Lower Limb Exoskeletons for Pediatric Gait Rehabilitation: A Brief Review of Design, Actuation, and Control Schemes

Neurological disorders such as Cerebral Palsy (CP) and spinal cord injury (SCI) adversely affect the lower-body movement of the pediatric population. Such movements can be improved by carrying out rehabilitation measures using exoskeleton technology. Although several lower-limb exoskeleton systems have been developed; however, most are for elderly people rather than children. Moreover, there is minimal literature available on existing pediatric gait exoskeleton systems. This work systematically reviews the design, actuation, and control of different exoskeleton systems for pediatric gait rehabilitation to address the literature gap. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement is provided to show the inclusion and exclusion criteria of related publications from the literature. Thereafter, design aspects (namely assist joint, active DOFs, weight), actuation methods (namely type, minimum torque/force), and control schemes (namely supervisory level, high-level and low-level) are presented for each exoskeleton. A generalized dynamic formulation for the design of such exoskeletons is given in design passive-assist and active-assist modes. Finally, a few major concerns hindering the development of pediatric exoskeletons are discussed.