Treat your feet with the Vionic with Orthaheel Technology Addison Slip-On.Leather upper in a casual slip-on style. Round toe. Twin elastic goring panels ensure a secure fit. Padded collarLeather lining. Podiatrist-designed Orthaheel® Technology provides superior orthotic support, relief and stability which helps realign feet back to the natural position. Research supports Orthaheel® Technology’s success in reducing over-pronation, which can help relieve associated common aches and pains such as heel pain, knee pain and lower back pain.