HOPSA Dress The HOPSA Dress By Dr. Lilli NielsenPurposeThe HOPSA-dress (H-d) is designed to give wheelchair users the opportunity to move their legs, learning to bear their own weight, balance while standing, and achieve the ability to walk.Technical InformationThe H-d is manufactured in three sizes to fit persons 1-7 years of age, 7-14, and adults.