Advances on mechanical designs for assistive ankle-foot orthoses

Assistive ankle-foot orthoses (AFOs) are powerful solutions to assist or rehabilitate gait on humans. Existing assistive AFO technologies include passive, quasi-passive, and active principles to provide assistance to the users, and their mechanical configuration and control depend on the eventual support they aim for within the gait pattern. In this research we analyze the state-of-the-art of assistive AFOs and classify the different approaches into clusters, describing their basis and working principles. Additionally, we reviewed the purpose and experimental validation of the devices, providing the reader with a better view of the technology readiness level. Finally, the reviewed designs, limitations, and future steps in the field are summarized and discussed.Comment: Figures appear at the end. Article submitted to Frontiers in Bioengineering and Biotechnology (currently under review

Application of wearable sensors in actuation and control of powered ankle exoskeletons: a Comprehensive Review

Powered ankle exoskeletons (PAEs) are robotic devices developed for gait assistance, rehabilitation, and augmentation. To fulfil their purposes, PAEs vastly rely heavily on their sensor systems. Human–machine interface sensors collect the biomechanical signals from the human user to inform the higher level of the control hierarchy about the user’s locomotion intention and requirement, whereas machine–machine interface sensors monitor the output of the actuation unit to ensure precise tracking of the high-level control commands via the low-level control scheme. The current article aims to provide a comprehensive review of how wearable sensor technology has contributed to the actuation and control of the PAEs developed over the past two decades. The control schemes and actuation principles employed in the reviewed PAEs, as well as their interaction with the integrated sensor systems, are investigated in this review. Further, the role of wearable sensors in overcoming the main challenges in developing fully autonomous portable PAEs is discussed. Finally, a brief discussion on how the recent technology advancements in wearable sensors, including environment—machine interface sensors, could promote the future generation of fully autonomous portable PAEs is provided

Treadmill training augmented with real-time visualisation feedback and function electrical stimulation for gait rehabilitation after stroke : a feasibility study

Motor rehabilitation typically requires patients to perform task-specific training, in which biofeedback can be instrumental for encouraging neuroplasticity after stroke. Treadmill training augmented with real-time visual feedback and functional electrical stimulation (FES) may have a beneficial synergistic effect on this process. This study aims to develop a multi-channel FES (MFES) system with stimulation triggers based on the phase of gait cycle, determined using a 3D motion capture system. A feasibility study was conducted to determine whether this enhanced treadmill gait training systemis suitable for stroke survivors in clinical practice. The real-time biomechanical visual feedback system with computerised MFES was developed using six motion-capture cameras installed around a treadmill.;This system was designed to stimulate the pretibial muscle for correcting foot drop problems, gastro-soleus for facilitating push-off, and quadriceps and hamstring for improving knee stability. Dynamic avatar movement and step length/ratio were displayed on a monitor, providing patients with real-time visual biofeedback. Participants received up to 20 minutes of enhanced treadmill training once or twice per week for 6 weeks. Training programme, pre- and post-training ability, and adverse events of each participant were recorded. Feedback was also collected from participants and physiotherapists regarding their experience. Eight out of ten participants fully completed their programme.;In total, 67 training sessions were carried out. All participants had a good attendance rate. The number and duration of training sessions ranged from 5 to 20, and 11 to 20 minutes, respectively. The MFES system successfully improved gait patterns during training, and feedback from participants and physiotherapists regarding their experience of the research intervention was overwhelmingly positive. In conclusion, this enhanced treadmill gait training system is feasible for use in gait rehabilitation after stroke. However, a well-designed clinical trial with a larger sample size is needed to determine clinical efficacy on gait recovery.Motor rehabilitation typically requires patients to perform task-specific training, in which biofeedback can be instrumental for encouraging neuroplasticity after stroke. Treadmill training augmented with real-time visual feedback and functional electrical stimulation (FES) may have a beneficial synergistic effect on this process. This study aims to develop a multi-channel FES (MFES) system with stimulation triggers based on the phase of gait cycle, determined using a 3D motion capture system. A feasibility study was conducted to determine whether this enhanced treadmill gait training systemis suitable for stroke survivors in clinical practice. The real-time biomechanical visual feedback system with computerised MFES was developed using six motion-capture cameras installed around a treadmill.;This system was designed to stimulate the pretibial muscle for correcting foot drop problems, gastro-soleus for facilitating push-off, and quadriceps and hamstring for improving knee stability. Dynamic avatar movement and step length/ratio were displayed on a monitor, providing patients with real-time visual biofeedback. Participants received up to 20 minutes of enhanced treadmill training once or twice per week for 6 weeks. Training programme, pre- and post-training ability, and adverse events of each participant were recorded. Feedback was also collected from participants and physiotherapists regarding their experience. Eight out of ten participants fully completed their programme.;In total, 67 training sessions were carried out. All participants had a good attendance rate. The number and duration of training sessions ranged from 5 to 20, and 11 to 20 minutes, respectively. The MFES system successfully improved gait patterns during training, and feedback from participants and physiotherapists regarding their experience of the research intervention was overwhelmingly positive. In conclusion, this enhanced treadmill gait training system is feasible for use in gait rehabilitation after stroke. However, a well-designed clinical trial with a larger sample size is needed to determine clinical efficacy on gait recovery

Wearable Movement Sensors for Rehabilitation: From Technology to Clinical Practice

This Special Issue shows a range of potential opportunities for the application of wearable movement sensors in motor rehabilitation. However, the papers surely do not cover the whole field of physical behavior monitoring in motor rehabilitation. Most studies in this Special Issue focused on the technical validation of wearable sensors and the development of algorithms. Clinical validation studies, studies applying wearable sensors for the monitoring of physical behavior in daily life conditions, and papers about the implementation of wearable sensors in motor rehabilitation are under-represented in this Special Issue. Studies investigating the usability and feasibility of wearable movement sensors in clinical populations were lacking. We encourage researchers to investigate the usability, acceptance, feasibility, reliability, and clinical validity of wearable sensors in clinical populations to facilitate the application of wearable movement sensors in motor rehabilitation