SUMMARY

• Incorrect walker is associated with increased fall risk in older adults, but little is being done to correct the issue.
• Our product, the StrideTech Go, measures the two most common methods of incorrect walker use: 

1. Excessive weight through the handles (measured as left- and right-hand force on the left- and right-hand handles)
2. Excessive distance between the user and the device (measured as the distance between the user’s hip and the frame of the walker) 

• With StrideTech Go, we can decrease average weight through the handles and average distance between the user and their device over 11 weeks
• With StrideTech Go, we can visually and mathematically detect weekly patterns of mobility behavior
• With StrideTech Go, we can visually and mathematically detect daily patterns of mobility behavior

‍

INTRODUCTION

Stride Tech Medical Inc.’s mission is to prevent falls. Seniors widely use walkers to maintain mobility while reducing the risk of falls. Despite the benefits, habitually poor walker use, marked by excessive weight on the walker handles and/or excessive distance between the user and the walker, can lead to muscle atrophy, poor posture, and falls. A widely publicized investigation in 2009 showed that over 87% of severe falls with an assistive device occurred with a walker. They recommended increased time devoted to fitting and education on proper use. Eleven years later, most seniors still do not receive individualized fitting or training on how to use their walkers.

Our product, the StrideTech Go (STG), is an attachable walker accessory that integrates sensors and biofeedback onto existing walkers to correct common misuses in real time. Grip covers embedded with sensors Velcro over the handles of a walker. An additional sensor is mounted to the frame which measures the distance from the user’s hip to the walker frame. The grip covers vibrate if the sensors detect either of the two primary indicators of walker misuse:

• Excessive weight through the handles
• Excessive distance between the frame of the walker and the use

StrideTech Go is the first commercial product to help fill the urgent need for long term training in walker use. This white paper will outline the technical background and testing that has been done to establish efficacy, as well as briefly outline next steps and improvements. 

‍

PROTOCOL

StrideTech defines long-term efficacy as the ability to see changes in STG measures of walker use over the course of at least six weeks. This time came as the minimum recommendation of long-term testing from various physical therapist advisors to the team. The data presented was collected from a volunteer, Barbara, who agreed to attach the StrideTech Go to her personal walker for six weeks. (After six weeks of use, she wished to continue using the product, so the team extended the testing trial an additional five weeks.) The threshold levels to initiate vibratory and visual feedback were set at the standard 18 in. for hip-distance feedback, and 7 lbs. for weight-bearing feedback. 

‍

On a weekly basis, the StrideTech team would meet with Barbara to download the previous week’s data from the StrideTech Go, replace the device’s SD card, display walker use data, and get feedback on how well the device was functioning. 

‍

RESULTS

Case Study 1 – Patterns in weekly activity can be detected

Below is a sample of Total Active Time (hrs) detected by the StrideTech Go per day over the course of two weeks. StrideTech Go estimates walker activity time by summing the total time in a day that both hip distance and weight-bearing are detected at the same time, indicating that the walker is in use. The team repeatedly saw patterns of low activity times (less than 1 hr per day) that usually occurred on Mondays and Tuesdays. When asked about these dips in walker activity and use, Barbara reported those as “rest days”. Her family usually visited on weekends, resulting in several days in a row of above-average activity and walking. She would then use Mondays and Tuesdays as “rest days” (highlighted in purple) to recuperate from the highly active days with her family (highlighted in blue).

‍

A simple examination of the trends found in Barbara’s walker activity time led to a reasonable explanation in the wide variance of activity time seen throughout the week. This in turn was vital to the StrideTech team, as it allowed us to 1. Understand why these trends were occurring and 2. When giving weekly reports and updates, we did not focus on encouraging increased activity early in the week. 

‍

Case Study 2 – Patterns in daily activity can be detected

Below is an average pattern of activity seen throughout a single day. On the x-axis is the hour of day relative to a 24-hour clock. (I.e. hour 0 translates to 12 AM, hour 12 translates to 12 PM.) On the y-axis are the relative activity level for hip distance (in black) and force (in blue). Here relative activity level refers to how often the activity is recorded at that time in the day across the 11 weeks of the trial, essentially a histogram of active hours. Based on the data, it was determined that Barbara usually leaves bed and begins using her walker shortly before 10 AM, with peak walker use typically in the late afternoon, and then retires to bed between 8 PM and 9 PM, with sporadic activity throughout the night. When interviewing Barbara about this, she confirmed this as a typical daily schedule.

‍

There is great potential value in measuring, recording, and reporting daily activity patterns. Because we were able to confirm Barbara’s typical wake, sleep, and nighttime use of her walker, and because we know dramatic changes in behavior may be indicative of underlying health issues, a-typical patterns could be a cause for concern or check-in. For example, the increased nighttime activity could indicate anything from insomnia to a urinary tract infection. If we see no activity at all throughout the day, the user may not be using their walker at all, could have suffered from a fall and unable to get up, or may be experiencing feelings of depression. While the data cannot diagnose any problems, it can alert caregivers and loved ones to significant deviations from normal behavior that could lead to earlier health or behavior interventions. 

‍

FUTURE WORK 

More data and more testing are needed to explore the exciting potential of the StrideTech Go. Future work will call for longer testing sessions (to allow for increased pattern observations within and between days). Future versions of the StrideTech Go could include automatic alerts to caregivers and loved ones regarding distressing deviations from normal activity behavior.

‍