The transfer characteristics of a turn-buckle attachment for a knee orthosis are described, based on the relation of output to input moments in a rigid-body model. The law of cosines can be applied to this model to obtain a relation between the angle of the knee joint and the number of revolutions of the grip portion of the turn-buckle device, beginning from its shortest length. Differentiation of this relation with respect to the number of revolutions reveals the rate at which the knee angle increases. An analysis of forces for a “wedge model”, which involves a screw with triangular threads, is compared with a similar analysis for a “slope model”, which contains a screw with square threads. A wedge model would require exactly twice as great a force to maintain a given load pressure at the knee as would a similarly constructed slope model. For an orthosis such as that shown in Figure 1, which contains screws with triangular threads, the following observations can be made. 1) The angle at the knee approximates a linear function of the number of revolutions of the grip, deviating no more than ±2.5 degrees. As the knee joint approaches extension, however, the change in its increment angle per revolution of the grip begins to increase rapidly. 2) Assuming the screws in the turn-buckle attachment to have a friction coefficient of about 0.2, the moment exerted by the orthosis to extend the knee is on the order of 50 times the moment applied at the grip to effect that extension. 3) At a given load pressure, the input moment necessary to extend the knee would be much more than that necessary to release the load pressure, this ratio increasing as the friction coefficient decreases. 4) Screws with triangular threads are preferred to those with square threads for use in a turn-buckle attachment, since the greater coefficient of friction resulting from the former type of screw contributes stability needed for such a device.
A comparative analysis has been studied in following two groups about the activities of daily living in ambulation of stroke patient. 1) Rehabilitation group: 94 patients who were received institutional rehabilitation care at the Fukuoka Higashi National Hospital. 2) Non-rehabilitation group: 48 patients who were admitted to the Second Department of Internal Medicine, Kyushu University. Since disability in stroke patients sometimes may be spontaneously recovered, the duration from the terminal episode were matched in the two groups. The two groups were similar in age, sex and grades of disability in ambulation. Result to this studies showes that 79.8per cent of the patients in rehabilitation group achieved in the independent or T cane gait at discharge, on the other hand, only 39.3 per cent of the patients in non-rehabilitation group achieved at the same period. But in these three years of the follow-up study, the number of the independent or T cane gait patients remarkably decreased from 79.8per cent to 48.9per cent, and non-rehabilitation group decreased from 39.6per cent to 33.3per cent. This shows that the institutional rehabilitation in the stroke patients are effective, but the maintenance of achieved activities of daily living in ambulation are very difficult for rehabilitated patients in three years. The causes of degradation in activities of daily living of rehabilitated patients were recurrence of stroke, complication, accident such as falling down or fracture and unknown etiology. Fifty-five per cent of the causes of degradation were occured in unknown etiology. So that it is very important to research the unknown etiology continuously.