Partial weight bearing is a generally accepted principle of rehabilitation following trauma or reconstructive surgery of the lo-wer extremity. Individual dynamic loads during partial weight bearing to a given load level of 200 N were compared in 23 patients who had sustained a fracture of the lower extremity and 11 healthy volunteers using dynamic sole pressure measurements. Excessive dynamic loading compared with the statically pre-tested 200 N level was observed in all groups. Maximum force levels were up to 690 N in young patients and up to 580 N elderly patients beyond the prescribed static load. None of the healthy volunteers was able to keep within the given load of 200 N. The set load level was exceeded by at least 38 N (119%) in the elderly patient group. In com-parison, elderly patients showed statistically significantly higher maximum forces than young patients during the first two test days (p = 0.007 and 0.013). On the 3rd test day the maximum ground contact forces were on average 71 N higher than in the young patients group. Analysis of the force time integrals (impulses transferred to the ground) displayed higher values in the older again than in young patients. The differences were statistically significant during the first two test days (p = 0.006 and 0.037). This study implies that the conventional concept of postoperative partial weight bearing starting from 200 N and a stepwise in-crease of the load level until full weight bearing is not valid during clinical practice.

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Экзоскелетон – это устройство, предназначенное для расширения возможностей человека. В частности, для увеличения усилий, которые может он развивать. Применение этого устройства может быть использовано при выполнении тяжелых работ, погрузочно-разгрузочных работ в местах, где нет возможности применения колёсных погрузчиков, при ремонтных работах на крупных объектах, при аварийно-спасательных операциях и др. Кроме того, экзоскелетон может служить для реабилитации людей, получивших травмы конечностей и/или позвочночника. Экзоскелетон может применяться и в военных целях. В качестве привода звеньев экзоскелетона целесообразно применить гидропривод, так как гидропривод по сравнению с электро- и пневмоприводами имеет ряд преимуществ. Главными из них являются высокое быстродействие и высокая удельная мощность, что позволяет создать достаточно компактный привод. В качестве движителей можно применять поворотные гидродвигатели и гидроцилиндры. Источником энергии может служить двигатель внутреннего сгорания.

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A new experimental platform permits us to study a novel variety of issues of human motor control, particularly full 3-D movements involving the major seven degrees-of-freedom (DOF) of the human arm. We incorporate a seven DOF robot exoskeleton, and minimize weight and inertia through gravity, Coriolis, and inertia compensation, such that subjects’ arm movements are largely unaffected by the manipulandum. Torque perturbations can be individually applied to any or all seven joints of the human arm, thus creating novel dynamic environments, or force fields, for subjects to respond and adapt to. Our first study investigates a joint space force field where the shoulder velocity drives a disturbing force in the elbow joint. Results demonstrate that subjects learn to compensate for the force field within about 100 trials, and, from the strong presence of aftereffects when removing the field in some randomized catch trials, that an inverse dynamics, or internal model, of the force field is formed by the nervous system. Interestingly, while after learning, hand trajectories return to baseline, joint space trajectories remained changed in response to the field, indicating that, besides learning a model of the force field, the nervous system also chose to exploit the null space to minimize the effects of the force field on the realization of the endpoint trajectory plan. We discuss applications of these results in the light of current theories of robotic control, including inverse kinematics and optimal control.

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In this paper an embedded control system for a powered orthosis is presented. The orthosis is used to support the thigh muscles during flexion and extension of the knee while performing common motions like getting up from a chair, walking, or climbing stairs. The user interface of the control system is implemented by evaluating EMG signals from significant thigh muscles to find out the intended motion of the subject. The intended motion is executed with a linear actuator to support the subject’s own muscle force. Results from two experiments are presented. During the trials the torque support from the actuator illustrates the performance of the system.

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We have developed a feedback controller for a walking simulator composed of a treadmill and a rear projection screen, that keeps the subject centered and visual extent consistent across subjects and time while allowing them to set their own walking pace.

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