PHOTO CAPTION: Observational gait analysis has had a long history with rehabilitation because it is accessible, affordable, and can be performed in nearly any type of space. As gait assessment technologies become smaller and more affordable, however, the possibility of bringing objective measures of gait in-house expands for many clinics.
Technologies for treating post-stroke patients are becoming smaller while the functions they perform are growing larger. This is especially true for advances that are making measurement and assessment systems more portable and affordable, and have equipped them with powerful electronics that provide a data-driven picture of patient performance.
Devices that measure gait are where some of the most significant developments in stroke rehab technologies have occurred. For a very long time, gait measurement has been performed by therapists who use their powers of observation to assess an individual’s gait characteristics. This “observational gait analysis” is accessible and affordable and requires only a therapist’s time and space in the therapy gym. No specialized equipment or training is needed. While the method is expedient and inexpensive, it carries a number of potential pitfalls associated with human error including distraction and therapist bias. Today’s technologies can reduce or remove the potential for those errors.
Among the current technologies that provide a clear and quantifiable assessment of an individual’s gait are mats and walkways that are placed over floors and a variety of other walking surfaces. Patients ambulate on those surfaces while the embedded sensors record data that capture the geometry and relative arrangement of each footfall as a function of time and space. These temporal-spatial measures of gait and pressure enable therapists to objectively measure the effectiveness of interventions and make comparisons against baselines to detect decline or improvement.
Some of the data that gait mats and electronic walkways provide include gait phase, gait cycle, step and stride, velocity, distance, center of pressure (COP), and coefficient of variation. Therapists can use these data for analysis of activities such as forward and backward gait, transitional movements, timed up and go (TUG), jumping and hopping, 4-square step-test, static and dynamic balance.
Systems vary in how they may be assembled, but some versions of this technology feature snap-together design that allows for layouts that are straight or have turns, shaped in ovals, or cover an entire floor. They also can be used with steps and curbs to measure gait parameters in real-world settings.
The clinical value of these systems is summed by Margaret Wood, MSPT, physical therapist at University of Maryland Shore Regional Health, in a 2017 online video released by the university.
Wood explains that one of the key components of care physical therapists provide is to help some patients walk more safely and efficiently, and return a person recovering from a gait impairment to normal daily life. By measuring gait, she says, therapists can break down components of how a patient walks and help them improve the ability to walk.
“[This technology] is used to objectively measure gait or walking in time and space. As the patient walks across the walkway, the system with the sensors on the side captures the geometry and the timing of each and every one of [the patient’s] footfalls.”
She notes that the gait mat system she works with provides specific data related to a patient’s speed, step length, and, “what an individual’s walking actually looks like.”
The data these systems create can also be used to develop interventions, establish baseline function, measure performance pre- and post-intervention, and provide objective data that can be used to support decisions about providing a patient with services or devices.
Gait Analysis On the Go
The trend toward making equipment smaller is complemented by a parallel trend in making equipment more portable. Previous generations of gait mats provided sophisticated data but could take up considerable amounts of floor space, and once put into place were unlikely to be moved. Some of the newest models of gait mats and electronic walkways are designed to simply roll out onto a floor or other walking surface—including outdoor terrain—and begin collecting data in a matter of minutes. Other useful features among these types of technologies include concealed electronics and sloped edges that are useful when collecting data for individuals who use assistive devices such as canes and walkers.
Manufacturers have shrunk the footprint of these technologies as well while maintaining accuracy and performance. The result is technology that takes up less space and costs less than what previously has been available. It’s a welcome trend that should help objective gait analysis become a reality for clinics and facilities that once thought them too expensive or too cumbersome.
As these technologies become more affordable and accessible, clinics that want to bring this power in-house will want to research the functions each system offers. A wealth of reports and information about these technologies is available online and at manufacturer websites to help clinic managers and owners inform their purchases. Likewise, part of the pre-purchase homework should include in-person testing and conversations with current users.
Welcome to Wearables
Another area where miniaturization and portability are leaving their marks is wearable technologies. These small devices offer big performance, and the comfort consumers seem to have with them appears to be growing as devices such as fitness trackers surge in popularity.
Though not a wearable in the sense of small watch-like devices worn on the wrist, a pressure mapping system that fits inside a shoe offers a good example of a wearable technology that is small, powerful, and can be worn comfortably by the patient. The device is wireless, Bluetooth-enabled, and aims to provide unrestricted movement to the patient who wears a sensor attached to each shoe. The system is built to provide timing parameters that include cadence, step time, stride time, stance time, and swing time.
Exercise and therapeutic fitness activities typically will be important for keeping post-stroke patients healthy after discharge and throughout their rehabilitation period. However, individuals who have experienced a stroke tend to have very low levels of physical activity and are sedentary for up to 80% of their normal day.1 Residual neurological deficits can also influence the amount of physical activity in which post-stroke patients engage and ultimately reduce the amount of exercise they perform.2 Keeping post-stroke patients active can be helpful in flattening the risk of cardiac complication in recurrent events so physical therapists may be keen to keep track of the activity levels among this vulnerable patient population. One way to accomplish that is to use accelerometers.
As with gait analysis systems, accelerometry-sensing technologies historically were complex, expensive, and not particularly user-friendly. Physical therapists had few options for objectively assessing free-living physical activity patterns among stroke survivors. Recently, however, younger populations have embraced activity trackers that are user-friendly and affordable. This category of devices includes an ankle-worn consumer-level accelerometer that can accurately measure step counts—including treadmill walking. Likewise, it can calculate distance traveled, floors climbed, and calories burned. While the anatomical placement of these accelerometers can affect accuracy and reliability, they nonetheless can maintain a connection between the post-stroke patient and physical therapist, while providing data that keeps each one accountable to the other.
An example of how these small wearable devices serve stroke rehabilitation is summed by the authors of a 2018 report led by Jonathan Hui and published in Physiotherapy Canada. The peer-reviewed study investigated the effect of accelerometers on community-dwelling stroke survivors and left the authors to make the following conclusion:
“Using devices to monitor activity levels may be an integral component of promoting daily physical activity in this population. The participants in our study enjoyed using these activity-tracking devices, many experienced minimal to no complications, and several felt that the devices provided external motivation for activity change and would consider using them in the future.”
Good and Getting Better
Good gait analysis has never taken the path of least resistance, but medical and consumer device manufacturers have found ways to make these critical measures easier and more affordable. While the design trend has been toward smaller technologies at the same time wireless connectivity has also been integrated into these devices, making communication between patient and therapist easier than ever to maintain. As the rehab profession continues to move through the COVID-19 pandemic, this important feature will help blaze a trail toward outcomes that are more sustainable and accessible for all. RM
Frank Long, MS, is Editorial Director of Rehab Management. For more information, contact [email protected].
- Hui J, Heyden R, Bao T, et al. Validity of the FitBit One for measuring activity in community-dwelling stroke survivors. PhysiotherCan. 2018;70(1):81-89.
- Gresham GE, Fitzpatrick TE, Wolf PA, et al. Residual disability in survivors of stroke—the Framingham study. N Engl J Med. 1975;293(19):954–6.