Reshaping of Gait Coordination by Robotic Intervention in Myelopathy Patients After Surgery

Abstract

The Ossification of the Posterior Longitudinal Ligament (OPLL) is an idiopathic degenerative spinal disease which may cause motor deficit. For patients presenting myelopathy or severe stenosis, surgical decompression is the treatment of choice; however, despite adequate decompression residual motor impairment is found in some cases. After surgery, there is no therapeutic approach available for this population. The Hybrid Assistive Limb® (HAL) robot suit is a unique powered exoskeleton designed to predict, support, and enhance the lower extremities performance of patients using their own bioelectric signals. This approach has been used for spinal cord injury and stroke patients where the walking performance improved. However, there is no available data about gait kinematics evaluation after HAL therapy. Here we analyze the effect of HAL therapy in OPLL patients in acute and chronic stages after decompression surgery. We found that HAL therapy improved the walking performance for both groups. Interestingly, kinematics evaluation by the analysis of the elevation angles of the thigh, shank, and foot by using a principal component analysis showed that planar covariation, plane orientation, and movement range evaluation improved for acute patients suggesting an improvement in gait coordination. Being the first study performing kinematics analysis after HAL therapy, our results suggest that HAL improved the gait coordination of acute patients by supporting the relearning process and therefore reshaping their gait pattern.

Muscular Activity Modulation During Post-operative Walking With Hybrid Assistive Limb (HAL) in a Patient With Thoracic Myelopathy Due to Ossification of Posterior Longitudinal Ligament: A Case Report

“…There are some reports on neural activity changes by HAL in recent literature: brain activity changes in the primary motor cortex of subacute stroke patients immediately after using HAL (81), cortical excitability changes in the primary somatosensory cortex of spinal cord injury patients after 3 months of training (16), muscle synergy changes in the lower limbs of stroke patients (50), segmental coordination changes in in the lower limbs of myelopathy patients after surgery for thoracic OPLL (11), and activation in some muscles of chronic spinal cord injury patients during and after HAL training (17).…”

“…It actuates the electric motors embedded in the hips and knees of its exoskeleton in real time, amplifying bioelectric activation of the relevant muscles which are detected using surface electrodes attached on the hip and knee muscles. Previous studies using HAL for myelopathy (10)(11)(12), spinal cord injury (13)(14)(15)(16)(17), and post-surgery rehabilitation after total knee arthroplasty (18) reported improvement of walking ability after HAL training.…”

“…In previous studies on the application of HAL for postoperative gait rehabilitation of OPLL patients with thoracic myelopathy (10)(11)(12)(37)(38)(39), gait improvement is reported by comparing the state of the patient before starting and after finishing the entire robot-assisted intervention. However, this comparison hinders examination of the effect of the robot during the training per se, as well as how it differs from training without the robot.…”

Clinical research of lower extremity exoskeleton robot In post-stroke hemiplegic patients

“…In the nervous system, the diseases of central nerve, peripheral nerve, neuromuscular junction and muscle can lead to lower extremity dyskinesia [53] . There are many other clinical studies on exoskeleton in patients with lower extremity motor dysfunction, such as spinal cord injury [54] , postoperative [55] , agerelated gait disorder [14] , child cerebral palsy [39] , multiple sclerosis [56] and Parkinson's disease [57] , etc. Our research ndings not only exhibit more accurate clinical requirements for the research and renovation of exoskeleton robot, but also provides a new vision for clinical motor function improvement of lower extremity, including in stroke patients.…”

Research on patients-passive control strategy of the rehabilitation exoskeleton based on NN-SMC

“…An algorithm is proposed in Robot Suit HAL designed by University of Tsukuba to estimate patients' intentions so that HAL could comfortably and safely support a paraplegia patient's walking [6]. Furthermore, HAL takes the principle component analysis method to evaluate the working performance, which demonstrates the improvement of patients' gait coordination [7]. Brainmachine interfaces (BMIs) system is reviewed, which concludes that BMIs open the new possibilities in the assistance and rehabilitation fields [8].…”