Abstract des Autors

To appreciate the respective role of exteroceptive and proprioceptive afferences in balance control, we developed a non invasive test based on manipulation of the support texture, without direct action on the subject tested. Balance control was appreciated with a craniocorpograph, allowing a photo-optical analysis of the movements of the head and shoulders, viewed from above the subject. Thirty subjects, between 18 and 40 years old (mean: 23 years old), performed on spot stepping, blindfolded, successively on hard and soft foam support. In the latter condition, there was less linear displacement, but lateral oscillations, angular deviation and body rotation were more marked. For the last two parameters, deviations appeared more clearly in the last part of the recording. These data suggest that representation of the posture assumed before the test only falters after some time, and is more affected when somatosensory information is unusual and disturbing. These observations confirm in the absence of visual afferences that vestibular and proprioceptive systems do not completely compensate for perturbations applied to the plantar exteroceptive input, since walking biomechanics are also affected, thus justifying balance training in such conditions to improve this compensation. Verf.-Referat