Some health apps are able not just to diagnose diseases, but also to treat them

“IT LOOKS LIKE your back is a bit tight today. Let’s modify your workout.” The voice is gentle yet commanding, the instructions rolled out in the signature cadence of a physiotherapist. It is also unmistakably robotic. The AI physio issues her commands straight from a smartphone’s speakers. A phone with a camera is all she needs to do her job: select the exercises to suit the patient’s injury, guide him through each session and order corrections when he is not doing something right (bending a knee at the wrong angle, for example). An AI algorithm marks up his body as he moves, which is how it knows when a joint is hurting or the back is stiffer than the day before.