A portable powered ankle-foot orthosis for rehabilitation

Abstract

Abstract-Innovative technological advancements in the field of orthotics, such as portable powered orthotic systems, could create new treatment modalities to improve the functional outcome of rehabilitation. In this article, we present a novel portable powered ankle-foot orthosis (PPAFO) to provide untethered assistance during gait. The PPAFO provides both plantar flexor and dorsiflexor torque assistance by way of a bidirectional pneumatic rotary actuator. The system uses a portable pneumatic power source (compressed carbon dioxide bottle) and embedded electronics to control the actuation of the foot. We collected pilot experimental data from one impaired and three nondisabled subjects to demonstrate design functionality. The impaired subject had bilateral impairment of the lower legs due to cauda equina syndrome. We found that data from nondisabled walkers demonstrated the PPAFO's capability to provide correctly timed plantar flexor and dorsiflexor assistance during gait. Reduced activation of the tibialis anterior during stance and swing was also seen during assisted nondisabled walking trials. An increase in the vertical ground reaction force during the second half of stance was present during assisted trials for the impaired subject. Data from nondisabled walkers demonstrated functionality, and data from an impaired walker demonstrated the ability to provide functional plantar flexor assistance.

The road ahead for rehabilitation robotics

“…In line with this editorial's emphasis on lifelong rehabilitation, two articles present robots with potential as takehome devices. Shorter et al discuss their portable active ankle-foot orthosis, an untethered wearable device for rehabilitation of gait disorders [15], while Perry et al address issues of usability and cost reduction with a variable pantograph mechanism that can be quickly reconfigured for different tasks or joints in the upper limb [16]. Finally, the potential use of robotic therapy in maintaining function in degenerative disorders has been largely unexplored.…”

A Preliminary Study on Robot-Assisted Ankle Rehabilitation for the Treatment of Drop Foot

“…While treatments, such as braces and orthotics [7][8][9], functional electrical stimulation [10][11][12] and surgery [13], have been demonstrated to be effective for drop foot, physiotherapy as the primary treatment is commonly prescribed together with other options to maximize the function of the patient [14,15]. Strengthening exercises of the muscles within the foot and the lower limbs help maintain muscle tone, and improve gait pattern associated with drop foot.…”

A New Development of Powered Orthotic for Deficient Push-Off Power

“…But, this approach may not influence the kinetics of the ankle and foot. Some devices have been developed which impact kinetics but these do not appear to be designed so as to provide supplemental power at push-off [10]. Thus, these existing orthotics do not reform efficiency and power for the time of toe-off (GRF2) [5].…”