Article

Idiopathic scoliosis is the most frequent spinal deformity in adolescence. While
its aetiology remains unclear, impairments in balance control suggest a
dysfunction of the sensorimotor control mechanisms.
The objective of this paper
is to evaluate the ability of patients with idiopathic scoliosis to reweigh
sensory information. Using a neuromechanical model, the relative sensory
weighting of vestibular and proprioceptive information was assessed. Sixteen
healthy adolescents and respectively 20 and 16 adolescents with mild or severe
scoliosis were recruited. Binaural bipolar galvanic vestibular stimulation was
delivered to elicit postural movement along the coronal plane. The kinematics of
the upper body, using normalized horizontal displacement of the 7th cervical
vertebra, was recorded 1s before, 2s during, and 1s following vestibular
stimulation. The neuromechanical model included active feedback mechanisms that
generated corrective torque from the vestibular and proprioceptive error signals.
The model successfully predicted the normalized horizontal displacement of the
7th cervical vertebra. All groups showed similar balance control before
vestibular stimulation; however, the amplitude (i.e., peak horizontal
displacement) of the body sway during and immediately following vestibular
stimulation was approximately 3 times larger in patients compared to control
adolescents. The outcome of the model revealed that patients assigned a larger
weight to vestibular information compared to controls; vestibular weight was
6.03% for controls, whereas it was 13.09% and 13.26% for the mild and severe
scoliosis groups, respectively. These results suggest that despite the amplitude
of spine deformation, the sensory reweighting mechanism is altered similarly in
adolescent patients with scoliosis.
CI - Copyright (c) 2015 Elsevier B.V. All rights reserved.

Langue : ANGLAIS