Estratégias de controle postural em indivíduos com lesão medular

Abstract

Introduction: The balance control involves the joint action of sensory and motor systems, coordinated by the Central Nervous System. The wheelchair users interact with the environment from a sitting position, different from walking individuals, which requires them different postural control strategies these. This difference shows the need for more detailed information about the balance of wheelchair users, especially of injured spinal cord in order to understand the action of the postural control system and contribute to the performance of activities of daily living and sports tasks these individuals. Objective: To analyze the functioning of postural control in injured spinal cord sitting on different surfaces. Methods: 19 subjects (10 healthy and nine injured spinal cord) underwent balance assessments sitting on a force platform on three conditions: sitting in a wheelchair, on a wooden bench and on the surface of the platform itself in Buddha position. During testing, by surface electromyography, they were accompanied muscle activity of the pectoralis major, serratus anterior, rectus abdominis, upper trapezius, lower trapezius, erector spinal the height of L1 and T9 and latissimus dorsi. Results: There were significant differences between the groups mainly in the wheelchair condition. Time variables showed major displacement of the center of pressure in cord injury individuals than in healthy individuals. Frequency variables showed higher percentages in the lower frequency bands in the injured group, indicating greater use of sensory systems (visual and vestibular) as the main postural control strategy on the part of these individuals. In addition, there was a greater muscle activation of the serratus anterior and latissimus dorsi muscles in the injured spinal cord in the wheelchair condition and lower activation spinal erector L1 in bank condition. Conclusion: The findings of this study suggest that individuals with spinal cord injury use different postural control strategies in relation walking individuals, using sensory systems and other muscle synergies to compensate losses of other systems and muscles involved in postural control.