Abstract
Performance of ski-jump is mostly dominated by the skill of take-off. Pressure given to jumping boad and time of action at take-off were recorded electrically and analyzed. Experiments were carried out in following two ways in laboratory where subjects took crouching position on the wood board to which straingauge was attached: (1) taking off as soon as light signal was given (2) taking off when subjects imagnarily thought that they came approaching at the line of taking-off Results of the experiment were as follows; Pressure was recorded as (1) 116.9kg (2) 97.8kg Time of action measured when taking off was (1) 405.8 msec.(2) 396.2 msec. Direction of jump-flying was considerably related with changes in joint angles at waist, knee and foot. Postural changes and flying direction were taken by means of photographic tracergram. Beam of lamps which were fixed on the waist ran toward reasonable direction of 40-45 degree of angle, while individual differences were observed in the light beams from the lamps which was attached to the knee and the foot joint.
