Design Considerations for the Development of Lower Limb Pediatric Exoskeletons: A Literature Review

Cerebral Palsy is the most prevalent cause of gait disorder in childhood, affecting the range of motion, power, and joint torques of children. Several treatments are available, ranging from physical therapy to surgery. However, these treatments are usually complex, costly, and long. Robotic exoskeletons could provide longer, more frequent, and personalized training sessions with quantified data on the gait characteristics. Unfortunately, very few pediatric exoskeletons are available compared to those for adults. Therefore, design guidelines are needed for the development of pediatric exoskeletons to facilitate market entry. This article proposes design considerations through an in-depth review of the available pediatric lower-limb exoskeletons. This research has identified nine exoskeletons with at least one actuated joint at the ankle level and discussed their clinical, mechanical, and control characteristics. Although all the identified exoskeletons use electric motors to reduce their weight, improvements must be made to further minimize it. In addition, these exoskeletons need to be more easily adaptable to the user's morphology. Impedance control methods are commonly used, which ensures the interaction safety. However, they should be more personalized to the specific neurological deficiencies. Furthermore, stronger validation of these exoskeletons is required through clinical trials.