Such devices can measure number of steps, distance walked, and sleep quality of a person with MS continuously. This could potentially supplement office visits.

The study was conducted to assess the feasibility of using a consumer wearable device to monitor activity among people with MS in a real-world setting. Fitbit One™ activity trackers were provided to 248 subjects. The three-week study showed that participants took a total of 15 million steps and walked 6,820 miles, the distance from Boston to Beijing.
“I got positive reinforcement to do more each day, and that really encouraged me. The Fitbit also allowed me to track what I was eating and how I was sleeping. I made more positive choices as a result,” said Annette Smiling, a study participant who had never used a wearable activity tracker before.
Source-Medindia