When a person attempts to move, nerve signals are sent from the brain to the muscles via motoneuron, moving the musculoskeletal system as a consequence. At this moment, very weak biosignals can be detected on the surface of the skin. HAL catches these signals through a sensor attached on the skin of the wearer. Based on the signals obtained, the power unit is controlled to wearer’s daily activities.
quote: "At the moment, there really isn't anything out there that alters myostatin levels other than exercise," Wells said. "It costs energy to keep the muscle alive; the body is very nicely tuned, so if you don't need the muscle, you lose it." Since Liam's muscles don't see the effect of myostatin, he has a monstrous appetite. "He's hungry for a full meal about every hour because of his rapid metabolism," Dana Hoekstra told the AP. "He's already eating me out of house and home."