Evaluating effects of a new hip-knee-ankle-foot orthosis on gait parameters in healthy individuals

Abstract

Hip-knee-ankle-foot orthoses (HKAFOs) are commonly used to assist gait; however, conventional designs are associated with high energy expenditure and poor mediolateral balance. This pilot study examined whether permitting additional motion in selected hip and ankle planes altered joint kinematics and dynamic-balance parameters in healthy participants. A randomized cross-over trial was conducted with 20 healthy participants aged 18-25. Gait performance was evaluated under five conditions: conventional HKAFO (locked/unlocked knee), Multiflex HKAFO (locked/unlocked knee), and no orthosis. Kinematic and balance data were collected. Key variables analyzed included center of pressure (CoP) velocity, mediolateral sway, and joint range of motion (ROM). Compared with the conventional HKAFO configurations, the Multiflex HKAFO permitted greater abduction/adduction and ankle inversion/eversion ROM. With the Multiflex HKAFO and an unlocked knee joint, CoP velocity and mediolateral excursion were not significantly different from walking without an orthosis. However, knee flexion/extension and ankle dorsiflexion/plantarflexion remained restricted relative to walking without an orthosis. In healthy participants, the Multiflex HKAFO permitted greater motion in selected hip and ankle planes than the conventional design while producing lower center-of-pressure velocity and mediolateral excursion in some configurations.