Screen shot of the Vicon Nexus 1.7.1 software showing a motion analysis model of a cross-country skier

How to Choose the Right Gait Analysis Technology for You

My youngest daughter is off to university in the fall. As a graduation gift, and to support her for the next four years of school, I wanted to buy her a new laptop. Unlike me– who studied science and business–she is going to study film, animation, and fine arts, so trying to determine which computer would perform for the specific requirements of her program was perplexing, to say the least.

While comparing specifications of video graphic cards, RAM, and program compatibilities, it occurred to me: this must be how many of my customers feel. I was afraid of making the wrong choice, but how could I effectively differentiate between competitors when most of the comparative information is new to me?

Whether a medical clinic or research lab, for many customers looking to invest in a computerized gait analysis system, this is their first time exploring such technologies. Knowing this, I asked myself: how can I help my customers feel better equipped to make this decision?

So, with this article I want to offer my inside perspective. I’ll share my knowledge about what options are available in the market, what points I think you should ponder when approaching this investment, and which questions to ask when comparing potential suppliers.

Ready to be confident in your decision making? Let’s get started.

Computerized Gait Analysis Options

Motion Capture Cameras

Originally built for the film industry, motion capture cameras are now widely used in university (larger, research facilities) and speciality gait analysis laboratories. This equipment is amazingly sophisticated, offering data rich gait analysis. Motion capture camera systems require the longest set up time. (Not just for set up of the system, but for individual assessments, as they use specifically placed sensors on the patient.) This, coupled with potentially complicated post data processing and time-consuming analysis, they are not common in clinical settings.

Vicon motion camera subject and camera area screen shot (Photo Credit: Rossi et al. 'Wearable haptic anklets for gait and freezing improvement in Parkinson’s disease: a proof-of-concept study')

It is unusual to see customers trying to decide between a camera system and a floor-based system like Stepscan. Often, when I discuss motion capture camera systems, it is because one of these larger labs is looking to compliment their camera system with a product that can measure foot-floor interaction, further enhancing their biomechanical assessment capabilities.

A screen shot of the Vicon Nexus 1.7.1 software showing a motion analysis model of a cross-country skier (Photo Credit: Pohjola, M.V. 'Analyzing Effectiveness of Force Application in Ski Skating Using Force and Motion Capture Data -A Model to Support Cross-Country Skiing Research and Coaching')

It’s important to remember that camera systems and floor-based systems measure different things and are more complimentary than competitive.

Force Plates

Like camera systems, force plates are commonly found in research centres and sophisticated gait labs. The advantages of force plates is that they are very durable and incredibly sensitive instruments. Unfortunately, this sensitivity also means that building and ground vibrations can cause unwanted signal noise. This can be solved with sophisticated installation and mounting requirements designed to minimize vibration of the device, but such installation often requires the assistance of an architect or contractor, significantly increasing costs.

Subject standing on Kistler force plate wearing reflective markers attached to skin to identify body landmarks and 3D motion of body segments (Photo credit: Wikipedia 'Force Platform')

The second potential disadvantage of force plates is that the data provided is limited to the measurement of ground reaction forces (although admittedly with amazing detail and accuracy), which may not be sufficient for some gait assessment applications.

Force Plate Forces and Axes (Photo Credit: Galloy et al. 'Preparing Force Data')

As with the camera systems, I don’t typically meet customers that are deliberating between a force plate or a Stepscan system. Force plates and Stepscan measure different aspects of movement and, as with motion capture camera systems, are more complimentary than competitive. You can find cameras, force plates, and Stepscan systems working together in larger gait analysis facilities.

The prospects I spend most of my time with are owners of private physiotherapy clinics that want to modernize their assessments of walking ability from old school eyeballing to technology-based objective measures.

Instrumented Walkways

When instrumented walkways first came on the market, they were a welcomed tool in the clinical space. Early systems are called spatio-temporal mats because, precisely as it sounds, they measure spatial and temporal parameters of gait. A key part of that to note is that they *only* measure spatial and temporal statistics.

Original instrumented walkways are based on a simple switch technology that identifies the presence or absence of the foot on the mat and measures the timing and distance parameters accordingly. These systems are not capable of measuring plantar pressure or kinetic parameters of gait.

