Wearable knee robot could help children with muscle weakness

Publicly released:
International
Photo by Towfiqu Barbhuiya on Unsplash
Photo by Towfiqu Barbhuiya on Unsplash

Researchers have developed a lightweight wearable robotic knee device designed to help children with spinal muscular atrophy build muscle strength and improve movement. In a clinical trial involving six children who could not stand up from a seated position without help, all of them were able to stand independently after six weeks of training with the device. The researchers also noted improvements in muscle size and knee function, with benefits continuing after the training ended. The team says the device could help expand rehabilitation options for children with neuromuscular conditions.

News release

From: Springer Nature

Wearable robotic device facilitates neuromuscular recovery in children

A lightweight robotic device that facilitates neuromuscular recovery in children with spinal muscular atrophy (SMA), helping them to stand unassisted, is described in Nature this week. Improved function persists after discontinuing training, demonstrating the potential for enduring recovery.

SMA is a neuromuscular disorder that affects the nerves and causes muscle weakness, which can limit movement in affected individuals. Symptoms can be managed with physiotherapy, such as isokinetic resistance training, which uses speed-controlled exercises to improve strength. However, such training requires equipment that is only available at specialist institutions, and the devices used for this training are often too bulky and difficult for children to use.

Yanggang Feng and colleagues designed a lightweight (0.96 kg) wearable knee robot to assist isokinetic training for children with SMA type II, an intermediate form of the condition. In a clinical trial, they tested outcomes in six children (aged 6–10 years old) who could not stand from a seated position without assistance.

After six weeks of training with the device, using it five times a week, the authors observed improvements in movement (all six children were able to stand from a seated position without the help of the robot), knee function, and muscle volume (the quadriceps increased by 19%). The children continued with a further six weeks of low-intensity isokinetic training (using the device three times per week) and then returned to conventional physiotherapy and were followed up for 30 days.

The participants maintained the gains in function after discontinuing isokinetic training, indicating that temporary exposure to the wearable isokinetic training robot device can facilitate prolonged neuromuscular recovery.

Future trials with larger cohorts are needed to accurately determine the efficiency of this treatment, although recruitment was limited because SMA is a rare disease with poor outcomes, the authors note. They add that further modifications that target different muscles may improve the potential of the device.

Multimedia

Overview
Overview
SMA Pathophysiology
SMA Pathophysiology
Gain of sit-to-stand function
Gain of sit-to-stand function
Assistive versus resistive
Assistive versus resistive
Wearable knee robot

Attachments

Note: Not all attachments are visible to the general public. Research URLs will go live after the embargo ends.

Research Springer Nature, Web page
Journal/
conference:
Nature
Research:Paper
Organisation/s: Beihang University - China
Funder: This work was funded primarily by Yanggang Feng, alongside modest financial assistance from the Fundamental Research Funds for the Central Universities (JKF-20240243, JKF-2025044308227).
Media Contact/s
Contact details are only visible to registered journalists.