Robotic Leg Advancement Device

A novel robotic device for automation of a physical therapy for gait patients

Institute Reference: INV-14007


A commonly used gait training paradigm relies on manual leg advancement, where the Physical Therapists (PTs) help patients take their legs through the proper motion during ambulation over a treadmill, or over ground. Such manual therapy often requires 2 or 3 PTs to work together, which carries a high labor cost burden because insurance reimburses for the time of one PT working with one patient, therefore the cost of any extra help from other PTs is absorbed by the hospital. Because of the high cost associated with gait training, many facilities limit the amount of gait training they perform, and as a result, of the 4 million stroke survivors living in the U.S., over 1 million have balance and gait impairments, and over 30% require assistance with gait. 

Advancements in robot-assisted rehabilitation for partially automating such therapy are provided by this invention based on the use of an end-effector design. 

Technology Overview

This invention relates to a novel robotic device for automation of a physical therapy for gait patients, enabling proper movement of their legs during ambulation, overcoming most prior-art limitations and/or unmet needs. Body Weight Support (BWS) systems (frames) are used at rehabilitation hospitals and clinics for gait training of patient populations with motor control related disabilities, such as spinal cord injury (SCI), stroke, chronic pain, head injury, orthopedic problems, cerebral palsy and multiple sclerosis. 

The device uses Joint actuators to automate leg advancement through end-effectors. The Robotic Leg Advancement Device is an accessory, which mounts onto a body weight support frame and attaches to the legs of the patient. Two manipulators apply forces to leg braces to guide the patient’s shank and promote proper gait pattern during gait training. Built-in compliance at the ankle joint will permit limited rotation of the shank/foot with respect to the yokes. The invention includes a base support frame and upper flexion actuation assembly movably coupled to the base support frame. 


  • Administration of training over-ground as opposed to over-treadmill provides preferred modality for training
  • Assists physical therapists in administering gait training, thus obviating the need for additional resources
  • Retrofits for use with the majority of BWS systems and walkers. 


  • Physical therapy
  • Gait training
  • Rehabilitation


  • Licensing
  • Partnering
  • Research Partner



  • Development partner
  • Commercial partner
  • Licensing

IP Status

  • Patented


Patent Information:
Medical Devices
For Information, Contact:
Dormant Physical
Northeastern University
Maciej Pietrusinski
Constantinos Mavroidis (bei)
Medical Device