Researchers used a soft, wearable robot to help a Parkinson’s patient walk without freezing. The robotic garment, placed around the hips and thighs, provides a mild push to the hips when the leg swings, allowing the patient to take longer strides. The gadget eradicated the participant’s freezing when walking indoors, allowing them to go faster and farther than they could without the garment’s assistance.
Freezing is one of the most prevalent and debilitating symptoms of Parkinson’s disease, a neurological condition that affects over 9 million people worldwide. When people with Parkinson’s disease freeze, they lose the ability to move their feet abruptly, typically in the middle of a stride, resulting in a series of staccato stutter steps that are progressively shorter until the person stops completely. These episodes are one of the biggest contributors to falls among people living with Parkinson’s disease.
Today, freezing is treated with a range of pharmacological, surgical, or behavioral therapies, none of which are particularly effective.
Our study participants who volunteer their time are real partners. Because mobility is difficult, it was a real challenge for this individual to even come into the lab, but we benefited so much from his perspective and feedback.
Conor Walsh
What if there was a way to stop freezing altogether?
Researchers from Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS) and Boston University’s Sargent College of Health & Rehabilitation Sciences employed a soft, wearable robot to help a Parkinson’s patient walk without freezing. The robotic garment, placed around the hips and thighs, provides a mild push to the hips when the leg swings, allowing the patient to take longer strides.
The gadget totally eradicated the participant’s freezing when walking indoors, allowing them to go faster and farther than they could without the garment’s assistance.
“We found that just a small amount of mechanical assistance from our soft robotic apparel delivered instantaneous effects and consistently improved walking across a range of conditions for the individual in our study,” said Conor Walsh, the Paul A. Maeder Professor of Engineering and Applied Sciences at SEAS and co-corresponding author of the study.
The research demonstrates the potential of soft robotics to treat this frustrating and potentially dangerous symptom of Parkinson’s disease and could allow people living with the disease to regain not only their mobility but their independence.
The research is published in Nature Medicine.
For over a decade, Walsh’s Biodesign Lab at SEAS has been developing assistive and rehabilitative robotic technologies to improve mobility for individuals post-stroke and those living with ALS or other diseases that impact mobility. Some of that technology, specifically an exosuit for post-stroke gait retraining, received support from the Wyss Institute for Biologically Inspired Engineering and was licensed and commercialized by ReWalk Robotics.
In 2022, SEAS and Sargent College received a grant from the Massachusetts Technology Collaborative to support the development and translation of next-generation robotics and wearable technologies. The research is centered at the Move Lab, whose mission is to support advances in human performance enhancement with the collaborative space, funding, R&D infrastructure, and experience necessary to turn promising research into mature technologies that can be translated through collaboration with industry partners.
This research emerged from that partnership.
“Leveraging soft wearable robots to prevent freezing of gait in patients with Parkinson’s required a collaboration between engineers, rehabilitation scientists, physical therapists, biomechanists and apparel designers,” said Walsh, whose team collaborated closely with that of Terry Ellis, Professor and Physical Therapy Department Chair and Director of the Center for Neurorehabilitation at Boston University.
The team spent six months working with a 73-year-old man with Parkinson’s disease, who — despite using both surgical and pharmacologic treatments — endured substantial and incapacitating freezing episodes more than 10 times a day, causing him to fall frequently. These episodes prevented him from walking around his community and forced him to rely on a scooter to get around outside.
In previous research, Walsh and his team leveraged human-in-the-loop optimization to demonstrate that a soft, wearable device could be used to augment hip flexion and assist in swinging the leg forward to provide an efficient approach to reduce energy expenditure during walking in healthy individuals.
Here, the researchers used the same approach but to address freezing. The wearable device uses cable-driven actuators and sensors worn around the waist and thighs. Using motion data collected by the sensors, algorithms estimate the phase of the gait and generate assistive forces in tandem with muscle movement.
The effect was instant. Without any particular training, the patient was able to walk without freezing indoors and only had infrequent bouts outside. He was also able to walk and communicate without freezing, which is unusual without the gadget.
“Our team was really excited to see the impact of the technology on the participant’s walking,” said Jinsoo Kim, former PhD student at SEAS and co-lead author of the study.
During the study visits, the participant told researchers: “The suit allows me to take longer steps, and when it is not operating, I realize I drag my feet a lot more. It has truly helped me, and I believe it is a wonderful step forward. It could allow me to walk for extended periods of time while maintaining my quality of life.”
“Our study participants who volunteer their time are real partners,” he added. “Because mobility is difficult, it was a real challenge for this individual to even come into the lab, but we benefited so much from his perspective and feedback.”
The device could also help researchers better understand the processes of gait freezing, which are currently unknown.
“Because we don’t really understand freezing, we don’t really know why this approach works so well,” Ellis said. “However, this study highlights the potential advantages of a ‘bottom-up’ rather than ‘top-down’ approach to treating gait freezing. We observe that restoring almost-normal biomechanics changes the peripheral dynamics of gait and may have an impact on central gait control processing.
