Towards Precision Robotics: Matching individualized walking deficits with characteristics of lower extremity robotic devices

Towards Precision Robotics: Matching individualized walking deficits with characteristics of lower extremity robotic devices

Matching individualized walking deficits with characteristics of lower extremity robotic devices

In the previous newsletter, we introduced the notion that the field of rehabilitation robotics must consider how to better align the perspectives and interests of three groups: device developers, rehabilitation researchers, and the clinician/patient dyad. We also posed several questions about this topic. If you have not yet done so, we encourage you to first review “A Shared Perspective: A Framework for aligning the Perspectives of device developers, rehabilitation researchers and Clinicians and consider those questions.

In attempting to find a common framework with which to bring together the perspectives and interests of the various stakeholders in rehabilitation, we will start with consideration of the individual patient. The rehabilitation enterprise has increasingly recognized the importance of patient-centred care over the past decade, acknowledging that all of the efforts within rehabilitation are devoted towards the patient. Here, we specifically consider the case of rehabilitation technology efforts directed towards improving walking ability. Although the individual patient to whom the rehabilitation efforts will be applied is the endpoint of this process, we recognize that it is the clinician who will apply the rehabilitation process, and has the expertise outlined below. We continue to focus on the clinician/patient dyad, but with most emphasis below placed on the role of the clinician.
Identification of “aspects of walking”
In deciding how to address walking dysfunction, the clinician must first consider the question, “In what way do I want to improve the walking ability for this particular individual?” Here, the clinician is challenged to identify something about the patient’s walking ability that is desired to be changed. Through consideration of the basic functions of the act of walking, specific aspects of walking can be identified that will provide a focus for the efforts of the clinician. What are the basic functions of walking that must occur for walking to be successful? Although these have not been definitively identified and agreed upon, the following list serves as a starting point for consideration:
  • Knee Stance Stability
  • Trunk Upright
  • Limb Advancement
  • Dynamic Balance

Importantly, these are not considered as “predecessors” to walking, but rather as components of the act of walking, needing to be considered and assessed within the act of walking.

The identification of this limited set of critical aspects of walking allows us to introduce our framework and illustrate how these aspects of walking are used to inform the process throughout.

A focus on practice of walking

Once a clinician has identified a deficit in one or more of the above aspects of walking, they can now direct their treatment efforts towards addressing the particular deficit(s). In doing so, we must first recognize that the only way to directly improve walking ability is to practice walking.

This is a simple but powerful statement. We recognize that walking ability may be indirectly affected if we provide treatments focusing on impairments such as deficits in strength or range of motion, and this may sometimes be appropriate. Although we could also plan to focus on “pre-gait” activities such as standing tolerance, weight shifting, or isolated stepping, we have increasing evidence that focus on these simpler tasks do not lead to significant changes in walking ability. Instead, we recognize that practicing walking is the direct way to focus on improving the skilled task of walking. But, how do we practice walking? Will walking practice occur in the same way for different patients? How does the clinician decide to structure the walking practice differently for different patients with different deficits in walking abilities? While previously this piece of clinical reasoning was not elucidated, we can now use our above focus on aspects of walking, along with recognized principles from motor learning and neuroplasticity, to provide an explicitly identified, structured framework for consideration.

Walking practice should include an appropriate level of challenge to the aspect(s) of walking being addressed.

If, for example, the clinician identifies that limb advancement needs to be improved, then walking practice should occur that provides an appropriate level of challenge to limb advancement. In addition to this primary focus provided for the walking practice, Box 1 below provides additional important principles to be followed to help identify the appropriate structure for the walking practice for each individual patient.

These principles provide guidance to the clinician whose job is to structure the walking practice, but importantly, also help to provide structure to the framework through which we consider the roles of our other groups, device developers and rehabilitation researchers.

Box 1. Principles to structure walking practice.

Walking practice should include an appropriate level of challenge to the particular aspect(s) of walking being addressed.

Feedback to the patient regarding their performance on the aspect of walking being focused upon is critical. This feedback can be either extrinsic (externally provided) or intrinsic.

Different aspects of walking can be focused upon with different bouts of walking practice. 

The dosage of walking practice needs to be considered. The more, the better! 

The intensity of walking practice needs to be considered. The patient needs to be working hard and maximally engaged in the walking practice.

Rehabilitation technology and robotics provide ingredients to be used to structure walking practice.

Hopefully, we have come to understand that a particular rehabilitation device is not “a treatment”, but a tool to be used by the clinician in their rehabilitation efforts. Through the principles identified above, we can now better understand how devices can be considered in relation to the principles of walking practice discussed above. Rather than considering devices to be treatments themselves, or even for the device to be a single ingredient to be used in structuring walking practice, we consider that relevant characteristics of devices are considered as ingredients in walking practice.

What might these “relevant characteristics” look like? To begin, we consider the identified aspects of walkingand how a particular device can be used to titrate – either increase or decrease – the level of challenge for that particular aspect as a key ingredient that device provides for the walking practice. Additionally, through consideration of our other principles to structure walking practice, provided in Box 1, we can identify additional relevant characteristics of devices. These are provided below, in Box 2.

Box 2. Relevant characteristics of devices as ingredients of walking practice.

  • Increase / decrease challenge to knee stance stability
  • Increase / decrease challenge to trunk upright
  • Increase / decrease challenge to limb advancement
  • Increase / decrease challenge to dynamic balance
  • Provision of external feedback for knee stance stability
  • Provision of external feedback for trunk upright
  • Provision of external feedback for limb advancement
  • Provision of external feedback for dynamic balance
  • Facilitation of increased dosage of walking practice
  • Facilitation of increased intensity / engagement of walking practice
Figure 2. The identified relationships among the three groups discussed.



Physical Therapist, Neurology Certified Specialist

Andrew Packel is a board-certified specialist in neurologic physical therapy with extensive experience working with stroke and traumatic brain injury patients. He currently works at MossRehab and has a particular interest in optimizing interventions to improve walking, including the use of robotics and technology. He has been involved in many research projects and publications and has given presentations on these topics.


Executive Director, MotusAcademy
Incoming President, IISART
Co-Founder & Global CEO, Fourier Intelligence

Zen is a visionary and pioneering influencer in the field of MedTech and Robotics for Rehabilitation. He has been involved in several successful start-ups and businesses in Singapore, Switzerland, and China for over two decades, providing medical devices, healthcare solutions, and services for people with disabilities and neurological patients. He was nominated as one of the 40 under 40 most influential industry leaders in MedTech in 2012.

Zen holds multiple leadership roles, including the incoming president and ambassador of the International Industry Society for Advanced Rehabilitation Technology (IISART), General Chair for RehabWeek 2023, co-founder and Executive Director of the Swiss-based MotusAcademy Association, Managing Editor of the Journal of Rehabilitation Methods and Technologies (JRMT), and co-founder and Global CEO of Fourier Intelligence Group. Under his leadership, Fourier has raised over USD100 million, notably in 2022, from renowned investors such as Saudi Aramco Prosperity 7 venture and Softbank Vision Fund 2.

Leave a Reply