Abstract

Eight healthy adults (6 males and females) were used as subjects. The subjects eyes were covered at all times to prevent any visual feedback. Each metacarpopalangeal joint of digits 2-5 was extended, flexed and pointed to the bisection position in 6 sec (about 2 sec in each position). The difference in the bisection position selected using the index finger with the shoulder, elbow and hand in variety of positions was determined. The deviation from the mid-bisection point and the standard deviation were less when the hand was positioned most comfortably and near the face (natural and near) than when the hand was positioned in the more uncomfortable position and further from the face (unnatural and further). In a second test, the index finger was moved from full extension to the full flexion in increments as small as possible at a rate of one change in position per second. Again, the effect of arm position was determined. In case of the natural and near position, each increment in joint position was smaller than in the unnatural and further position. In the natural and near position, the two point threshold was smallest of all. It was measured at the thumb side of right palm in the proximo-distal direction. Verf.-Referat