Photo: Courtesy of Quell

2 of 3

Who It's For: Those who suffer from fibromyalgia or chronic nerve, musculoskeletal, or joint pain.
How it Works: Though the device fastens onto your upper calf, it short-circuits pain anywhere in the body. The electrode stimulates sensory nerve clusters in your calf, and those nerves carry pulses to your brain, triggering a series of neurotransmitter responses that block pain. Quell can automatically deliver hour-long therapy sessions every other hour, and you can adjust the program or the intensity using an accompanying app.
What Our Testers Thought: "I run about 40 miles per week and tend to have pain in my knees when I walk. Some days it's so bad, I develop a little limp. I wore the device for an hour each night, right before bed, since the cuff and electrode were too bulky to wear under pants or tights. It stayed on while I walked around my apartment. I was surprised by how quickly it worked: The uncomfortable pressure I usually experience stopped after about three sessions." —Candy, 31