While they’ve long been the stuff of sci-fi flicks — from Aliens and Avatar to Iron Man and Robocop, just to name a few — exoskeletons are increasingly prevalent in the real world. And they serve especially well in two areas: strokes and aging. According to the Centers for Disease Control and Prevention (CDC), someone in the United States has a stroke about every 40 seconds. And about 87% of these strokes are ischemic, with blood flow to the brain reduced or stopped, which in many instances leads to a loss of motor functions. In these instances, upper extremity exoskeletons can be life-changing devices.

Aging is often accompanied by a decrease in muscle strength and control; more than 55 million Americans are aged 65 or older, making them one of the country’s largest (and fastest-growing) cohorts. Both upper and lower body exoskeletons can serve here as well. A range of exoskeletons can also aid people with issues including spinal cord injuries, traumatic brain injuries, and cerebrovascular diseases, offering renewed mobility and independence that were once only dreamed of. And the U.S. Food and Drug Administration (FDA) has taken note, giving clearance to exoskeleton devices including the ReWalk, the Ekso, the Indego, and the Keeogo. As well as the HAL (no relation to the AI villain in the movie 2001: A Space Odyssey) from the Japanese robotics company Cyberdyne (no relation to the AI villain in the movie The Terminator).

How does the HAL work? Short for Hybrid Assistive Limb, the HAL — which Cyberdyne has dubbed a “Wearable Cyborg” — is a lower body exoskeleton that uses bioelectrical signals from the wearer’s brain to prompt the device’s movements. When someone tries to move, the brain sends a signal to the intended muscle to make the movement happen. While faint, these bioelectrical signals are detectable on the skin, and so HAL’s skin-attached sensors intercept the signals to determine the desired movement of the wearer. That information is transferred to a robotic joint, which moves in the direction that the wearer intends. Essentially, the user’s nervous system is the control mechanism.

The HAL exoskeleton recently received approval for 2 new treatments in its home country, bringing its total of allowed uses to 10 types of neuromuscular diseases. The device can now be used in Japan to treat HTLV-1-related myelopathy — a chronic spinal cord disease that debilitates legs — and hereditary spastic paraplegia: an inherited disorder marked by progressive weakening of the legs. While this broader use of the HAL is largely limited to clinics and medical centers in Japan, the expansion can be seen as a sign of a world to come in which such complex exoskeletons are more commonplace outside of clinical settings. Cyberdyne is currently looking for ways to get insurance companies to cover the HAL’s costs. And so one day in the near future, avatars, iron men, and robo-cops may not just be limited to the silver screen.