Equilibrium of Humans Trained by Balanceboard and Exercises

Abstract

The mechanism of the development of equilibrium skills was studied in subjects standing on a balance-board, somersaulting during gymnastic exercises and performing ballet rotations.
1. The ability to stand steadily on a freely movable balance-board was achieved after several days practice. The records of sways of the head and center of gravity of the body and activities of the nuchal and soleus muscles indicat that maintenance of a steady standing posture was possible because labyrinthine and proprioceptive postural regulations became precise. The training effect was due to facilitation of the postural reflexes through the brainstem and spinal cord.
2. A somersault requires a chain of postural reflexes : visual fixation, labyrinthine righting reflex upon the head, and tonic neck reflex. We conclude that the basal ganglia and cerebellum play important roles in the formation of this chain of postural reflexes.
3. Eye and head movements during ballet rotation with spotting technique were studied using a telemeter in a beginner and a trained dancer. During the trained subject's rotation, eye movements induced by optokinetic and la-byrinthine-ocular reflexes appeared to be under voluntary control. The ballet rotation was a movement that postural reflexes were inserted into a chain of voluntary movements carried out by a central program formed by training. The cereberal cortex was involved in this central programming. In the functional development of body equilibrium by training, the degree of participation of the central nervous system varied depending on kinds of exercises trained : the cerebral level in ballet rotation, the basal ganglia and cerebellum level in somersaults, and the brainstem and spinal cord level in standing posture.