I'm post ORIF for a tri-malleolar fracture. I ordered this because the CAM boot I was given by the ortho had an air pump on the shin and I use the iwalk or a knee walker and it was very uncomfortable. I bought a medium, I wear a size 41 european, a 9.5-10 womens. I'm going to take it with me to my physical therapy appt tomorrow for them to look at it.Overall, it felt like it runs big. I was struggling to get it snug, without inflating the air bladders. After inflation I could get it more snug, bSee full review