[Agonist-antagonist myoneural interface (AMI) : Innovative treatment option for lower limb amputees?]

Abstract

The agonist-antagonist myoneural interface (AMI) is an innovative approach to restoring proprioception and achieving more intuitive motor control following limb loss. This cutting-edge technique replicates the natural biomechanical relationship between agonist and antagonist muscles, enabling bidirectional communication between a prosthesis and the user's peripheral nervous system. Through the transposition of neurovascularly pedicled agonist-antagonist muscle pairs, which are reconnected via an adapted tendon suture and positioned within a gliding mechanism, AMI generates proprioceptive feedback during movement. Changes in tension within these muscle pairs produce signals that are transmitted to the central nervous system via afferent nerve pathways, enabling users to perceive the joint position of the limb that was originally governed by the muscle pair. This enhanced sensory input significantly facilitates control of the prosthesis. The AMI appears to enable an integration of the prosthesis into the body's existing neural networks and improve motor control of the prosthesis and the sensory discrimination. Compared to traditional surgical techniques (myodesis or myoplasty) with a purely mechanical transposition of residual stump muscles, AMI reduces the cognitive burden during the use of the prosthesis and delivers a more natural sense of movement, fostering a profound sense of embodiment. In summary, AMI represents a significant leap forward in human-machine integration. By enhancing both the functionality and user experience of prosthetic devices, it provides a very promising transformative solution for sustainable improvement of the quality of life for individuals living with limb loss.