GAITRite walkway system

Fast forward 25 years and floor-based, instrumented walkways have evolved significantly. Modernized walkways, such as Stepscan, offer an abundance of data, including kinetic variables such as vertical force, pressure distribution, centre of pressure, and other critical foot/floor interaction variables. When speaking with customers, I equate buying an old, switch-technology instrumented walkway with buying a black and white camera, as compared to new, plantar pressure/gait walkways which would be similar to a camera capable of capturing colour.

Things to Consider

But there is more to consider than just data needs and convenience when selecting a gait analysis technology.

Allow me to circle back to my computer purchase decision. When choosing a computer for my daughter, I was thankful to have the helpful university staff to send me a list of required specifications. Like a camera or a computer, the technical performance capabilities of computerized gait analysis systems vary widely, and alongside them, so does cost.

So how do you decide what to buy? What is considered ‘good enough’? Where can you go to determine what is recommended or required?

This is why I enthusiastically support the efforts of the International Foot and Ankle Biomechanics Community (iFAB). iFAB aims to improve “understanding of foot and ankle biomechanics as it applies to health”, provide up to date knowledge about foot and ankle biomechanics, and facilitate debate on key issues effecting the community.

iFAB took on the enormous responsibility of surveying an international group of foot and ankle biomechanical experts to develop industry standards for gait and plantar pressure measurement devices– medical equipment being used to inform treatment decisions in weakened and impaired individuals. Their recommendations are described in a peer reviewed journal article, but the highlights are summarized in the table below.

Table of i-FAB-PG Medical PMD Technical Performance Specifications
i-FAB-PG Medical PMD Technical Performance Specifications

Stepscan is proudly the first platform designed and engineered to meet these standards. If you are in the market for a gait measuring platform, I strongly encourage to ask your potential suppliers about how they compare to these recommended standards. If they claim to be unaware of the standards, they very likely do not meet them.

Questions to Ask Potential Vendors

What else should you be asking of potential vendors? When exploring gait analysis technology options, to ensure you are comparing apples to apples, per se, I invite you to ask the following questions:

1. Is your technology registered with the U.S. FDA or Health Canada?

Why is this important to ask? Some technologies have limited performance. Therefore, they do not meet the standards to be registered as medical devices and, as a result, are not suitable for clinical use. Be aware of technologies that are marketed for retail or other consumer markets and specifically asked if the brand is recognized by any relevant health authorities.

 

2. Is your technology a spatial / temporal mat or does it also measure pressure?

Why is this important to ask? Are you buying a black and white camera or a color camera? If your vendor uses terminology like “relative pressure”, they likely do not measure pressure. Ask what unit of pressure they offer measurements in (kPa, Newtons, etc.).

 

3. What is your accuracy and repeatability? How do you measure this?

Why is this important to ask? When investing in a device used to take measurements that will inform treatment decisions, you should be interested in how dependable those measurements are.

 

4. How do you calibrate your sensors?

Why is this important to ask? Some companies only calibrate groups of sensors and apply general offsets across the platform. This impacts the technology’s accuracy and repeatability. Conversely, if each and every sensor is individually calibrated, this ensures maximum accuracy and therefore, reliability.

 

5. Do I have to calibrate my system for every patient?

Why is this important to ask? The response to this question speaks to the quality and stability of measures provided by various technologies. It also allows you to gauge whether a technology will be a good fit for your workflow. Does the system require additional calibration time or are the assessments quick and easy?

 

6. How often do you recommend recalibration?

Why is this important to ask? Poor quality and degrading sensors require frequent recalibration and/or replacement. Some sensor technologies require annual shipment back to the factory to have the sensors replaced. Knowing what type of maintenance commitment each system has is important when choosing what is right for your facility.

 

7. What is the warranty?

Why is this important to ask? This is not just a value-added quality. Each system’s warranty reflects how confident a manufacturer is in the performance and quality of their technology. If a warranty is shorter than other competitors, consider it a red flag.

 

Hopefully this article helps to clarify what you should be looking for in order to choose the right gait analysis technology for you.

If you would like to learn more about Stepscan and whether it would be a good fit for you, reach out to a Product Specialist today.

About Crystal Trevors

Crystal is the founder and owner of Stepscan Technologies Inc. She holds a Bachelor of Science from the University of New Brunswick, a Master of Science in Biology from the University of Prince Edward Island, and a Master in Business Administration from the University of Guelph. Her business and research interests include corporate performance management and reporting, process improvement and operational efficiencies. Operating Stepscan is a dream come true for her, allowing her to combine her love of biology, research and business, every day.

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