Children who had difficulty controlling their bodies from birth stood up on their own for the first time. It was thanks to wearing robots on their knees and doing rehabilitation training. Robots to help children walk existed before, but the machines only provided force and did not develop muscles as this one did.
Yanggang Feng of the Department of Mechanical Engineering at Beihang University in China said on the 21st that the team "developed a wearable robot that promotes neuromuscular recovery in children with spinal muscular atrophy (SMA)." According to the researchers, the rehabilitation effect persisted even after stopping the training with the robot. It did not just boost motor function in the short term; it showed the possibility of sustained recovery.
◇ Stand up independently after 6 weeks of rehabilitation training
Spinal muscular atrophy is a degenerative neurological disease in which damage to motor neurons causes muscle atrophy. It is a genetic disorder caused by a mutation in the SMN1 gene and occurs in about 1 in 10,000 newborns. Over the past 10 years, treatments that administer drugs to activate the problematic gene or edit the gene itself have been developed, halting or greatly delaying the loss of nerve cells. But they could not restore muscles that had already atrophied.
The researchers developed a wearable robot to assist isokinetic rehabilitation training. Isokinetic training is a method that extends the knee at a constant angle over a set time. If a patient exerts strong force, the knee-mounted robot increases resistance accordingly to prevent moving too fast. Conversely, if the force is weak, it lowers resistance to match the angular velocity. This helps patients continuously maintain stronger muscle force on their own.
Robot rehabilitation training was conducted on six patients ages 6 to 10 who could not stand up from a seated position without help. The children received training to move their legs more than 60 times, five times a week for six weeks. The training was gamified to raise participation. When the children extended their legs, they could see themselves kicking a ball on a monitor. After completing the training, all the children could stand up from a seated position without the robot.
Video analysis showed the volume of the quadriceps, the thigh muscle, increased by 19%. Rehabilitation training strengthened their muscles enough to stand up. The children could exert more than twice the force when bending their knees. The initial angle needed to stand up from a seated position decreased from 111 degrees to 104 degrees. In other words, they could stand up from a lower posture.
In particular, the rehabilitation effect lasted for a long time. Later, the children performed low-intensity isokinetic rehabilitation training using the robot three times a week for six weeks and then returned to conventional physical therapy. A 30-day follow-up showed the rehabilitation effect persisted even after stopping the robot training.
Feng said, "Temporarily using a wearable robot suggests that long-term neuromuscular recovery can be promoted." Tony Shu of the Massachusetts Institute of Technology (MIT) Media Lab, a co-corresponding author of the paper, said, "According to parents, it became much easier for children at home to roll over and get up from bed or try to move their bodies into certain postures."
◇ Unlike existing robots, delivers fundamental therapeutic effects
Patients with spinal muscular atrophy had also received isokinetic rehabilitation training before. However, such rehabilitation training was only possible at medical institutions with specialized equipment. The devices themselves were bulky and difficult for children to use. The researchers said the knee-mounted robot weighs 0.96 kg, so it does not burden the wearer.
There were also robots for patients with spinal muscular atrophy before. The Spanish National Research Council (CSIC) and its spinoff Marsi Bionics developed the first pediatric exoskeleton robot in 2016. The exoskeleton is a gait-assist device that wraps around the legs. It secures the child's body with aluminum and titanium materials. It weighs just under 12 kg.
When a child tries to walk, sensors in the exoskeleton robot detect muscle signals and activate motors at the joints accordingly. In other words, the robot's legs move as the child intends. Thanks to the robot, a 5-year-old patient with spinal muscular atrophy was able to walk for the first time since birth. However, the exoskeleton robot only assists the act of walking and does not build muscle. It is not a fundamental treatment. By contrast, the knee-mounted robot in this study promoted motor signal transmission and built muscle.
However, this study did not compare against a control group of patients who received rehabilitation training by methods other than the robot, limiting any definitive claim that the robot produced the rehabilitation effect. Families were reluctant to participate if they could not use the robot. The researchers said that with investor support, the wearable robot could be developed as a complementary tool to gene therapy for spinal muscular atrophy. They also expected the same approach could be applied to training other joints and muscles.
References
Nature (2026), DOI: https://doi.org/10.1038/s41586-026-10642-0
CSIC (2016), https://www.eurekalert.org/news-releases/521825