore needs to be sought between attaching the orthosis too lightly to the limb and hence risking slippage of the device, and strapping the orthosis so firmly that it is uncomfortable. It has been in an attempt to circumvent such difficulties that techniques such as suspension from a hip or waistband, or the attachment of the orthosis to below-knee elements anchored in the shoe have been tried.
- VicLv 61 0 年前最佳解答