Highlights
– UCLA investigators used intramuscular wire EMG and high-speed motion capture to show that the orbicularis oculi executes segmental, task-specific activation patterns rather than a unitary up–down contraction.
– Five eyelid closure behaviors (spontaneous, voluntary, reflexive, soft closure, forced closure) differ in onset timing, spatial recruitment within the muscle, and kinematic trajectory.
– The findings provide practical guidance for electrode placement, timing strategies, and stimulation design for future blink-assisting neuroprostheses aimed at preventing exposure keratopathy in patients with eyelid paralysis.