ABSTRACT
To examine personal space perception, a method of identifying joint position was determined by having the subject equally bisect the joint angle, by producing a minimum increment in change of position and by selecting a threshold for two-point discrimination using the metacarpophalangeal joint of digits 2-5.<BR>Eight healthy adults (6 males and 2 females) were used as subjects. The subjects' eyes were covered at all times to prevent any visual feedback.<BR>Each metacarpophalangeal 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”) .<BR>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.<BR>In case of“the natural and near”position, each increment in joint position was smaller than in“the unnatural and further”position.<BR>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.<BR>These results suggest that personal space perception of metacarpophalangeal joint is affected by the position of adjoining limb segments.
ABSTRACT
To examine personal space perception, a method of identifying joint position was determined by having the subject equally bisect the joint angle, by producing a minimum increment in change of position and by selecting a threshold for two-point discrimination using the metacarpophalangeal joint of digits 2-5.<BR>Eight healthy adults (6 males and 2 females) were used as subjects. The subjects' eyes were covered at all times to prevent any visual feedback.<BR>Each metacarpophalangeal 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”) .<BR>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.<BR>In case of“the natural and near”position, each increment in joint position was smaller than in“the unnatural and further”position.<BR>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.<BR>These results suggest that personal space perception of metacarpophalangeal joint is affected by the position of adjoining limb segments.
ABSTRACT
To examine the variation in the knee extension force and the integrated electromyogram from rectus femoris, medial vastus and lateral vastus muscles with the knee joint angle in growing children, measurements were conducted in 61 school boys aged from 7 to 12 years old. Anthropometric measurements were also done on the body height, the lower limb length, and so on. Results obtained were as follows.<BR>1) Ratio of the lower limb length comparing with the body height increased with the grade.<BR>2) Maximal force at each joint angle in each grade was shifted peak from 70°to 90°with the grade.<BR>3) The pattern of the integrated surface electromyogram from rectus femoris, medial vastus or lateral vastus muscle at each joint angle was the same in all of the grade. The integrated electromyogram at the maximal voluntary contraction was maximal at 45°of the knee joint angle in the rectus femoris muscle, at 110°in the medial vastus and at 90°in the lateral vastus muscle.