To successfully integrate a neural interface into one’s daily routine, akin to adapting to a prosthetic, requires a deliberate and methodical approach, comprising two distinct stages. First, sufferers endure surgical procedure. After a lower limb amputation, residual portions of shin and calf muscle often remain. The gastrocnemius and soleus muscles of the calf are connected to the tibialis anterior muscle in the shin, enabling the ankle to flex upwards while the calf muscles resist this movement. The prosthetic device will be carefully fitted and secured at this precise level to ensure optimal functionality. By reattaching and rehabilitating the residual muscles, the prosthetic can exhibit enhanced agility and movement capabilities. Additionally, it has been shown to effectively reduce phantom limb pain, resulting in fewer falls and injuries for affected individuals.
“The pioneering surgery was a game-changer for me,” remarks Amy Pietrafitta, a trailblazing para-athlete who underwent the groundbreaking procedure in 2018. Despite the prosthetic’s advancements, true control remains elusive as long as it’s not connected to the nervous system, leaving even the most dedicated users feeling frustratedly stuck in a cycle of limited mobility: “I really feel like I’ve got my leg back.”
During the second stage, floor electrodes detect neural activity from the brain to the calf and shin muscle groups, suggesting an intention to move the lower leg. Within a prosthetic leg, a miniature computer translates neural signals into precise movements, allowing individuals with mobility impairments to control their artificial limbs with greater ease and dexterity.
You likely possess fully functioning organic appendages, effortlessly navigating stairs or walking up and down steps without ever giving it a second thought. It’s involuntary,” says Herr. “That’s the case with our patients whose prosthetic limbs are made from a combination of titanium and silicone.”
Researchers compared the mobility levels of seven patients equipped with a neural interface to those of individuals who had not undergone the surgery. Individuals using a neural interface experience a significant boost in mobility, with walking speeds increasing by 41%, enabling them to tackle steeper inclines and navigate stairs with greater ease. They might also navigate obstacles with increased agility and possess greater equilibrium. For many amputees, the prosthetic becomes an integral part of their body, rather than just a tool they use to navigate daily life.
