The physiological cost index of walking with a powered knee–ankle–foot orthosis in subjects with poliomyelitis: A pilot study

Background:A powered knee–ankle–foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait.Objective:The purpose of this study was to determine its effect on the physiological cost index, walking speed and the distance walked in people with poliomyelitis compared to when walking with a knee–ankle–foot orthosis with drop lock knee joints.Study design:Quasi experimental study.Methods:Seven subjects with poliomyelitis volunteered for the study and undertook gait analysis with both types of knee–ankle–foot orthosis.Results:Walking with the powered knee–ankle–foot orthosis significantly reduced walking speed (p = 0.015) and the distance walked (p = 0.004), and also, it did not improve physiological cost index values (p = 0.009) compared to walking with the locked knee–ankle–foot orthosis.Conclusion:Using a powered knee–ankle–foot orthosis did not significantly improve any of the primary outcome measures during w...