A report from The New York Times highlighted the trend of people wearing an Apple Watch on their ankles, instead of the wrist.
Reasons for wearing Apple Watch on the ankle: some people find it fits too loosely on their wrists for heart rate sensing, wrist tattoos may interfere with heart rate sensing, some people believe it provides more accurate step counting, people with skin conditions prefer it, and some medical professionals cannot wear anything on their wrists.
Apple has not commented on the trend and its documentation does not acknowledge wearing the Apple Watch on the ankle.