BEIJING -- In a clinical trial, six kids who were losing their motor skills are defying the odds by using a wearable robot that weighs only 0.96 kilograms to learn how to stand up on their own.

With help from the portable device developed by China's Beihang University in collaboration with MIT and Peking University Third Hospital, these children who had trouble standing on their own went from sitting to standing after six weeks of resistance training.

Unlike traditional wearable rehabilitation robots that provide "assistance" to complete movements, this robotic device takes a counterintuitive approach. It applies controlled "resistance," forcing the joints to move at a constant speed. This mechanism safely compels the muscles to generate maximum tension, driving physiological growth rather than relying on mechanical aid.

Composed of a back-drivable damping motor and a variable stiffness mechanism, the device enforces constant angular velocity during leg extension, providing a level of stimulation that traditional low-intensity training simply cannot match.

The team enrolled three boys and three girls aged 6 to 10 with Spinal Muscular Atrophy (SMA) type II in a 5.5?month trial: a 6?week observation period, followed by six weeks of high?intensity training (five sessions per week), then six weeks of low?intensity maintenance (three sessions per week), and finally more than 30 days of robot?free follow?up.

The team also developed a gamified mobile interface that rewards harder kicks with a cartoon character kicking a ball farther across the screen, thus boosting engagement.

SMA is a rare genetic disease caused by the mutation in a gene that encodes a protein critical for the maintenance and function of motor neurons. Motor neurons in the brain and spinal cord control muscle movement throughout the body and a lack of them can lead to fatal muscle weakness.

After six weeks of high?intensity training, all participants showed encouraging signs of improvement. They gained the ability to perform sit?to?stand transitions with hands on knees and no external support. Bilateral peak knee torque increased by 130 percent on average, range of motion by 51 percent, and muscle volume by 19 percent.

Moreover, they maintained these gains after discontinuing robot training and returning to conventional physiotherapy, with all functional, morphological and neurophysiological improvements remaining stable throughout the subsequent trial phases.

These results suggest that even temporary exposure to isokinetic resistance training through wearable robotics may facilitate enduring neuromuscular recovery, according to the researchers.

This breakthrough was featured on the homepage of the journal Nature last week.