Article

Neuroprostheses can restore functions such as hand grasp or standing
to individuals with spinal cord injury (SCI) using electrical stimulation to
elicit movements in paralyzed muscles. Implanted neuroprostheses currently use
electromyographic (EMG) activity from muscles above the lesion that remain under
volitional control as a command input. Systems in development use a networked
approach and will allow for restoration of multiple functions but will require
additional command signals to control the system, especially in individuals with
high-level tetraplegia. OBJECTIVE: The objective of this study was to investigate
the feasibility of using muscles innervated below the injury level as command
sources for a neuroprosthesis. Recent anatomical and physiological studies have
demonstrated the presence of intact axons across the lesion, even in those
diagnosed with a clinically complete SCI; hence, EMG activity may be present in
muscles with no sign of movement. METHODS: Twelve participants with motor
complete SCI were enrolled and EMG was recorded with surface electrodes from 8
muscles below the knee in each leg. RESULTS: Significant activity was evident in
89% of the 192 muscles studied during attempted movements of the foot and lower
limb. At least 2 muscles from each participant were identified as potential
command signals for a neuroprosthesis based on 2-state, threshold classification.
CONCLUSIONS: Results suggest that voluntary activity is present and recordable in
below lesion muscles even after clinically complete SCI.

Langue : ANGLAIS