Orientation versus motion visual cues to control sensorimotor skills in some acrobatic leaps

Abstract

Eight healthy male sportsmen, trained to compete at national level, were asked to perform three types of acrobatic leaps on the trampoline: twisting from stand to stand, backward somersault, and full backward twisting, with three different visual conditions: darkness, stroboscopic lighting (12 flashes per second), and normal lighting. Performances were assessed using the standardized marking system of the international gymnastic federation. All the acrobatic figures were carried out without any error in the normal lighting. However, imbalance on landing was often observed in stroboscopic lighting or in darkness, making the standard deviation significantly higher than in normal conditions. In the case of backward somersault, results were significantly better in strobe lighting than in darkness. Backward somersault was also the only case where the rotation of the body was significantly underestimated in darkness (backward imbalance). We conclude that visual cues are very important in all cases. Visual motion cues mainly seem to control the imbalance on landing, whereas visual orientation cues (the only ones to be available in strobe lighting) are used in the backward somersault to estimate the orientation of the body. In the case of a more complex leap (full backward twisting), visual orientation cues are less easily used, and probably replaced by vestibular equivalent cues.