A Comparative Study of the Effectiveness of Indigenously Developed Knee-Ankle-Foot Orthosis with Stance Control Knee Joint and Knee-Ankle-Foot Orthosis with Drop Lock Knee Joint in Post-Polio Residual Paralytic Patients
Authors: Tiwari Manoj Kumar , Madkaikar Yogeeta , Gaur Dr. Anil Kumar 
Published: November 2022

Background and purpose: Individuals with quadriceps weakness have difficulty generating the knee-extension moments required to complete everyday mobility tasks. Patients with quadriceps muscle weakness are often prescribed a knee-ankle-foot-orthosis (KAFO), which locks the knee in full extension during both the stance and swing phases of gait. Abnormal gait patterns are characterized by hip hiking and leg circumduction during the swing phase due to the locked knee. A stance control knee-ankle-foot-orthosis (SCKAFO) was developed to provide active flexion and extension of the knee joint during the swing phase of gait and restriction of the knee joint during the stance phase, thereby supporting the limb during weight-bearing. The developed design consists of a knee joint controlled electro-magnetically, allowing free knee flexion during the swing and secured stance phases in poliomyelitis patients. This study aimed to evaluate the potential of the indigenously developed SCKAFO with electro-magnetically controlled knee joint by determining its effect on spatiotemporal gait parameters, the physiological cost index (PCI), and improving quality of life in poliomyelitis patients compared to when walking with a KAFO with drop lock knee joint.
Methodology: By convenience sampling, five subjects of poliomyelitis with quadriceps weakness fulfilling the inclusion criteria were enrolled in the study. A custom-made stance control knee-ankle-foot orthosis (SCKAFO) with the same components was constructed for each participant. Gait analysis was performed on each patient with KAFO with drop lock knee joint and SCKAFO. Energy expenditure was measured by calculating the Physiological Cost Index (PCI), and the Orthotics Prosthetics Users Survey-Health Quality of Life Index (OPUS: HQOL) questionnaire was administered to assess the quality of life of poliomyelitis patients.
Results: Indigenously developed SCKAFO is significantly effective in increasing step length, stride length, cadence, and speed, reducing the physiological cost index, and improving the health quality of life of the patients. Walking with the SCKAFO significantly increased walking speed (p=0.03) and other spatiotemporal gait parameters and reduced PCI (p=0.03) compared to walking with the locked KAFO.
Conclusion: SCKAFO significantly improved spatiotemporal gait parameters and quality of life and reduced energy expenditure of poliomyelitis patients in walking. Compensatory movements, which were indispensable for walking with a locked knee, were reduced. Thus primary outcome measures were achieved during walking for poliomyelitis subjects with SCKAFO.
Clinical Relevance: This newly developed SCKAFO design improved the PCI of walking for people with post-polio residual paralysis compared to walking with a locked KAFO. The SCKAFO may contribute to improved quality of life and health status of persons with lower-extremity impairments by providing the ability to have better walking speed, endurance, and functional balance.

Key words: Knee-ankle-foot orthosis, stance control knee-ankle-foot orthosis, spatiotemporal, gait, quadriceps, walking