Advances in the clinical application of orthotic devices for stroke and spinal cord injury since 2013

Development of an individualized stable and force-reducing lower-limb exoskeleton

In this study, an individualized and stable passive-control lower-limb exoskeleton robot was developed. Users' joint angles and the center of pressure (CoP) of one of their soles were input into a convolutional neural network (CNN)-long short-term memory (LSTM) model to evaluate and adjust the exoskeleton control scheme. The CNN-LSTM model predicted the fitness of the control scheme and output the results to the exoskeleton robot, which modified its control parameters accordingly to enhance walking stability. The sole's CoP had similar trends during normal walking and passive walking with the developed exoskeleton; they-coordinates of the CoPs with and without the exoskeleton had a correlation of 91%. Moreover, electromyography signals from the rectus femoris muscle revealed that it exerted 40% less force when walking with a stable stride length in the developed system than when walking with an unstable stride length. Therefore, the developed lower-limb exoskeleton can be used to assist users in achieving balanced and stable walking with reduced force application. In the future, this exoskeleton can be used by patients with stroke and lower-limb weakness to achieve stable walking.

Comparison between prefabricated ankle-foot orthoses, Dyna Ankle and UD Flex, in patients with hemiplegia

OBJECTIVE

To compare the kinematic effects of two widely-used prefabricated ankle-foot orthoses (AFOs), the Dyna Ankle (DA) and UD Flex (UD), on the gait cycle of patients with hemiplegia due to cerebral palsy or acquired brain injury.

METHODS

This was a retrospective cohort study involving 29 patients. Gait analysis results were assessed under three conditions: barefoot, with the DA, and with the UD. Friedman tests and post hoc analysis with Bonferroni correction were performed to assess differences between the three conditions.

RESULTS

The DA significantly improved ankle dorsiflexion during the mid-swing phase, making it more effective in correcting foot drop compared with the UD (DA: 2.28°, UD: 0.44°). Conversely, the UD was more effective in preventing knee flexion during the loading response (DA: 28.11°, UD: 26.72°).

CONCLUSIONS

The DA improved ankle dorsiflexion during the swing phase significantly more than that with the UD in patients with hemiplegia. Compared with the DA, the UD more effectively prevented increased knee flexion during the loading response. The choice to prescribe these orthoses should consider individual patient characteristics.

The Upper Limb Orthosis in the Rehabilitation of Stroke Patients: The Role of 3D Printing

Stroke represents the third cause of long-term disability in the world. About 80% of stroke patients have an impairment of bio-motor functions and over half fail to regain arm functionality, resulting in motor movement control disorder with serious loss in terms of social independence. Therefore, rehabilitation plays a key role in the reduction of patient disabilities, and 3D printing (3DP) has showed interesting improvements in related fields, thanks to the possibility to produce customized, eco-sustainable and cost-effective orthoses. This study investigated the clinical use of 3DP orthosis in rehabilitation compared to the traditional ones, focusing on the correlation between 3DP technology, therapy and outcomes. We screened 138 articles from PubMed, Scopus and Web of Science, selecting the 10 articles fulfilling the inclusion criteria, which were subsequently examined for the systematic review. The results showed that 3DP provides substantial advantages in terms of upper limb orthosis designed on the patient's needs. Moreover, seven research activities used biodegradable/recyclable materials, underlining the great potential of validated 3DP solutions in a clinical rehabilitation setting. The aim of this study was to highlight how 3DP could overcome the limitations of standard medical devices in order to support clinicians, bioengineers and innovation managers during the implementation of Healthcare 4.0.