Medical exoskeletons are devices that aim to augment the mobility of subjects affected by disorders caused by musculoskeletal and neurological diseases. Due to the complex anatomy of human joints and the wide variety of human body sizes, the design of a device able to fit properly on different subjects is a difficult task. This causes the appearance of misalignment between the exoskeleton joint axes and the human joint ones, and consequently a decrement of the overall performance of the exoskeleton and of the comfort perceived by the user. The thesis aims to investigate the strategies to suppress or minimize the negative aspects of incorrect fit, focusing on the design of a misalignment-compensating mechanism.