NaviGAIT
Spring 2022
Creating an effective tool for clinicians to conduct gait analysis.
Clinical Problem Identification
Each year, 65% of runners in the United States, or 40 million runners, experience a running-related injury. An examination known as gait analysis, which is currently used to study the runners' biomechanics, diagnose injuries, and increase the efficiency of running, could also preemptively prevent many of these running-related injuries. Just as routine dental checkups help prevent cavities and gum disease, regular gait analysis could help prevent injury.
We partnered with Dr. Erin Angelini (left) at the UPMC Sports Medicine Clinic (right) to learn more about how gait analysis is conducted. We learned that the process takes a long time and requires the physical therapist to transfer videos between many devices and measure the angles of the patient by hand. This meant that gait analysis was too inefficient to be conducted often enough as a means of preventative care.
With these problems in mind, we asked ourselves how might we decrease the time of gait analysis so that it can be conducted frequently and proactively with the potential to ultimately improve preventative care for runners?
Pretotype 1:
The first idea we had was to minimize the time it took for the clinician to draw out the angles during the gait analysis. To achieve this, we used an iPad to take the videos and simulated Dr. Angelini to draw the angles by hand by placing a clear plastic cover over the iPad.
This idea was well received by the clinicians as it made it simple to draw the angles by hand and there was no time between taking the video of the patient and drawing the angles.
Pretotype 2:
The second idea we had was to minimize the time it took to explain the results of the gait analysis to the patient. To simulate this, we used a fake leg and a clear screen. This gave the clinician the ability to draw out the angles of the specific patient and have a live prop that could be used to demonstrate the corrective motions the patient would need to conduct.
This idea was also well received as Dr. Angelini believed a visual aid would help patients understand the process of gait analysis better. However, the time to set up the visual aid took longer than her normal explanation.
Pretotype 3:
The final idea was also a way to minimize the time it took to explain the results of the gait analysis to the patient. For this, we made physical angles out of foamcore and pushpins. The clinician could set the angle like a protractor and hold it up to the patient's legs to show them the angles they are currently at versus the optimal angles.
This idea worked well when describing the angles in the ankle, but it was ineffective for the back and knee angles as they can not be as easily set on the makeshift protractor.
Based on the feedback we received from our first round of pretotypes, we decided to focus on minimizing the time of the analysis itself instead of the patient interaction portion. We came up with six design constraints for our prototype:
1. The setup of the device takes under two minutes
2. The analysis takes less than ten minutes
3. The device is self-contained and can store all required materials
4. The video recording and analysis can be conducted on one device.
5. The markers do not inhibit the patient's ability to run.
6. The angles of the patient can be automatically detected.
Once these constraints were defined, we started the iterative design process to create a housing for the device, a mechanism for automatic angle analysis, and non-invasive markers.
My first main role in this project was finding the best material and size for our markers. Since they had to be picked up by the camera from about six feet away, the makers needed to be large enough to be seen but small enough that they would not hinder any running movements. Initially, I wanted to use soft goods such as fabric and vinyl stickers to display the markers. This could be easily cleaned as well. However, we found the markers weren't stable enough when made of fabric to keep their shape and be seen by the camera. In the end, I ended up choosing paper makers that were laminated. I tested three different sizes and found that three-inch squares work best for our distance and running needs. I glued them to elastic velcro bands that could easily be placed around the patient's leg, knee, or waist.
My second role was being a clinical liaison. Since I knew the most about physical therapy and gait analysis in my team, I was tasked with communicating with the clinicians and making sure our design choices did not diverge from the main point of gait analysis. Also, I documented all the clinician interactions and testing that we conducted. This helped us review it later as a team and learn from the videos as we were not always able to write every detail down. In this video, Dr. Angelini is trying out one of our later prototypes with a makeshift cart.
The Final Design
This is the initial setup used in the clinic. Dr. Angelini sets up a camera on a tripod on this box step. She must gather all the individual items and set them up. She then records from one side of the treadmill and pushes the entire setup to the back of the treadmill. She then has to transfer the video from the camera to her computer, where she performs the analysis.
In our final design, we have a cart with space for storage so she can keep all the materials, like the markers, in one place. In addition, the cart is on wheels so she can easily move it from one side of the treadmill to the other. In addition, the video is taken on the iPad, and uploaded to the website we made that will output the video with automated angles in less than two minutes.
This is what the final outputed video displays.
Overall, we were able to achieve five out of six of our design goals. We were unable to fully test if the markers hinder a patient's ability to run properly as we only tested with people who had proper gaits, so we need to conduct more testing to know for sure.
Design Expo
At the end of the semester, we had the opportunity to present our project at the University of Pittsburgh Swanson School of Engineering Spring 2022 Design Expo. This was an invaluable experience where we could connect with judges and speak with the public about the work we did.