to echo Kaitlin’s comment – in my early days of PT, a PT guy found that one of my legs was slightly shorter than the other.  So he gave me orthotics with a slight lift.  These worked for a while. but then i started working with another PT and he worked soft tissue and adjusted spine/pelvis and found that he could get my legs the same length. Whoa. later i learned that many with leg length issues could be fixed without orthotics, but required other types of therapy.  i tossed my orthotics and fixed my movement patterns.  Everything worked naturally better.  So yeah it was in vogue to use orthotics many years ago, and for some who have permanent structural problems like true bone length issues, they will require orthotics.  but for people like me, it’s better to fix the muscular and skeletal problems, as well as fix movement patterns.  then i don’t need orthotics as a crutch, which was probably causing other problems like cramping out during a marathon, etc.