Wearable exoskeletons have moved out of research labs and rehabilitation clinics and into everyday life. Hikers are wearing them on long descents, active older adults are using them to keep up on stairs, and people with tired or sore knees are looking for a little mechanical help on daily walks. That popularity has also filled search results with look-alike listings, vague claims, and devices that are little more than a strap with a spring. Buying online makes it harder, because you cannot strap a unit on and walk around the block before you pay. The good news is that quality leaves a paper trail. If you know which details to…