Highest ambulatory speed using Lokomat gait training for individuals with a motor-complete spinal cord injury: a clinical pilot study
Abstract
Motor impairment and loss of ambulatory function are major consequences of spinal cord injury (SCI). Earlier studies have already shown that robotic gait orthoses (e.g., the Lokomat, which is a mechanically assisted, body weight-supported, treadmill-based gait training device) can improve the walking capacity of a person with SCI.
Lokomat gait training can be used for people who have some degree of ambulatory capacity as well as in patients with no remaining ambulatory function. Recently, there has been a new development in the area of ambulatory function retrieval in people with SCI: the overground exoskeleton.
This robotic device allows people with SCI with no or limited remaining ambulatory function to walk. Various kinds of exoskeletons have been developed; some are even designed to be used at home and throughout the community.
Examples of exoskeletons are the ReWalk (ReWalk Robotics, Israel), the Ekso (Ekso Bionics, USA), and the Indego (Parker Hannifin Corporation, USA). Most of the current exoskeletons are not designed to maintain postural control or balance; therefore, people ambulating in an exoskeleton must use their upper extremities and crutches or a walking frame to support themselves.
An exception is the REX exoskeleton from REX Bionics, which uses linear actuators to provide user stability and balance. A survey of the literature shows that the mean walking speed of persons with a complete SCI in an exoskeleton is 0.26 m/s.
Contrary to exoskeletons, Lokomat gait training is not limited by balance issues or speed limitations: it can reach a maximum speed of 0.9 m/s. A Lokomat is a gait training device that comprises a treadmill belt, a weight support system, and a driven gait orthosis for both legs.
The legs of the person are secured with cuffs to the orthosis. The Lokomat system is adjustable to achieve the best possible fit for each individual.
Using the Lokomat instead of an exoskeleton also eliminates other speed-related factors, such as balance issues. In this clinical pilot study, our aim is to investigate the highest ambulatory speed that people with SCI can safely achieve in a Lokomat.
Additionally, this ambulatory speed is compared with the walking speed of 0.59 m/s, which is required for elimination of wheelchairs, and compared with ambulatory speeds of current exoskeletons.