Apple’s Revolutionary Wheelchair Activity Tracker

Of the many apps introduced during Apple’s Worldwide Developers Conference, none was more intriguing than the Wheelchair Activity Tracker. It may also be the 2016 app the company is most proud of. As Ron Huang, Director of Software Engineering for Location and Motion Technologies put it, “Apple has always led on the accessibility features. Even when we were finishing watchOS 1.0, we knew we wanted to do something for wheelchair users.”

That something includes two new wheelchair workout apps, “Time to Stand” notifications, “time to roll” notifications, plus Activity ring optimization. The new features will ship with watchOS 3 later this fall. One of the impetuses behind these developments is the urgent need for wheelchair users to move. Since wheelchair users are more likely to be sedentary than non-wheelchair bound people, they can develop health problems such as obesity that could be prevented with more activity.


It took Apple over a year to develop the features. Although there are more than 2 million people who use wheelchairs in the USA alone, little work has been done on measuring and monitoring activity. Apple eventually realized that monitoring movement would not be similar to counting steps. Instead, watch sensors needed to take the following into account:

  • How far the arms travel in an arc to create wheel spin
  • Different types of push
  • Different terrain, since whether the ground is downhill, uphill, rocky or smooth impacts activity
  • Inactive gestures
  • Distance
  • How much caloric value is assigned to activity
  • Wheel width, chair height and other specs

Apple decided to create its own custom algorithms. The company teamed up with the Challenge Athletes Foundation and the Lakeshore Foundation to start a study on wheelchair use. People who participated in the study wore oxygen masks to monitor their oxygen intake and count the calories they burned. The company also focused on getting data in everyday situations.

Apple eventually accumulated over 3,500 hours of data. Using the data, Apple finally learned how to categorize and measure pushes, which would be the equivalent of steps. The app learned to count three different push styles, which also helped develop greater accuracy, since a push is ultimately not the same as a step.


“The first is in a semicircle, pushing from 10 O’clock to 3 O’clock,” Huang said.

“The second is called an arc push, and it’s what you do when you have to push yourself up an incline: shorter, more powerful pushes with a quick jerk to the return position to prevent yourself from rolling back.”

And the third? “Finally, there’s the semi-loop-over: a pushing style that tends only to be done in competitive situations, like wheelchair racing, where you’re really leaning into the push.”

The end-result is yet another example of Apple leading in accessibility functions and solutions. The company has long offered out-of-the-box capabilities for people with disabilities, rather than making users foot the bill.


You May Also Like


  1. 1
  2. 2
  3. 3

    What a fascinating development process. It’s great they invested the time and energy to do this for people in chairs.

  4. 4
  5. 5

Leave a Reply

Your email address will not be published.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>