In the old days, back when Ana Espinal was wearing an Apple Watch on her wrist at the gym, she often found that her fitness app would shut down during her workout. Espinal has tiny wrists, she said, and she wondered if her loose watch was not able to register her heart rate.

So she sought solutions online, where she found a small community of people who had experienced similar issues and had rectified them in a novel way — by enlisting their ankles.

Espinal bought an adjustable Velcro strap at Marshalls that would fit the watch to her ankle, and presto: Problem solved.

“It’s perfect,” said Espinal, whose watch appears on TikTok, where she has more than 80,000 followers as a self-described fitness influencer. As she captioned a recent post, “Me putting my Apple Watch on my ankle while I work out cause if you know you know.” (Her followers know.)

A small but growing movement of ankle-watch acolytes has been afoot for a couple of years, as various users of Apple Watches strap them to their ankles as workarounds for various problems. Some medical professionals, for example, cannot wear anything on their wrists. Others have skin conditions or wrist tattoos that they believe interfere with the watch’s sensors.

And then there are step counters and fitness enthusiasts who say they get more accurate health statistics when they strap the watch to an ankle. Consider Espinal, 23, who never envisioned that she would become one of the crusade’s leading evangelists on social media.

“I have to tell my people about this,” said Espinal, who lives in Manhattan and works as a personal assistant for a fur and leather clothier. “They need to know.”

Shaniece Gale, 33, a medical assistant from Brampton, Ontario, uses her Apple Watch to track her steps. But after she gave birth to her son, Jalen, in 2023 and began pushing him around in a stroller, she discovered that the watch would record her steps only if she kept one arm free so that it could swing by her side.

“But then my other arm would always get tired from pushing the stroller,” she said. “So I was like: ‘You know what? Let me put it on my ankle.’”

Zoe Hughley Beasley, a loan officer from Columbia, Missouri, became a member of the ankle-watch cabal after her workplace invested in walking pads a couple of years ago. As she worked and walked at her standing desk, she found that her steps were not registering when the watch was on her wrist.

“Because I’m just typing emails, and you’re attached to your keyboard,” she said.

Like Gale, Hughley Beasley, 32, now wears the watch on her ankle whenever she pushes her newborn son, Brooks, in his stroller. The various metrics that the app tracks — heart rate, calories, distance — seem accurate, she said, even if her approach is unconventional.

“I know it’s ridiculous,” she said.

That was the gist of a TikTok that Shomar Griffiths, a teacher from Oshawa, Ontario, produced after he learned of the trend. In the video, Griffiths, 35, has the Apple Watch on his ankle and pretends to use it for everyday tasks like checking the time and using Apple Pay at the drive-thru window. It does not go well.

An Apple spokesperson declined to comment on the trend, but the company has stated in consumer support materials that several important features of the Apple Watch are specifically calibrated and validated for wear on the wrist — and not on other parts of the body. The watch, for example, uses LED lights paired with semiconductors to “detect the amount of blood flowing through your wrist at any given moment.”

But wearing an Apple Watch on other body parts can also lead to misunderstandings. Espinal recalled working out at her gym when an older woman noticed the watch on her ankle.

“‘Oh, my God,’” the woman said, according to Espinal. “‘What happened? You got in trouble?’”

Espinal had to explain that she was not, in fact, wearing an ankle monitor.

That sort of conversation is more common than any of these women would prefer. Hughley Beasley said she often feels as if she should be assuring her neighbors that she is not under house arrest. “It’s not what it looks like,” she said. “I promise.”

The twist is when it’s exactly what it looks like. Jason Rogers, an actor and author from Houston, said he had to wear an ankle monitor after a 2019 arrest on a charge of impaired driving.

“My niece asked, ‘Why are you wearing an Apple Watch on your ankle?’” he recalled.

Rogers, 38, turned that exchange into fodder for a popular TikTok that he titled “Kids Asked Why I’m Wearing My Apple Watch on my Ankle,” set to a snippet of a song by the R&B group Blackstreet: “You got your problems, baby, I got mine.”

Rogers said he spent two years with his ankle monitor. In hindsight, he said, it was a blessing because he worked his way through it and learned his lesson.

But could he envision intentionally wearing something on his ankle again?

“Absolutely not,” he said.