6. 空間識とスポーツ医学

抄録

　　Research into spatial orientation in the field of sports medicine is progressing very slowly. The reasons for this are the difficulties in recruiting top athletes with superior spatial orientation and in quantitatively evaluating spatial orientation during sports performance. We had the opportunity to perform a spatial orientation experiment on a top gymnast, and our results are presented in this report. Spatial orientation was evaluated using the head tilt perception gain (HTPG) derived from the subjective visual vertical when the head was in either an upright or tilted position. We measured the HTPG when the head alone was tilted, when the entire body was tilted, and when the body was subjected to a centrifugal force in a horizontal direction in the dark or with the aid of a static image that was not tilted from the perspective of the subject. Our results showed that the HPTG of the top gymnast was very accurate, compared with the results for normal individuals, under all the conditions examined. The top gymnast exhibited superior spatial orientation based on information obtained from an otolith, which is a gravity sensor in the inner ear. These results showed that the athlete did not depend on visual information to any significant degree. In addition, we have also discussed previous research regarding spatial orientation, in which eye movement and posture control were used as indicators. We hope that these previous reports, along with the results of the present study, become references for future spatial orientation research in the field of sports medicine.