Advancement in Knee Ankle Foot Orthosis (K.A.F.O.) for Individual with Post-Polio Residual Paralysis (P.P.R.P): A Systematic Review

Abstract

Background: Post-polio residual paralysis (PPRP) presents a significant challenge in rehabilitation medicine, particularly affecting knee joint stability and functional mobility. It necessitating orthotic solutions that balance biomechanical support with functional restoration. There is different type of Knee Ankle Foot Orthosis (KAFO) used in patient with PPRP who have many types of orthotic knee joint i.e.  Modified Ring Lock Knee Joint, Automatic Spring Lever Knee Joint, Posterior Offset Free Motion Knee Joint, Automatic Angled Lever Lock, Load Response Knee Joint, Microprocessor orthotic knee joint etc. Objective: This systematic review examines advancements in orthotic knee joint design, biomechanical foundations, material innovations, and clinical outcomes for PPRP populations.  Authar was thoroughly analysed focusing on stance-control mechanisms, powered orthoses, advanced materials, and impacts on gait parameters and comfort in many studies. Method: A PRISMA-compliant systematic search was conducted across PubMed, Google Scholar, Scopus, Web of Science, and IEEE Xplore from January 1987 to October 2025 and also the study duration from January 2025-October 2025. Inclusion criteria encompassed peer-reviewed studies on adults (≥18 years) with PPRP knee instability using advanced KAFO knee joints (e.g., stance-control, microprocessor-controlled), reporting gait parameters, energy expenditure, or patient satisfaction, compared to traditional locked KAFO.  Results: Of 590 records identified, 20 studies (n=8-35 per study; mean age 45-62 years) met criteria after screening and eligibility assessment. Stance-control KAFOs improved gait velocity by 0.10-0.18 m/s (p<0.05; 12 studies), stride length by 0.08-0.14 m (14 studies), and reduced energy expenditure by 8-18% (9 studies) versus locked KAFOs. Microprocessor systems enhanced swing-phase knee flexion (55-65°) and patient satisfaction. Conclusion: Orthotic knee joint technology has seen substantial advancements in biomechanics and control systems. Personalized approaches considering individual PPRP characteristics and functional goals are important for optimal outcomes. Further research is needed on long-term clinical outcomes and cost-effectiveness analysis.